NART 2016NANOFIBERS, APPLICATIONS

AND RELATED TECHNOLOGIES

Raleigh, North Carolina, USAMarriott City Center

September 13–15, 2016

PROGRAM

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thenonwovensinstitute.com

✴ TUESDAY, SEPTEMBER 13

Continental Breakfast7:30 AM – 8:30 AMRoom: STATE DEF

Welcome & Introduction8:45 AM – 9:00 AMRoom: STATE ABC

Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research, and Extension, William A. Klopman Distinguished Professor of Textile Materials, The Nonwovens Institute, North Carolina State UniversityDave Rousse, President, INDA, The Association of the Nonwoven Fabrics Industry

Keynote Speakers9:00 AM –10:30 AM

Nanofibers, New Market Opportunities in Regenerative MedicineAnthony Atala, MD, Wake Forest University Graduate School, Molecular and Cellular Biosciences

Current and Future State of NanotechnologyMichael Meador, PhD, Director, National Nanotechnology Coordination Office (NNCO)

Opportunities for Nanofibers in Water TreatmentHerve Buisson, Vice President, Veolia Water Solutions & Technologies

Break10:30 AM –11:00 AMRoom: STATE DEF

CONCURRENT SESSION ITUESDAY | 11:00 AM – 12:00 PMROOM: STATE AB

CONCURRENT SESSION IITUESDAY | 11:00 AM – 12:00 PMROOM: STATE C

1:00 PM – 3:00 PM 1:00 PM – 3:00 PM

Process Technologies Part IISession Chair: Stanislav Petrik, PhD, Director, Industry Relations, Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec

Centrifugal Spinning of Fine PVP/TA Fibres for Adsorption MediaTom O’Haire, Research Fellow, School of Design, University of Leeds

Reicofil® Meltblown – Improved Production Technologies for Future Filter DemandsMarkus Wüscht, Research Engineer, Reifenhäuser Reicofil GmbH

Engineered Nanocellulose Gel Fiber Production for Textile FinishingSuraj Sharma, PhD, Associate Professor Department of Textiles, Merchandising & Interiors, University of Georgia

Cellulose Acetate Nanofibers from Philippine Indigenous FibersJenneli E. Caya, Science Research Specialist, Philippine Textile Research Institute, Department of Science and Technology

Break3:00 PM – 3:30 PMRoom: State DEF

Energy part IISession Chair: Xiangwu Zhang, PhD, Professor, Associate Head & Director of Graduate Programs, Department of Textile Engineering, Chemistry and Science, North Carolina State University

Electrospun Particle/Polymer Fiber Mats as Fuel Cell and Battery ElectrodesPeter N. Pintauro, PhD, Professor of Chemical and Biomolecular Engineering, Department of Chemical and Biomolecular Engineering, Vanderbilt University

High-Performance Cobalt-Based Heterogeneous Electrocatalysts Synthetized by Electrospinning Yue-E Miao, PhD, State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University

Nanowire Devices for Electrochemical Energy StorageLiqiang Mai, PhD, Chair and Professor, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology

Optimization of Electrodes for Energy Storage of Supercapacitors from Electrospun ACNFs Kap Seung Yang, PhD, Professor and Director, Alan G. MacDiarmid Energy Research Institute, Chonnam National University, Department of Polymer Engineering, Chonnam National University

Process Technologies Part ISession Chair: Stanislav Petrik, PhD, Director, Industry Relations, Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec

Electrospinning with Modified Electrostatic FieldsGeorge G. Chase, PhD, Professor & Associate Chair for Research, Department of Chemical and Biomolecular Engineering, The University of Akron

Industrial-Scale Solution Blowing of Soy Protein and Fish Sarcoplastic Protein NanofibersAlexander L. Yarin, PhD, UIC Distinguished Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Chicago

Lunch12:00 PM – 1:00 PMRoom: State DEF

Energy Part ISession Chair: Xiangwu Zhang, PhD, Professor, Associate Head & Director of Graduate Programs, Department of Textile Engineering, Chemistry and Science, North Carolina State University

Electrochemical Performance of Carbon-Coated Tin Sulfide Nanofibers as Anodes for Lithium Ion BatteriesWan-Jin Lee, Professor, School of Chemical Engineering, Chonnam National University

Porous Polyacrylonitrile/Graphene Oxide Nanofiber Membrane Used as a Novel Separator for Achieving High-Performance Lithium-Sulfur BatteriesXiangwu Zhang, PhD, Professor, Associate Head & Director of Graduate Programs, TECS, Inaugural University Faculty Scholar, Alumni Distinguished Graduate Professor, Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University

3:30 PM – 5:30 PM 3:30 PM – 5:30 PM

CONCURRENT SESSION IWEDNESDAY | 8:30 AM – 10:30 AMROOM: STATE AB

CONCURRENT SESSION IIWEDNESDAY | 8:30 AM – 10:30 AMROOM: STATE C

Medical Part ISession Chair: Stephen J. Russell, PhD, Chair of Textile Materials and Technology, University of Leeds

Bioactive Nanofibres Enriched with Self-Assembling Peptides for Tissue RepairRobabeh Gharaei, PhD, Research Student, Giuseppe Tronci, PhD, Biomaterials Scientist, Robert P.W. Davies, PhD, Research Fellow, Parikshit Goswami, PhD, Professor, and Stephen J. Russell, PhD, Chair of Textile Materials and Technology; Professorial Representative; Group Leader: Textile Materials, School of Design, University of Leeds

Air Filtration Part ISession Chair: George G. Chase, PhD, Professor & Associate Chair for Research, Department of Chemical and Biomolecular Engineering, The University of Akron

Direct Formation of Hybrid Absorbent Nanofibers: Ultra-Fast Degradation of Chemical Warfare Agents using Metal-Organic Frameworks Grown Directly on NanofibersGregory N. Parsons, PhD, Alcoa Professor, Director, North Carolina State Nanotechnology Initiative, Department of Chemical and Biomolecular Engineering, North Carolina State University

Process Technologies Part IIISession Chair: Stanislav Petrik, PhD, Director, Industry Relations, Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec

Development of Structure and Morphology in Meltblown Nanofiber NonwovensGajanan Bhat, PhD, Director, Nonwovens Research Laboratory (UTNRL), Department of Materials Science and Engineering, The University of Tennessee

Electrospun Carbon Nanofibers and Their Composite Membranes for Energy StorageTianxi Liu, PhD, Professor, State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University

Liquid – Solid Transition During Dry Fiber SpinningDavid Lukáš, PhD, Chair of the Department of Nonwovens, Professor of Textile Technology, Technical University of Liberec, Centre for Nanomaterials, Advanced Technologies and Innovation of Technical University of Liberec

Turning Nanofibers into Products – Electrospinning from a Manufacturer’s PerspectiveIain Hosie, Technical Director, Founder, Revolution Fibers, New Zealand

Reception5:30 PM - 7:00 PMCapital City Club 150 Fayetteville Street, 28th Floor, Raleigh, NC 27601

Continental Breakfast 7:30 AM – 8:30 AMRoom: State DEF

Energy Part IIISession Chair: Peter Fedkiw, PhD, Department of Chemical & Biomolecular Engineering at North Carolina State University

Forcespinning® of Nanofibers for Energy Storage and Food Science ApplicationsMataz Alcoutlabi, PhD, Assistant Professor, Department of Mechanical Engineering, University of Texas-Pan American

Safety-Reinforced Poly(Propylene Carbonate)-Based All-Solid-State Polymer Electrolyte for Ambient-Temperature Solid Lithium BatteriesGuanglei Cui, PhD, Professor, Biometrics for Energy Storage Group, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

Tailoring Porous Scaffold of Thermoplastic PVA-Co-PE Nanofibers Based Membranes for High Efficient Energy ConversionDong Wang, PhD, College of Materials Science and Engineering, Wuhan Textile University

Fabrication, Characterizations, and Applications of Ultrastretchable and Conductive Fibers Michael D. Dickey, PhD, Professor, Department of Chemical & Biomolecular Engineering, North Carolina State University

✴ WEDNESDAY, SEPTEMBER 14

11:30 AM – 12:00 PM 11:30 AM – 12:00 PM

1:00 PM – 3:00 PM 1:00 PM – 3:00 PM

Modeling & Simulation Part IISession Chair: Hooman V. Tafreshi, PhD, Professor of Mechanical Engineering, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University

PA6/PANI Composite Nanofibers for Ammonia Sensors: A Combined Experimental and Simulation ApproachZengyuan Pang, Graduate Student, Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Department of Textile Engineering, Chemistry, and Science, North Carolina State University

Liquid FiltrationSession Chair: Herve Buisson, Vice President, Veolia Water Solutions & Technologies

Ion Exchange Microfiber Nonwovens Eunkyoung Shim, PhD, Assistant Professor, TECS, North Carolina State University

Removal of Heavy Metals and Toxins from Contaminated WatersJan Genzer, PhD, Celanese Professor, Associate Department Head, Department of Chemical & Biomolecular Engineering, North Carolina State University

Modeling & Simulation Part ISession Chair: Melissa A. Pasquinelli, PhD, Associate Professor, TECS Department of Textile Engineering, Chemistry, and Science, North Carolina State University

Modeling Water Droplet Equilibrium Shape on Fibers with Trilobal Cross-SectionsHooman V. Tafreshi, PhD, Professor of Mechanical Engineering, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University

Numerical Prediction of the Meltblowing laydown Alexander L. Yarin, PhD, UIC Distinguished Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Chicago

Lunch 12:00 PM – 1:00 PMRoom: STATE DEF

Air Filtration Part IISession Chair: George G. Chase, PhD, Professor & Associate Chair for Research, Department of Chemical and Biomolecular Engineering, The University of Akron

Visualization and Measuring of the Local Filtration Efficiency of a Nanofibrous FilterPetr Bílek, PhD, Professor, Head of Department, Technical University of Liberec

Modeling Filtration Performance of Nanofiber MediaHooman V. Tafreshi, PhD, Professor of Mechanical Engineering, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University

Electrospun Membranes Based on Natural Hydrocolloids for Bioremediation and Antibacterial ApplicationMiroslav Černík, PhD, Professor, Department of Nanomaterials in Natural Sciences, Centre for Nanomaterials, Advanced Technology and Innovation, Technical University of Liberec

Customisable Collagen Networks for Advanced Wound CareGiuseppe Tronci, PhD, Senior Research Fellow in Textile Materials Innovation for Healthcare, Clothworkers’ Centre for Textile Materials Innovation for Healthcare, School of Design, University of Leeds School of Dentistry, St. James’s University Hospital, University of Leeds

Hybrid Fiber-Optic/Nanofiber Sensors for Chemical and Biomedical Applications: A Proof-of-Concept StudyStanislav Petrik, PhD, Director, Industry Relations, et al., Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec

Break10:30 AM – 11:00 AMRoom: State DEF

Electrospun Mats with Orthogonal Fibers for Aerosol Filtration and/or Water Repellency Applications: A Computational StudyHooman V. Tafreshi, PhD, Professor, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University

Filtration Properties and Functionalization of PA6 Nanofiber/Woven Fabric CompositeEunkyoung Shim, PhD, Assistant Professor, The Nonwovens Institute, North Carolina State University

Nanofibers for High Efficiency Filtration: Performance and Cost SavingsJoshua Manasco, PhD, Elmarco, s.r.o.

CONCURRENT SESSION ITHURSDAY | 8:30 AM – 10:30 AMROOM: STATE AB

CONCURRENT SESSION IITHURSDAY | 8:30 AM – 10:30 AMROOM: STATE C

Medical Part IISession Chair: Saad Khan, PhD, Alcoa Professor, Director of the Graduate Program, North Carolina State University

Cellulose Nanofiber Environments Tailored for Microorganisms and Mammalian CellsJessica D. Schiffman, PhD, Assistant Professor, Department of Chemical Engineering, University of Massachusetts

Ab Initio Design of Nanofiber-Coated Surfaces for Mitigation of Microbial FoulingBahareh Behkam, PhD, Associate Professor, Department of Mechanical Engineering, Virginia Tech, School of Biomedical Engineering and Sciences, Virginia Tech, Macromolecules and Interfaces Institute

Single Cell Mechanobiological Studies Using Aligned Fiber NetworksAmrinder S. Nain, PhD, Assistant Professor, Department of Mechanical Engineering, Virginia Tech

Nanofibers for Drug DeliveryAlexander L. Yarin, PhD, UIC Distinguished Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Chicago

Break 10:30 AM – 11:00 AMRoom: State DEF

Nanoscale FunctionalizationSession Chair: Eunkyoung Shim

Supramolecular Nonwovens: Designing Nanofibrous Constructs from the Ground-UpRichard J. Spontak, PhD, Professor, Chemical and Biomolecular Engineering, North Carolina State University

Generation of Functional Coatings on Hydrophobic Surfaces through Deposition of Denatured Proteins Followed by Grafting from PolymerizationJan Genzer, PhD, Celanese Professor, Associate Department Head, Department of Chemical & Biomolecular Engineering, North Carolina State University

Surface Treatment of Nanofiber Media for Improved Hydrophobicity and Oleophobicity Fred Humiston, Director of Business Development, Sigma Labs

Antimicrobial Three Dimensional Woven Filters Containing Silver Nanoparticle Doped Nanofibers in a Membrane Bioreactor for Wastewater TreatmentYiping Qiu, PhD, Dean, Department of Technical Textiles, College of Textiles, Donghua University.

Structural Simulation of Nanofibrous Materials with Different Fiber RigiditiesHooman V. Tafreshi, PhD, Professor of Mechanical Engineering Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University

Tuning the Interfacial Characteristics of Fibrous Materials via Nanoscale SimulationsMelissa A. Pasquinelli, PhD, Associate Professor, TECS, Fiber and Polymer Science Program, North Carolina State University

Heat Induced and UV Induced Grafting of Poly(glycidyl methacrylate) on PBT Nonwovens for BioseparationsRuben Carbonell, PHD, Director, Golden Leaf Biomanufacturing Training and Education Center, North Carolina State University

Break & Postdoctoral Scholar and Graduate Student Displays session & Networking3:00 PM – 5:30 PMRoom: State DEF

Continental Breakfast 7:30 AM – 8:30 AMRoom: State DEF

Seed Strategies on the Functionality of Mineralized Nanofibers for Environmental RemediationEricka Ford, PhD, Assistant Professor, TECS, North Carolina State University

Nanofiber Membrane for Membrane DistillationTomáš Jiříček, Senior Researcher, Tomáš Lederer, PhD, Michal Komárek, PhD, Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec

✴ THURSDAY, SEPTEMBER 15

11:00 AM – 12:00 PM 11:00 AM – 12:00 PM

1:00 PM – 3:30 PM 1:00 PM – 3:30 PM

Analytical & Characterization of Nano MaterialsSession Chair: Jacob Jones

Visualizing Interfacial Phenomena in Bio-Derived Fiber Reinforced CompositesChelsea S. Davis, PhD, NRC Postdoctoral Fellow, Materials Science and Engineering Division, National Institute of Standards and Technology

Measuring Temperature at the Mesoscale with Optical ApproachesLaura I. Clarke, PhD, Professor, Department of Physics, North Carolina State University

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) Analysis: From Fibers to ForensicsChuanzhen Zhou, PhD, Research Scholar, Analytical Instrumentation Facility, North Carolina State University

Application of X-Ray Diffraction Methods to Textile MaterialsChing-Chang Chung, PhD, Postdoctoral Research Scholar, Department of Materials Science and Engineering, North Carolina State University and Analytical Instrumentation Facility, North Carolina State University

Mechanical Measurements and Microscopy as Characterization Tools for Nanofibrous WebsRussell E. Gorga, PhD, Associate Professor, TECS, Program in Fiber and Polymer Science, North Carolina State University

Long-Term Evaluation of Selected SPME Fibres – Implications for Polychlorinated Biphenyls AnalysisVojtěch Antoš, Pavel Hrabák, PhD, Michal Komárek, PhD, Martin Stuchlík, Technical University of Liberec

Optional tour of the pilot facilities at the Nonwovens Institute3:30 PM – 5:30 PM

Novel ApplicationsSession Chair: Benoit Maze, PhD, Research Assistant Professor, The Nonwovens Institute, North Carolina State University

Functional Nanofibers via Electrospinning: Approaches to Tailoring Drug ReleaseSaad Khan, PhD, Alcoa Professor, Director of the Graduate Program, Chemical and Biomolecular Engineering, North Carolina State University

Fighting Infections via Engineered NanofibersMahsa Mohiti-Asli, PhD, Research Assistant Professor, Biomedical Engineering, North Carolina State University

PHBV Fibres for Replacement Tendons and LigamentsTom O’Haire, Research Fellow, School of Design, University of Leeds

Nanofiber-Based Colorimetric BiosensingChristina Tang, PhD, Assistant Professor, Department of Chemical and Life Science Engineering, Virginia Commonwealth University

Tailored Wettability in Electrospun FibersMackenzie Geiger, Graduate Tech. & Research Assistant, North Carolina State University

Large-Scale Production of Polymer Nanofiber Nonwovens for Applications in Li-Ion Battery, and Air and Liquid Fine FiltrationHaoqing Hou, Department of Chemistry and Chemical Engineering, Jiangxi Normal University

Medical Part IIISession Chair: Saad Khan, PhD, Alcoa Professor, Director of the Graduate Program, North Carolina State University

Applicability of Silica Nanofibres in Medicine and BiotechnologyIrena Lovětinská Šlamborová, PhD, Assistant Professor, Petr Exnar, Associate Professor, Iveta Danilová, Textile Faculty, I. Veverková

Nanofibers as a Dry Form of Drug-Loaded Nanoparticles for Long-Term StorageShani L. Levit, Graduate Student and Christina Tang, PhD, Assistant Professor, Department of Chemical and Life Science Engineering, Virginia Commonwealth University

Lunch 12:00 PM – 1:00 PMRoom: State DEF

ElectrospinningSession Chair: Eunkyoung Shim, PhD, Assistant Professor, TECS, North Carolina State University

Advances in Electrospun Nanofiber Forming Technology in ChinaYanbo Liu, PhD, Professor/Senior Engineer, School of Textile Science and Engineering, Wuhan Textile University, School of Textiles, Tianjin Polytechnic University

Electrospray/Electrospinning of 3D Si/C Fiber Paper ElectrodesChunsheng Wang, PhD, Professor, Department of Chemical & Biomolecular Engineering, University of Maryland

Postdoctoral Scholar and Graduate Student Posters

Experimental Study of the Biax Spunblown® ProcessS. Barilovits, North Carolina State University, USA

Gel-Spun Polyacrylonitrile / Lignin Composite FibersC. E. Blackwell, North Carolina State University, USA

Soft and Stretchable Torsion, Touch, and Strain Sensors Using Core-Shell Liquid Metal MicrofibersC. Cooper, North Carolina State University, USA

Large-Scale Production of Polymer Nanofiber Nonwovens for Applications in Li-Ion Battery, and Air and Liquid Fine FiltrationH. Hou, North Carolina State University, USA

Process-Structure-Property relationship of PLA Meltblown Filter MediaM. Jafari, North Carolina State University, USA

Micro Fiber Orientation and its Effect in DesigningR. Jindani, North Carolina State University, USA

Electrospinning of Highly Conductive Low Weight Carbon Nanotube WiresS. King, Advanced Technology Institute, University of Surrey, UK

Bulk Polymer Additives Migration in Melt-blown Nonwovens for Oil and Alcohol Repellent ElectretsJ. Lavoie, North Carolina State University, USA

Structure-Property Relationships Of Gel Spun Polyvinyl Alcohol / Lignin Composite FibersC. Lu, North Carolina State University, USA

Pore Structure Analysis Through 3D ImagingB.Maze, North Carolina State University, USA

Effect of Nucleating Agent on Morphology and Filtration Performance of PolypropyleneS. Mohseni, North Carolina State University, USA

Engineering Interfaces between Graphene Oxide and IndustriallyQ. Pan, North Carolina State University, USA

Effect of Seeding on the Morphology of Calcium Carbonate Mineralized NanofibersY. Park, North Carolina State University, USA

Functionality of Poly(vinyl alcohol) Copolymers on the Morphology and Surface Chemistry of Electrospun NanofibersP. Rawat, North Carolina State University, USA

Conductive Inks Printing Patterning on Nonwoven FabricsH. Shahariar, North Carolina State University, USA

Nanofibers via Atomic Layer Deposition for Catalytic ApplicationsT. Uyar , UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, Turkey

A Polycaprolactone/Silk-Fibroin Nanofibrous Composite Combined with Human Umbilical Cord Serum for Subacute Tympanic Membrane Perforation; An In Vitro and In Vivo StudyM. Yeo, H. Lee, and G.H. Kim, PhD, Sungkyunkwan University, South Korea

September 13-15, 2016 Marriott City Center

Raleigh, North Carolina USA

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Concurrent Session: Process Technologies I

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Electrospinning with Modified Electrostatic Fields Y. Li and George G. Chase, PhD, Professor & Associate Chair for Research, Department of Chemical and Biomolecular Engineering, The University of Akron Electrospinning is widely used for producing micron and submicron sized polymer fibers with the aid of an electrostatic field to launch jets from a droplet of polymer solution. Polymer fibers in this size range are considered at the forefront of research in a number of application areas including medical devices, drug delivery, catalysis, membranes for fuel cells, and fluid-particle separations. Many parameters have been investigated empirically and theoretically for optimizing the operating conditions. Much attention was given to the design and control of the electrospinning fluid properties to achieve desired fiber morphologies and properties. Attention was also given to different approaches to fabrication of submicron fibers using pure electrospinning or combinations of electrospinning with other mechanical methods for drawing fibers (flowing gases, rotational inertia, and other mechanisms). Most electrospinning designs consider geometries where the electric field starts at fixed singular points (end of an aperture such as a needle) or linear points (such as a wire) and extend to a flat collector surface. The implied premise is the electric field should extend unhindered and along a mostly straight path to the collector to allow optimal stretching and elongation of the jet to produce small fibers. A few designs consider different geometries in which the electric field is deliberately directed along non-linear paths. These latter are useful for directing the fibers to collect in specific locations that may not be on a flat planar surface (such as the edges of disks or on cylinders). The latter are also useful for diverting fibers away from specific locations. To a large extent the electrospinning jet follows the electrical field flux lines. The jet by its nature carries charges that tend to repel each other and hence the jet spreads as it travels, but the center of mass of the jet follows the electrical field. We show here that by controlling the geometry of the field lines the jets can be directed to collect the fibers in desired locations. Several different designs are modeled and compared with experimental data in this paper.

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Industrial-Scale Solution Blowing of Soy Protein and Fish Sarcoplastic Protein Nanofibers A. Kolbasov1, Soumyadip Sett, PhD, Graduate Research Assistant1, Karen Boutrup Stephansen, PhD, Life Science Consultant2, Suman Sinha-Ray, PhD, Senior Researcher at Building Science & Technology Commercialization at USG1,3,4, Abhay Joijode, PhD, Research Engineer5, Mohammad A. Hassan, PhD, Douglas Brown, President6, Benoit Maze, PhD, Research Assistant Professor5, Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute5, Alexander L. Yarin, PhD, UIC Distinguished Professor1

1Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 2 BASE cph – Life Science Advisors 3Corporate Innovation Center, United States Gypsum 4Department of Materials Science and Engineering, Indian Institute of Technology 5The Nonwovens Institute, North Carolina State University 6BIAX-Fiberfilm Corporation Solution blowing is one of the most industrially viable processes for mass production of nanofibers without significant change of trade practices. In this work a novel industrially scalable approach to nanofiber production by solution blowing is demonstrated using Biax die. Blends of biopolymer soy protein isolate Clarisoy 100 and poly(ethylene oxide) were solution blown as aqueous solutions using a spinneret with 8 rows with 41 concentric annular nozzles. Nanofiber mats were collected on a drum, and samples with an area of the order of 0.1-1 m2 were formed in about 10 s. Solution-blowing was also adopted to form nanofibers from fish sarcoplasmic proteins (FSPs). FSP is a highly interesting biopolymer, especially due to its availability from the wastewater that can provide a huge source of this material, as well as increase the yield of the fish as a resource. Nanofiber mats containing different weight ratios (up to 90/10) of FSP in the FSP-nylon 6 blended nanofibers were formed from formic acid solutions, and compared to electrospun fibers made from the same solutions. The nanofiber mats produced by the two methods were characterized in terms of FSP content, fiber diameter distribution, fiber mat porosity, and mass of the fibers collected by the two processes. Moreover, the mechanical tests showed that up to 50% of nylon 6 could be replaced with FSP without compromising the mechanical properties, compared to pure nylon 6 nanofibers. Comparison of the yield showed that the production rate of solution-blowing was increased 30 fold in relation to electrospinning. Overall, this study reveals FSP as an interesting biopolymeric alternative to synthetic polymers, and the introduction of FSP to nylon 6 provides a composite with controlled properties.

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Concurrent Session: Process Technologies II

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Centrifugal Spinning of Fine PVP/TA Fibres for Adsorption Media Tom O’Haire, Research Fellow, Stephen J. Russell, PhD, Chair of Textile Materials and Technology; Professorial Representative; Group Leader: Textile Materials, and Christopher M. Carr, PhD, Chair of Textile Technology, Head of School, School of Design, University of Leeds A copolymer of polyvinylpyrrolidone and 1-triacontane (PVP/TA) is known to be highly hydrophobic. The hydrophobicity renders PVP/TA fibres potentially suitable for capturing and separating molecules from fluids through physical interactions. This ability to tailor the interaction between multi-component liquids and fibre surfaces to take advantage of phenomena such as mutual hydrophobicity and oleophilicity is important in numerous applications such as filter media, chemical sorbents and protective clothing. The number of adsorption sites for bonding and capture can be increased by forming the PVP/TA polymer in to fine, sub-micron fibres. This paper discusses the manufacture of this copolymer using centrifugal spinning/forcespinning. Centrifugal spinning has been proposed as a highly versatile and scalable alternative to electrospinning capable of processing polymer solutions and polymer melts. Centrifugal spinning relies on rotational inertial forces to generate a polymeric jet which is then elongated by aerodynamic and rotational forces. This approach was used to form nanofibrous webs from a PVP/TA co-polymer through melt spinning. This presentation will discuss the issue of disperse dye discharge in dye house effluent; the production of PVP/TA fibres via melt centrifugal spinning; the effect of processing conditions on fibre diameter; the brittle nature of the fibres and impact of copolymer fine structure; the application of these fibres as a capture agent and the “mutual hydrophobicity” which attracts and binds soils and disperse dyes to the surface of the fibre.

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Reicofil® Meltblown – Improved Production Technologies for Future Filter Demands Detlef Frey, Head of the Reicofil Technology Center, Markus Jansen, Research & Development Engineer, Markus Wüscht, Research Engineer, Reifenhäuser Reicofil GmbH Modern filter applications have to fulfill a huge variety of demands. Besides it´s filtration efficiency a certain mechanical resistance for pre- and post-processing is required. To save energy costs for the operation of fans and blowers, the influence of the pressure drop is more and more the center of attention. Regarding environmental sustainability and the life cycle of a filter a minimized pressure drop is desired and key element of the increasing demands. Especially the further growth of polluted air and the increasing request for air pollution prevention show the vital importance of filter applications in everyday life. Filtration of air borne pollution is a necessity in human environments. Because the number of filter applications is increasing, not only the technical feasibility of producing filter materials is important but rather their cost- efficient production. Overcoming the tradeoff between high throughputs or high production rates and a decreasing product performance will enable the production of disposable and low cost products with high filtration standards. A promising approach to fulfill those requirements and to develop modern filter media is a combination of several filter layers with different filament-diameters and –distributions as one combined product with an intentionally adjusted air permeability. In addition the nonwoven structure in the third dimension is getting more and more important for depth filtration purposes and for the use as a pre filter. To reduce the penetration of the fine filter section and to minimize material usage and pressure loss, Reicofil offers a new approach for producing high loft meltblown materials. This approach will enlarge the flexibility of their productions lines at the same time. Also an improved technology will be presented which fulfills the requirements of ultra-fine fiber meltblown material with a mean fiber diameter of ~500nm while matching the market demand of high productivity and annual outputs. For the present portfolio of meltblown standalone lines Reicofil will present new ideas and designs, to produce and develop nonwoven filter media.

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Engineered Nanocellulose Gel Fiber Production for Textile Finishing Suraj Sharma, PhD, Associate Professor, Lauren Tolbert, Student, Yunsang Kim, PhD, Research Associate, Eliza Lee, Research Technician II, Sergiy Minko, PhD, Professor, Department of Textiles, Merchandising & Interiors, University of Georgia This research was conducted to optimize the process for production of nanocellulose gel fibers for eventual textile finishing. Testing and developing procedures were conducted in order to produce the nanocellulose gel fiber that has abundant hydroxyl moieties to covalently bind to dye molecules as well as reduce initial water usage and eliminate the rinsing requirements typical for exhaustion dyeing. Production of nanocellulose gel starts with knife milling the waste paper pulp into fine powder, followed by pretreatment and mechanical delamination to produce engineered nanofibrillated cellulose (NFC) gel fibers. The gel was characterized for morphological, rheological and film forming potential for various applications, such as coating, coloration and biomedical. The process of gelling was also studied in order to understand the processing more extensively.

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Cellulose Acetate Nanofibers from Philippine Indigenous Fibers Jenneli E. Caya, Science Research Specialist, Zailla P. Flores and Nora B. Mangalindan, Chief, Research and Development Division, Philippine Textile Research Institute, Department of Science and Technology Polymeric nanofibers which are useful in a variety of medical applications, such as filtration devices, medical prosthesis, scaffolds for tissue engineering, wound dressings, controlled drug delivery systems and other uses as cosmetic skin masks, and for protective clothing have been developed. Banana trunks and pineapple leaves from commercial or corporate plantations are considered agricultural wastes and have no economic value compared to abaca which has a number of industrial uses. One thing in common among them is that celluloses from these sources are resilient enough to be extracted using mechanical and chemical processes making them good alternative raw materials in producing dissolving pulp other than wood. The pulp produced containing >90% α-cellulose is used as the starting material in producing CA that is subjected to electroprocessing to produce a fibrous nonwoven random mat. With the study conducted, we have demonstrated the possibility of obtaining banana, abaca and pineapple CA suitable for electrospinning into nonwoven fibrous mats of various weights and thickness for a number of applications in the medical and industrial sectors.

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Concurrent Session: Process Technologies III

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Development of Structure and Morphology in Meltblown Nanofiber Nonwovens Gajanan Bhat, PhD, Director, Nonwovens Research Laboratory (UTNRL), Kokouvi Akato, Graduate Research Assistant, and W. Han, Department of Materials Science and Engineering, The University of Tennessee Melt blowing is a technology that has been commercially used to produce microfibers. Recently, nanofiber nonwovens from various thermoplastic polymers have been successfully produced via the meltblowing process. Not only that submicron fiber nonwovens are produced without the use of any solvent, but also the production rates are very high with a good commercialization potential. Findings from this ongoing research with respect to structure and properties of meltblown nanofibers from various polymers produced, and the issues and challenges for commercial adaptation of this technology will be discussed. Special focus will be given to development of microstructure in PP and PLA during nanofiber meltblowing compared to regular microfiber meltblowing process, and its consequences on the properties and performance of the formed webs will be presented.

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Electrospun Carbon Nanofibers and Their Composite Membranes for Energy Storage Tianxi Liu, PhD, Professor, State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University Electrospinning is a simple technique to produce polymer fibers with submicron diameter, which can be further thermally treated to generate ultrafine carbon fibers (CNF) [1-5]. In this work, flexible CNF membranes with controllable morphology (e.g., fiber diameter, surface area, and porosity) and good electrical conductivity have been fabricated by combination of electrospinning and high-temperature carbonization, which can effectively act as potential binder-free electrode substrates. Hence, CNF-based nanocomposites with hierarchical structures have been facilely constructed by using CNF membrane as the building template, where low-dimensional electroactive nanoparticles (e.g., one-dimensional nanoneedles, and two-dimensional nanoplatelets) of metal oxides (hydroxides) (e.g., MnO2, and Ni(OH)2) and conducting polymers (e.g., polyaniline) are uniformly distributed on the CNF surface. Thus, a three-dimensional open structure is formed, which greatly improves the specific surface area of active materials for fast electrolyte transport as well as provides a highly conductive pathway for rapid charge-transfer reactions. Therefore, remarkably improved electrochemical energy storage capabilities and rate performance have been achieved, making electrospinning a promising technique for design and fabrication of electrospun carbon nanofibers and their composite membranes for next-generation energy storage applications.

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Liquid – Solid Transition During Dry Fiber Spinning M. Sivan1, P. Mikes, PhD, Assistant1,2, Jiří Chaloupek, PhD, Research Specialist1, Kateřina Strnadová, Graduate Student1, Maroš Tunák, PhD, Vice Dean1, David Lukáš, PhD, Chair of the Department of Nonwovens, Professor of Textile Technology, Head of Department of Nonwovens and Nanofiber Materials1,2

1Faculty of Textile Engineering, Technical University of Liberec 2Centre for Nanomaterials, Advanced Technologies and Innovation of Technical University of Liberec This work analyses the hydrodynamic stability of viscose polymeric solution jets created by drawing technology concentrating on the liquid-solid transitions. The analysis starts with estimations predicting the fastest growing rate and the assigned wavelength of the Plateau-Rayleigh instability. The results show that creation of the thread from a polymer solution droplet has a character of an immediate liquid-solid transition, where the solid has a form of a gel. A method of video records of the fiber drawing process aided by image analysis is employed to obtain capillary pressure distribution along the jet axis. These results confirm the quick creation of a solid-liquid coexistence due to a violation of constant mean curvature on the equilibrium liquid surface. The analysis follows with introduction of an evaporative model from the jet including the physical reason for enhanced evaporation with decreasing jet diameter. A flow of the solvent inside the jet is supposed to be at its surface only. It results in creation of a solid gel film as a skin of the jet. The film provides the system with both instant and sufficient hydrodynamic stability. The existence of such films are thereafter experimentally evidenced.

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Turning Nanofibers into Products – Electrospinning from a Manufacturer’s Perspective Iain Hosie, Technical Director, Founder, Revolution Fibers, New Zealand In recent years, the interest in electrospinning research and development has grown dramatically, with new nanofibrous materials and applications being reported in peer-review journals every month. Application areas are as broad ranging as medical devices, filtration, electronics, composites, energy generation and storage, sensing, acoustics and more. Despite the clear potential for nanofibers to be used in each of these industries, the uptake in terms of the number of commercialized products that use electrospun nanofiber remains very limited, with air filtration being the only sector in which they are used extensively. In this chapter, the current state of the electrospinning industry is discussed, including recent advances in commercial-scale electrospinning and other competing technologies. The challenges that are faced by commercial electrospinning companies are highlighted, helping to explain the limited commercialization and uptake of electrospinning by industry. To finish, some examples of nanofiber products that are currently available or being commercialized are given, with an outlook on what the future may hold for electrospun nanofiber technologies in the years to come.

15

Concurrent Session: Energy I

16

Electrochemical Performance of Carbon-Coated Tin Sulfide Nanofibers as Anodes for Lithium Ion Batteries Haeun Shin, Hojin Hwang, Wan-Jin Lee, Professor, School of Chemical Engineering, Chonnam National University With the rise in the world-wide demand for various mobile electronics, gadgets and electric vehicles (EVs), lithium ion batteries (LIBs) are promising candidates because of their environmental benignity and high energy density. To date, the considerable researches have been dedicated to develop the materials having better electrochemical performance for anode materials of LIBs such as carbonaceous materials, metal oxide and metal sulfide. Especially, metal sulfides (M = W, Mo, Sn, Ni and Fe) have recently been regarded as alternative anode materials due to their naturally abundance, low toxicity, high specific capacity, and excellent electrochemical stability. Even though there are remarkable achievements to design metal sulfides as anode materials, they still show limited performance because of their low structural stability. To improve integrity of structure, we report the anode material of the carbon-coated tin sulfide nanofibers. The carbon-coated tin sulfide nanofibers were synthesized through electrospinning, hydrothermal process of the composite solution consisting of thioacetamide, sucrose and Pluronic F127, followed by carbonization under nitrogen atmosphere. During the carbonization process, sucrose was converted into porous carbon by removing F127 embedded in sucrose. The porous carbon-coated tin sulfide nanofibers offer structural stability induced by the buffering effect, fast electron transfer by high electrical conductivity contributing with 1D structured nanofibers, and facile mass transfer caused by high contact area between electrode and electrolyte. As a result, the carbon-coated tin sulfide nanofibers represent good electrochemical performance and cycling stability.

17

Porous Polyacrylonitrile/Graphene Oxide Nanofiber Membrane Used as a Novel Separator for Achieving High-Performance Lithium-Sulfur Batteries Jiadeng Zhu, Graduate Student, Pei Zhu, Graduate Research Assistant, and Xiangwu Zhang, PhD, Professor, Associate Head & Director of Graduate Programs, TECS, Inaugural University Faculty Scholar, Alumni Distinguished Graduate Professor, Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University Sulfur has been considered as a promising cathode candidate for next-generation lithium batteries due to its high theoretical capacity (1675 mAh g-1) and energy density (2600 Wh kg-1). However, the practical applications of lithium-sulfur (Li-S) batteries are currently hindered by their severe self-discharge behavior. A porous polyacrylonitrile/graphene oxide (PAN/GO) nanofiber membrane which can be performed as a novel separator for Li-S batteries to achieve high stable capacity and excellent anti-self-discharge feature is presented here. A superior low retention loss of 5% can be obtained by this membrane even after a resting time of 24 h which is due to the relatively high energy binding between –C≡N and Li2S/Li-S radicals and the electrostatic interactions between GO and negatively charged species (Sn

2-). It is demonstrated that this as-spun PAN/GO nanofiber membrane with highly porous structure and excellent electrolyte wettability is a promising separator candidate for high-performance Li-S batteries.

18

Concurrent Session: Energy II

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Electrospun Particle/Polymer Fiber Mats as Fuel Cell and Battery Electrodes Peter N. Pintauro, PhD, H. Eugene McBrayer Professor of Chemical Engineering, Professor of Chemical and Biomolecular Engineering1, John Slack, Graduate Student1, Ethan Self, Graduate Student1, and Ryszard Wycisk, PhD, Research Associate Professor of Chemical and Biomolecular Engineering1, Matthew Brodt, PhD, Postdoctoral Research Associate2

1Department of Chemical and Biomolecular Engineering, Vanderbilt University 2Merck KGaA/Friedrich-Alexander-Universität Erlangen-Nümberg Electrospinning is gaining popularity as a convenient and robust technique for fabricating non-woven mats of sub-micron diameter polymer fibers. Although not as well studied, the technique can also be used to prepare particle/polymer fiber networks with high intra- and inter-fiber porosity. Such fibrous networks can be used as porous electrodes in fuel cells and batteries, where high interfacial electrode area, i.e., the accessibility of electrode material within a 3-D anode or cathode architecture, is of prime importance. In this talk, a review of recent experimental work on nanofiber mat architectures for hydrogen/air fuel cell cathodes and lithium battery anodes and cathodes will be presented, where the particle loading in the fibers is very high. The fuel cell work is focused on fibers containing carbon supported Pt or Pt-alloy powders with various perfluorosulfonic acid polymer binders. The fuel cell power output using such a cathode is very high for ultra-low Pt loadings. Additionally, carbon corrosion of nanofiber cathodes, as determined from voltage cycling experiments, can be minimized by proper adjustment of the hydrophilic/hydrophobic properties of the catalyst binder. For Li battery applications, nanofiber anodes have been prepared and evaluated, where the fibers are composed of either TiO2 and carbon powders with poly(acrylic acid) binder or carbon powder and poly(vinylidene fluoride) (PVDF). Here, the volumetric capacity of a fiber anode at charge/discharge rates of 1C-3C is considerably higher than that measured with a conventional thin film slurry anode. Electrospinning can also be used to prepare thick anodes with high areal capacities, e.g., 2.5 and 1.3 mAh/cm2 at charge/discharge rates of 1C and 2C, respectively. Similarly, Li battery nanofiber cathodes with LiCoO2 and carbon powder in a PVDF binder have been fabricated and evaluated at various areal capacities and C-rates. Experimental details for both fuel cell and battery electrodes will be presented in this talk, including the procedures for electrospinning fibers, the methods for characterizing the fiber mats, and the performance of the particle/polymer mats in a given application.

20

High-Performance Cobalt-Based Heterogeneous Electrocatalysts Synthetized by Electrospinning Yue-E Miao, PhD, State Key Laboratory of Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University High-performance electrocatalysts with excellent catalytic activity and long durability competitive to Pt are urgently necessary for the fast development of energy storage and conversion systems. Electrospinning has been proved to be an efficient technique to produce advanced fibrous materials with robust mechanical strength, fine flexibility, large surface area, and ease of scalable synthesis from various materials (e.g., polymer, ceramic, carbon) for diverse applications. Herein, nitrogen-doped carbon nanofiber (NCNF) membrane has been developed via electrospinning, acting as a three-dimensionally networked and conductive template for immobilization of electrochemically active cobalt-based nanoparticles. Thus, cobalt-based NCNF composite fibers with hierarchical structures are obtained, which subtly combine the synergistic effects between the electroactive cobalt-based nanoparticles, efficient surface nitrogen doping and highly conductive NCNF network. Therefore, the cobalt-based NCNF composite exhibits excellent catalytic activity toward oxygen reduction reactions with positive Epeak potential, high current density and superior durability over the commercial Pt/C catalyst, being promising noble metal-free catalysts for practical fuel cell applications.

21

Nanowire Devices for Electrochemical Energy Storage Liqiang Mai, PhD, Chair Professor, State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology One-dimensional nanomaterials can offer large surface area, facile strain relaxation upon cycling and efficient electron transport pathway to achieve high electrochemical performance. Hence, nanowires have attracted increasing interest in energy related fields. We designed the single nanowire electrochemical device for in situ probing the direct relationship between electrical transport, structure, and electrochemical properties of the single nanowire electrode to understand intrinsic reason of capacity fading. The results show that during the electrochemical reaction, conductivity of the nanowire electrode decreased, which limits the cycle life of the devices. Then, the prelithiation and Langmuir-Blodgett technique have been used to improve cycling properties of nanowire electrode. Recently, we have fabricated hierarchical MnMoO4/CoMoO4 heterostructured nanowires by combining "oriented attachment" and "self-assembly". The asymmetric supercapacitors based on the hierarchical heterostructured nanowires show a high specific capacitance and good reversibility with a cycling efficiency of 98% after 1,000 cycles. Furthermore, we fabricated Li-air battery based on hierarchical mesoporous LSCO nanowires and nonaqueous electrolytes, which exhibits ultrahigh capacity over 11000 mAh g-1. We also designed the hierarchical zigzag Na1.25V3O8 nanowires with topotactically encoded superior performance for sodium-ion battery cathodes.7 Our work presented here can inspire new thought in constructing novel one-dimensional structures and accelerate the development of energy storage applications.

22

Optimization of Electrodes for Energy Storage of Supercapacitors from Electrospun ACNFs Chang Hyo Kim3, Yoong Ahm Kim2, Kap Seung Yang, PhD, Professor and Director1, 2

1Alan G. MacDiarmid Energy Research Institute, Chonnam National University 2Department of Polymer Engineering, Chonnam National University 3Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST) The electrospun carbonized fibers were investigated for the electrodes of supercapacitors. The electrochemical performances of the electrodes (ACNFs) were investigated on the basis of the pore size controlled by activation media and activation temperature, and were investigated for relationship between the pore size and the capacitance/energy density. The electrolytes chosen were 6M KOH and ionic liquid (EMI-TFSI; 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) in varying the ion size. Especially, the ionic liquid was chosen for high energy density performance from large potential range. The maximum electrochemical performances of the supercapacitor electrodes tuned by pore size were specific capacitances of 220F/g in 6M KOH and 160F/g in EMI-TFSI, energy density of 27.7 Wh/kg in 6M KOH and 246 Wh/kg in EMI-TFSI.

23

Concurrent Session: Energy III

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Forcespinning® of Nanofibers for Energy Storage and Food Science Applications Mataz Alcoutlabi, PhD, Assistant Professor, Victor Agubra, PhD, Postdoctoral Research Associate, Luis Zuniga, Graduate Student, David Flores, Graduate Student, and David De la Garza, Student, Department of Mechanical Engineering, University of Texas-Pan American

Our research team at UTRGV is involved in several research projects that mainly focus on the use Forcespinning® technology to produce polymer nanofibers and polymer/ceramic nanofiber composites for use in a wide variety of potential applications such as energy storage devices tissue engineering and food science/safety. Recently, Sarkar, Lozano and coworkers developed the Forcespinning™ (FS) method to mass produce nanofibers (NFs) with desired structure and performance. FS is a technology that relies on applying a centrifugal force with an externally imposed rotational constraint to a solution or melt to produce submicron and nanometer fibers. This presentation introduces ForceSpinning®, a cost effective technique capable of mass producing high quality fibrous mats, which is completely different technology than other methods such as electrospinning and melt blowing methods. Here we present results on the use FS method to produce NFs for energy storage devices and food safety applications such as rechargeable Li-ion and Na-ion batteries supercapacitors and biomedical sensors. The focus of this work is on the design, synthesis, screening, and in-depth characterization of nanostructured materials with good properties and performance and low cost. The ultimate goal of this project is the development of low-cost, high capacity, long cycle life materials for Li-ion, Na-ion batteries and biosensors. Several systems of composite NFs were prepared by FS method such as polymer Nonwoven mats, Sn/C, Si/C and SnO2/C composite

nanofibers. The results obtained on the properties and performance of these FS NF-based composite systems are discussed in details.

25

Safety-Reinforced Poly(Propylene Carbonate)-Based All-Solid-State Polymer Electrolyte for Ambient-Temperature Solid Lithium Batteries Guanglei Cui, PhD, Professor, Biometrics for Energy Storage Group, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences Solid polymer electrolyte is regarded as a perfect way to handle the potential safety issues of liquid lithium-ion battery. Herein, we reported a new class of safety-reinforced, wide voltage window and ambient temperature polymer poly(propylene carbonate)-based solid polymer electrolyte for high-performance lithium battery. It was demonstrated that such solid polymer electrolyte exhibited comprehensive performance in terms of higher ionic conductivity (4.3×10-4 S cm-1) at 25oC, wider electrochemical window (> 4.6 V), better mechanical strength (25 MPa) and superior rate capability (3 C) at ambient temperature than those of pristine poly (ethylene oxide) solid polymer electrolyte. In addition, LiFePO4/Li cell employing this solid polymer electrolyte can charge and discharge normally even at 120oC, which indicating remarkably improved thermal dimensional stability and reliability of this solid polymer electrolyte. Moreover, the aluminum-pouch-type lithium cells assembled with such solid polymer electrolyte could light a red light emitting diode (LED) lamp and without suffering from internal short-circuit failures even after cutting off the part of lithium batteries. There is no doubt that the development of highly safe and ambient temperature poly(propylene carbonate)-based all-solid-state polymer electrolyte would provide a prospective scope for high-performance solid lithium batteries.

26

Tailoring Porous Scaffold of Thermoplastic PVA-Co-PE Nanofibers Based Membranes for High Efficient Energy Conversion Qiongzhen Liu, Jiahui Chen, Bo Wang, Ming Xia, Yuedan Wang, Mufang Li, Ke Liu, Dong Wang, PhD, College of Materials Science and Engineering, Wuhan Textile University Polymeric nanofibers have a small size and high surface area characteristics, which provides surface functionalization, thus they have great potential with applications in energy storage and conversion, and related flexible electronics. Novel environmentally benign technique for nanofibers on the basis of Melt-Extrusion-Phase-Separation method, have been demonstrated a facile process for large scale fabrication of a variety of polymeric nanofibers. Among these nanofibers, Poly(vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibers in the form of continuous bundle yarns can be easily dispersed into a stable nanofibers suspension, which offers the possibility for construction of nanofibrous membrane with controllably porous scaffold. Moreover, PVA-co-PE nanofibers possess abundant active hydroxyl groups, which can serve as reactive sites for versatile functionalization. This work addresses tailoring porous scaffold of thermoplastic PVA-co-PE nanofibers based membranes for high efficient energy conversion, which can be used as separators for Lithium-ion batteries, anodes for Microbial fuel cells (MFCs), and electrodes for super-capacitor. Our NFs/PET/NFs separator with 50-150 nm tortuous pores have shown high electrolyte-affinity and ionic conductivity, as well as improved cycling stability of lithium-ion cells. Our hierarchical PPy/NFs/PET anode affords an open porous and three dimensional interconnecting conductive scaffold with larger surface roughness. This MFc achieves an ultra-high power density of 2420 mW m-2 with E. coli. as the microbial catalyst, which is approximately 17 times higher compared to a commercial C-cloth. Considering the low cost, low weight, facile fabrication, and good winding, our thermoplastic PVA-co-PE nanofibers promises a great potential for high-efficient energy conversion filed in a large scale.

27

Fabrication, Characterizations, and Applications of Ultrastretchable and Conductive Fibers Ying Liu, PhD, Postdoctoral Research Scholar1, Rashed Khan, Graduate Student1, Ju-Hee So, Graduate Student1, Christopher Cooper, Student1, Dishit Parekh, Graduate Research Assistant1, Benham Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute1, Michael D. Dickey, PhD, Professor1, Shu Zhu, Graduate Student2 1Department of Chemical & Biomolecular Engineering, North Carolina State University 2University of Pennsylvania Fiber-based materials that are conductive and stretchable are highly desired for flexible and stretchable electronics, wearable devices, and other multifunctional textiles. Our research team created highly conductive and ultrastretchable fibers without compromising the mechanical properties of the fibers by injecting a liquid metal alloy into the core of stretchable hollow fibers. These core-shell structured fibers are conformal, flexible, soft, and maintain conductivity to 1000% strain. The liquid metal core has metallic conductivity, low toxicity, and low viscosity. The hollow shell can be fabricated by various elastomers such as Kraton, Hytrel, and Pebax via commercially available melt extrusion processes. Mechanical characterization has shown negligible impact of liquid metal core on the mechanical properties of the fibers. The relationship between process parameters, materials and the electrical/mechanical properties of fibers has been studied. The progress of the fabrication of smaller fibers and continuous process of polymeric hollow shell and liquid metal core will be discussed.

28

Concurrent Session: Medical I

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Bioactive Nanofibres Enriched with Self-Assembling Peptides for Tissue Repair Robabeh Gharaei, PhD, Research Student, Giuseppe Tronci, PhD, Biomaterials Scientist, Robert P.W. Davies, PhD, Research Fellow, Parikshit Goswami, PhD, Professor, and Stephen J. Russell, PhD, Chair of Textile Materials and Technology; Professorial Representative; Group Leader: Textile Materials, School of Design, University of Leeds Self-assembling peptides (SAPs) have been the focus of research in the last two decades and have shown to offer great promise in hard and soft tissue repair as well as in controlled drug delivery. The 11-residue family of peptides (P11-X) consists of negatively or positively charged amino acid (AA) residues in combination with hydrophobic AA residues that self-assemble hierarchically into β-sheet tapes, and above a critical concentration (c*), form hydrogen bonded hydrogels [1,2]. However, these self-assembled peptide hydrogels often suffer from poor mechanical strength and lack of structural stability. A potential route to address this challenge is the incorporation of SAPs within synthetic fibres to deliver structurally reinforced peptide enriched fabrics [3]. In this work, poly (ε-caprolactone) (PCL) was chosen as a base polymer with the aim of delivering P11-4 (CH3COQQRFEWEFEQQNH2) and P11-8 (CH3COQQRFOWOFEQQNH2) peptides within fibrous webs. This presentation will discuss the scientific aspects of self-assembling peptides; the production of PCL/SAP-containing fibres via electrospinning; the effect of processing conditions on fibre diameter; the secondary structure of peptides before and after electrospinning; the behavior of the fibres in biological conditions and the bioactivity of PCL/SAPs fibres in relation to the nucleation of hydroxyapatite.

30

Electrospun Membranes Based on Natural Hydrocolloids for Bioremediation and Antibacterial Application Vinod Vellora Thekkae Padil, PhD, Senior Researcher, and Miroslav Černík, PhD, Professor, Department of Nanomaterials in Natural Sciences, Centre for Nanomaterials, Advanced Technology and Innovation, Technical University of Liberec The recent advances and potential applications of electrospun nanofibers fabricated from natural and synthetic polymers for water treatment, food production, biotechnology, environment and energy have immensely conversed. The research work describes a ‘green’ method for the fabrication of electrospun nanofibrous membranes based on tree gum hydrocolloids such as Arabic (GA), Karaya (GK) and Kondagogu (KG). The present study focuses on the effect of electrospinning blended solutions of GA, GK or KG with PVA or PEO, additives which influence system parameters and process parameters, electrospun fibers characterizations, and impending applications in remediation of toxic metals and removal of nanoparticles from aqueous environment. The functionality of the nanofibrous membranes can be enhanced by various plasma treatments which improves specific surface area, water contact angle, surface porosity, roughness and hydrophobic properties. Besides, the antibacterial properties of the functionalized electrospun nanofibrous membranes would also be highlighted.

31

Customisable Collagen Networks for Advanced Wound Care Giuseppe Tronci, PhD, Senior Research Fellow in Textile Materials Innovation for Healthcare1,2, Jie Yin, PhD, Research Fellow1,2, Roisin Holmes, Research Student2, David J. Wood, PhD, Chair in Biomaterials, Director of Research and Innovation, Biomaterials and Tissue Engineering Research Theme Lead, Professor2, Stephen J. Russell1, PhD, Chair of Textile Materials and Technology; Professorial Representative; Group Leader: Textile Materials

1Clothworkers’ Centre for Textile Materials Innovation for Healthcare, School of Design, University of Leeds 2School of Dentistry, St. James’s University Hospital, University of Leeds Chronic wounds, such as venous leg ulcers, represent a significant healthcare burden worldwide. The design of advanced chronic wound dressings enabling effective wound exudate management is a promising route to accelerated healing, although it remains a challenge from a material and manufacture standpoint. We have previously reported the formation of mechanically competent, highly-swollen hydrogels based on photo-induced covalent networks of functionalised type I rat tail collagen. Building on this knowledge, this study investigated (i) the identification of a medical grade source allowing for the formation of atelocollagen network variants with comparable properties to previous rat tail collagen materials, (ii) the evaluation of hydrogel healing capability in a diabetic wound model in vivo, and (iii) the network customisation in bespoke material formats, i.e. wet stable fibres and fabrics. The presentation will focus on the design, synthesis, and manufacture of collagen hydrogels, wet-spun fibres and related fabrics; structure-property relationships; and impact of obtained materials in wound healing in vivo.

32

Hybrid Fiber-Optic/Nanofiber Sensors for Chemical and Biomedical Applications: A Proof-of-Concept Study Stanislav Petrik, PhD, Director, Industry Relations, et al., Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec Nanofibers are known for their exceptional surface area and wide opportunities for their functionalization. These properties have been attractive for various sensor applications, however, mostly electric sensing principles have been reported. In this presentation, a novel patent-pending approach based on optical detection will be described. Various functionalized nanofiber materials have been used to demonstrate feasibility of realization of miniature sensors of biomedical and chemical values (enzymes reactions, metal ions content, etc.). Compactness and sensitivity of the sensors are significantly enhanced through original hybrid fiber-optic/nanofiber design.

33

Concurrent Session: Modeling & Simulation I

34

Modeling Water Droplet Equilibrium Shape on Fibers with Trilobal Cross-Sections Mana Mokhtabad Amrei, PhD, Research Assistant at Porous Media and Multiphase Flow Lab and Hooman V. Tafreshi, PhD, Professor of Mechanical Engineering, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University The equilibrium shape of water droplets on fibers with trilobal cross-sections is studied in this work via numerical simulation. Specific attention has been paid to droplet shape on trilobal fibers having lobes with different length-to-diameter ratios. In addition, the effects of droplet volume and hydrophilicity/hydrophobicity of the fiber material on the droplet equilibrium shape are investigated in detail. Our simulation results indicated that fibers with longitudinal grooves e.g., trilobal fibers, promote droplet spreading along the fibers when the fibers are hydrophilic. It was also found that the effects of fiber cross-sectional shape on droplet detachment volume, the maximum droplet volume that the fiber can hold, are relatively weak.

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Numerical Prediction of the Meltblowing laydown Arkaprovo Ghosal, Graduate Student1, Suman Sinha-Ray, PhD, Senior Researcher at Building Science & Technology Commercialization at USG1,2,3, Alexander L. Yarin, PhD, UIC Distinguished Professor1, Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute4

1Department of Mechanical and Industrial Engineering, University of Illinois at Chicago 2Corporate Innovation Center, United States Gypsum 3Department of Materials Science and Engineering, Indian Institute of Technology 4North Carolina State University A numerical model was developed to simulate the three-dimensional structure and porosity of laydown formed on a moving screen in meltblowing. Numerical solutions of the system of quasi-one-dimensional equations of the dynamics of free liquid polymer jets moving, cooling and solidifying when driven by the surrounding air jet were found. Multiple viscoelastic polymer jets are considered simultaneously when they are deposited on a moving screen and forming a joint nonwoven laydown. The results reveal the three-dimensional configuration of the laydown and, in particular, its porosity and permeability, as well as elucidate the dependence of the laydown structure/architecture on the forming conditions, e.g. the velocity of the screen motion. Surface and volumetric porosities were predicted and found to be different. It was found how an increase in the velocity of the collector screen increases the porosity and permeability of meltblown nonwoven laydown.

36

Concurrent Session: Modeling & Simulation II

37

PA6/PANI Composite Nanofibers for Ammonia Sensors: A Combined Experimental and Simulation Approach Zengyuan Pang, Graduate Student1,2, Melissa A. Pasquinelli, PhD, Associate Professor, TECS2, Qufu Wei, PhD, Professor1

1Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University 2Department of Textile Engineering, Chemistry, and Science, North Carolina State University Ammonia, a flammable gas, widely exists in the environment, and is often emitted by many agents used in our daily life. Even low concentrations of ammonia can adversely affect human health. Thus, there is a need to develop technologies for monitoring the concentration of ammonia in air. We studied the use of polyamide 6/polyaniline (PA6/PANI) composite nanofibers for this purpose. PA6/PANI composite nanofibers were prepared by in situ polymerization of aniline with electrospun PA6 nanofibers as templates and hydrochloric acid (HCl) as a doping agent. Structural, morphological and ammonia sensing properties of the prepared PA6/PANI composite nanofibers were tested and evaluated through scanning electron microscopy (SEM), Fourier Transform Infrared (FT-IR) Spectroscopy and a home-made test system. Complementary molecular dynamics (MD) simulations were performed to explain how ammonia molecules interact with HCl-doped PANI chains, thus providing insights into the molecular-level details of the ammonia sensing performances of this system. This information can be used to direct the design of new materials with excellent gas sensing properties.

38

Structural Simulation of Nanofibrous Materials with Different Fiber Rigidities D.G. Venkateshan1, S. Yousefi1, M.A. Tahir1, Hooman V. Tafreshi, PhD, Professor of Mechanical Engineering1 and Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute2 1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University, 2North Carolina State University In this talk, we present a mass–spring–damper model that we have developed to study the morphology of nanofibrous materials in three-dimensional domains. The uniqueness of the algorithm developed in this work is that it allows the fibers to conform to the geometry of the surface on which they deposit. In particular, our mass–spring–damper model is very efficient in capturing the fiber’s curvature at fiber–fiber crossovers, which is crucially important for obtaining accurate estimates of the mats porosity. The algorithm is implemented in a C++ computer program, and is used to study the effects of fiber rigidity, fiber diameter(s), and fiber orientation on the thickness and porosity of electrospun mats. The porosity of our virtual fibrous mats was particularly found to depend on fibers tendency to bend at the fiber-fiber crossovers.

39

Tuning the Interfacial Characteristics of Fibrous Materials via Nanoscale Simulations Melissa A. Pasquinelli, PhD, Associate Professor, TECS1, Ya-Ting Su, PhD1, Syamal S. Tallury, Graduate Student1,2 Russell E. Gorga, PhD, Associate Professor, TECS1 and Richard J. Spontak, PhD, Professor1,2,3

1Fiber and Polymer Science Program, North Carolina State University 2Materials Science and Engineering, North Carolina State University 3Chemical and Biomolecular Engineering, North Carolina State University

By employing nanoscale (molecular) simulation tools with complementary experiments, the characteristics of polymer composites can be predicted and tuned at the nanoscale as a function of the chemical composition of the system as well as the conditions during processing. We will present the results of a systematic study of how polymer processing conditions can induce degradation, especially at the interface in bicomponent polymer systems; experiments validated that interfacial degradation yields a reduction in the adhesion strength and mechanical properties of the polymer fibers. We will also present the use of molecular simulations to tune the nanoscale characteristics of bicomponent polymer fibers in which experiments reveal that the interface is a critical factor in the thermal actuation of shape memory.

40

Heat Induced and UV Induced Grafting of Poly(glycidyl methacrylate) on PBT Nonwovens for Bioseparations Ruben G. Carbonell (Speaker), PhD, Frank Hawkins Kenan Distinguished Professor of Chemical Engineering, Director, Golden LEAF Biomanfacturing Training and Education Center (BTEC), Director, William R. Kenan, Jr. Institute for Engineering, Technology and Science, Michael Heller, Graduate Student, Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute, North Carolina State University and Kellie Esinhart, Clinical Trial Administrator, Chiltern International Polybutylene terephthalate (PBT) nonwovens were successfully grafted with poly(GMA) using a heat induced grafting (HIG) approach using the thermal initiator benzoyl peroxide. The grafting method resulted in uniform and conformal grafted layers around the PBT fibers that were functionalized as anion and cation exchangers for protein capture. Equilibrium protein binding capacities as high as 200 mg of protein per gram of fabric were observed. The equilibrium binding capacities for protein adsorption to the HIG grafted materials were reached within minutes, compared to UV grafted polyGMA ion exchange fabrics which reached equilibrium protein binding capacities in hours, even though they had the same weight % of grafted layers. However, UV grafted ion exchange nonwoven fabrics were capable of binding between 5 to 7 times more protein per mass of fabric at equilibrium than the HIG materials. It was found that the HIG materials showed a decrease in binding capacity with increased molecular weight of the solute that was much steeper than the drop observed with UV grafted materials. These observations indicate that even though the weight % of grafting is the same for HIG and UV grafting, the HIG grafted layers are significantly thinner and have a lower porosity in solution than the UV grafted brush layers.

41

Concurrent Session: Air Filtration I

42

Direct Formation of Hybrid Absorbent Nanofibers: Ultra-Fast Degradation of Chemical Warfare Agents using Metal-Organic Frameworks Grown Directly on Nanofibers Junjie Zhao, PhD, Graduate Research Assistant1, Dennis T. Lee, Graduate Student1, Heather F. Barton, Graduate Student1, Robert W. Yaga, Environmental Scientist2, Morgan G. Hall3, Ian R. Woodward1, Christopher J. Oldham, PhD, Postdoctoral Fellow1, Howard J. Walls, PhD, Research Chemical Engineer2, Gregory W. Peterson, Chemical Engineer3 and Gregory N. Parsons, PhD, Alcoa Professor, Director, North Carolina State Nanotechnology Initiative1 1Department of Chemical and Biomolecular Engineering, North Carolina State University 2RTI International 3Edgewood Chemical Biological Center The threat associated with chemical warfare agents (CWAs) motivates the development of novel materials to provide long-term protection in a reduced burden. Metal-organic frameworks (MOFs) have been recently shown as highly effective catalysts for detoxifying CWAs, but challenges still remain for integrating MOFs into functional filter media or protective garments. Here, we report a series of MOF-based nanofiber composites for fast degradation of CWAs. We found ALD TiO2 coatings deposited onto PA-6 nanofibers enable the formation of conformal Zr-based MOF thin films including UiO-66, UiO-66-NH2 and UiO-67. XRD and BET confirm that these MOF coatings are crystalline and high porous. Cross-sectional TEM images show that these MOF crystals nucleate and grow directly on and around the nanofibers, indicating strong adhesion to the substrates. The catalytic activities of the MOF-functionalized nanofibers were evaluated for degrading a CWA simulant Dimethyl 4-Nitrophenyl Phosphate (DMNP) and a nerve agent O-Pinacolyl Methylphosphonofluoridate (GD, or Soman). Half-lives of DMNP are less than 8 min with UiO-66-NH2 and UiO-67 thin films on PA-6@TiO2 nanofibers, while all the three types of Zr-based MOF coatings on nanofibers show ultra-fast destruction of GD with half-lives as short as 2 min. The results demonstrate the excellent catalytic performance of our MOF-nanofiber composites, and also show great promise for the development of gas filters, chemical sensors, and potentially smart textile materials.

43

Electrospun Mats with Orthogonal Fibers for Aerosol Filtration and/or Water Repellency Applications: A Computational Study Thomas M. Bucher, Graduate Student, Mana M. Ameri, Graduate Student, and Hooman V. Tafreshi, PhD, Professor, Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University Advances in nanofiber fabrication techniques (e.g., electrospinning) have come to allow control over fiber distribution and orientation such that ordered structures with fibers arranged in layers orthogonal to one another can potentially be produced. Such specialized fibrous structures could lead to benefits in several applications, two of which are the subject of this talk. They can serve as a nanosieve designed and placed on the downstream side of a conventional nonwoven filter to enhance its performance (collection efficiency for a given pressure drop). Such structures would also have properties suitable for superhydrophobic applications, allowing their wetting resistance to be predictable for a range of porosities, fiber diameters, and contact angles. This talk summarizes work done in both areas, relating coating performance back to microstructural and surface properties. We will also discuss significant observations that emerged from these studies, introducing tradeoffs and other considerations for coating design in either application.

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Filtration properties and functionalization of PA6 Nanofiber/Woven Fabric Composite Eunkyoung Shim, PhD, Assistant Professor, Ilkay Ozsev Yuksek, PhD, Textile Engineering, Chemistry and Science, College of Textiles, North Carolina State University; and Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute, North Carolina State University We have produced woven/polyamide 6 (PA6) nanofiber composites to achieve high filtration efficiency without causing excess pressure drop. We have controlled electro spinning condition and polymer concentrations and investigate their effect on nanofiber web structures, filtration properties and air permeability. We successfully produced bead-free smooth nanofibers webs with average fiber diameter of as small as 47nm. By depositing very thin layer of nanofiber web (basis weight ranges of 0.05~0.5g/m2), we have achieved at least 200% improvement of filtration efficiency with only 20% increase in pressure drop. We also produced nanofiber/metal oxide nanoparticle composite fibers with single step in situ electrospinning to functionalize PA6 nanofiber webs. Al2O3, TiO2, ZnO and Fe2O3 nanoparticles with different particle size and forms are used and their effects of nanofiber morphology were investigated. We have found metal oxide nanoparticles incorporate in PA6 nanofiber web provide photocatalytic reaction.

45

Nanofibers for High Efficiency Filtration: Performance and Cost Savings Joshua Manasco, PhD2, Ivan Ponomarev2, PhD, R&D Chemist, Project Manager, and Chris Sipes1, Director, Filtration and Nonwovens 1Elmarco, Inc. 2Elmarco, s.r.o. Nanofibers have been shown both theoretically and empirically to have the ability to provide a superior figure of merit (alpha/gamma) in air filter media over other larger fiber technologies. Nanofibers provide high specific surface area and a small, interconnected pore structure that allows a very low basis weight coating to achieve high filtration efficiencies while maintaining lowered pressure drop. In this study, we will first describe the contribution of the nanofiber layer’s characteristics on the figure of merit and MPPS (most penetrating particle size). The investigated characteristics include the configuration of the layer (SNS, SNNS, SNSN), basis weight, mean fiber diameter, and adhesion to the substrate. Secondly, filter makers need rolled stock with appropriate formatting as feedstock for matching their converting processes and downstream applications. Nanofibers can be difficult to transfer to this rolled stock and maintain performance properties useful to filtration applications due to their fragility and poor natural adhesion to common rolled good materials. Additionally, durability requirements for electrostatic discharge and pulse testing further place challenges for adoption of nanofibers in filtration applications. A third challenge for nanofibers in filtration applications is related to converting equipment necessary to form media into full filter format. Nanofibers must be able to withstand downstream processes in a filter converting operation such as winding/unwinding, lamination and pleating. This presentation will address performance requirements for nanofiber media, material handling challenges, and test standards relevant to making nanofibers useful for filtration applications. We will take a multi-pronged approach to solving the nanofiber durability/process-ability issue by looking at 1) Substrate design, 2) Nanofiber adhesion systems, 3) Fiber to fiber bonding (cohesion), and 4) Polymer selection. We will combine this approach with systematically studying the effects of the aforementioned in the downstream processing/specification protocol necessary for ISO16890/EN1822 and ASHRAE 52.2.

46

Concurrent Session: Air Filtration II

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Visualization and Measuring of the Local Filtration Efficiency of a Nanofibrous Filter Petr Bílek, PhD, Jakub Hrůza, PhD, Jiří Maryška, Professor, Head of Department, Technical University of Liberec The paper deals with developing of an experimental method for visualization and investigation of filtration processes on nanofibrous filtration materials. A nanofibrous textile is characterized by very high specific surface and small pore size. Thanks to this, the nanofibrous material has excellent filtration features but poor mechanical robustness and uniformity of a layer compared to the other liquid filters. The goal of the article can be divided into development of a visualization method for investigation of filtration process and into development of a quantitative method for evaluation of the local filtration efficiency in time. The visualization of filtration enables noninvasive view on the filtration process in a laser sheet. In this way the fluid flow, the manner of particle impact on a filter, des-integration of the filter and fouling of the filter layer is possible to observe. If an image analysis of the recorded images is carried out, the local filtration efficiency versus time can be determined, which is related to the filter morphology and layer uniformity. The optical method is based on determination of the local concentration of testing particles within a laser sheet. The relationship of the concentration of particles with a digital grey value of pixels in an image was theoretically described and experimentally verified. Some selected experimental results were described to show the visualization and measuring method in practice.

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Modeling Filtration Performance of Nanofiber Media Ahmed M. Saleh, PhD1, Hooman V. Tafreshi, PhD, Professor of Mechanical Engineering1 and Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute2

1Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University 2North Carolina State University This talk presents a review of our modeling activities in the areas of aerosol filtration via nanofiber media over the past decade. The presentation starts by discussing ways to produce a virtual nanofiber mat for the purpose of conducting computational fluid flow simulations and nanoparticles trajectory tracking. A detailed discussion is then given on modeling the aerodynamic slip effect which is the main attribute of nanofibers used in filtration applications leading to significant reduction in a filter’s pressure drop without affecting its particle collection efficiency. Effects of nanofiber’s cross-sectional shape as well as particle loading on filter media will be discussed in detail, and compared with the available experimental data in the literature.

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Concurrent Session: Liquid Filtration

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Ion Exchange Microfiber Nonwovens Eunkyoung Shim, PhD, Assistant Professor, TECS1, Behnam Pourdeyhimi, PhD, Associate Dean for Industry Research and Extension, William A. Klopman Distinguished Professor, Executive Director, The Nonwovens Institute1, Hannah L. Stoughtons, PhD, Senior Research Engineer2 1North Carolina State University 23M For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This study investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ion. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the micro-fiber, high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer.

51

Removal of Heavy Metals and Toxins from Contaminated Waters

Steven Zboray, Graduate Student, Sean Steadley, Graduate Student, Kirill Efimenko, PhD, Research Assistant Professor, Jiri Srogl, PhD, Adjunct Professor, Jan Genzer, PhD, Celanese Professor, Associate Department Head, Department of Chemical & Biomolecular Engineering, North Carolina State University

Recent years witnessed increased activity in the application of fundamental principles of polymer physics and polymer chemistry in helping solve pressing environmental issues using eco-friendly approaches. Optimal performance of such materials requires detailed knowledge and tunability of their chemical composition and topology.

We will describe two methodologies capable of removing toxins and heavy metals from contaminated waters. Specifically, we will introduce an effective method utilizing organic mimics of metallothioneins, high cysteine containing peptides, for removing heavy metals and toxins from contaminated waters. We will also present a simple methodology for removing heavy metals from water that utilizes commercially-available compounds, from which functional coatings are fabricated.

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Seed Strategies on the Functionality of Mineralized Nanofibers for Environmental Remediation Ericka Ford, PhD, Assistant Professor, TECS1 Yaewon Park, PhD, Research Assistant1, Preeti Rawat, Graduate Research Assistant1, Tony Blair2 1North Carolina State University 2Durham Technical Community College Water purification and protecting the environment from chemical waste is a global challenge of great importance. Nanofibers have several advantages as platforms for remediation textiles: high surface area for reaction, facile incorporation of active fillers, and the availability of low cost fillers and matrix polymer. In this talk, we describe the processing and structure of remediation nanofibers for dye contaminated water using surficial coatings of calcium carbonate (CaCO3) absorbent and photo-catalytic titanium oxide (TiO2) particles in separate instances. To achieve functional calcium carbonate nanofibers, several techniques for seeding the surface mineralization were explored; such as nanoparticles and ionic salts. CaCO3 seed crystals were dispersed in solutions of matrix polymer using surfactants and copolymers. The effect of seeding technique on the morphology and activity of CaCO3 mineralized nanofibers will be discussed. Further, we will discuss the use of TiO2 treated nanofibers in water and soil remediation.

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Nanofiber Membrane for Membrane Distillation Tomáš Jiříček1,2, Senior Researcher, Tomáš Lederer2, PhD, Michal Komárek, PhD2

1MemBrain s.r.o. 2Institute for Nanomaterials, Advanced Technologies & Innovation, Technical University of Liberec Membrane distillation is a promising separation technology, driven by a temperature difference. The largest application potential lies in desalination of concentrated solutions. Industrial use is still limited by a lack of commercially available membranes with the sufficient permeability allowing comparable performance as reverse osmosis. A porous hydrophobic membrane is the crucial element for the transport of vapor molecules through the separation membrane by a difference in partial vapor pressure. Similarly to reverse osmosis, ions are retained on the concentrate side and pure water is collected on the distillate side. The lack of proper hydrophobic membranes, providing high fluxes and high distillate purity is a reason for the presented outcomes of the research activities. Nanofiber based membranes may offer a solution to requirements of membrane distillation technology. Membranes of electrospun PVDF and PUR were tested at various conditions on a direct-contact (DCMD) unit, in order to find the optimum conditions for maximum flux. It was confirmed that thinner membranes have higher fluxes and lower distillate purity, and also higher energy losses via conduction across the membrane. As both mass and heat transfer are connected, it is best to develop new membranes with a target application in mind, for the specific membrane module and operational conditions.

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Concurrent Session: Medical II

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Cellulose Nanofiber Environments Tailored for Microorganisms and Mammalian Cells Jessica D. Schiffman, PhD, Assistant Professor, James M. Douglas Career Development Faculty Fellow, Department of Chemical Engineering, University of Massachusetts Electrospun nanofiber mats hold great promise when tailored towards specific biomedical applications, such as scaffolds for the treatment of chronic wounds and tissue engineering. Here, I will focus on highlighting our research into the nanofiber mat-microbiology interface and briefly, also introduce our recent advancements at the nanofiber mat-biology interface. Cellulose nanofiber mats hydrolyzed from electrospun cellulose acetate nanofibers serve as the “green” polysaccharide used throughout these studies because it is hydrophilic, has negative surface charges, is insoluble in water, and is commonly used in biocompatible products that interact with microbial and mammalian cells. We have systematically quantified the ability of cellulose nanofiber mats to remove both Gram-negative and Gram-positive bacteria from solutions. By surface-functionalizing the cellulose nanofiber mat platform, their ability to collect, kill, and/or be “slippery” to microbes was specifically tailored. Higher collection, lower collection, and non-fouling nanofiber mats were enabled using poly (acrylic acid) (a weak polyanion), chitosan (a weak polycation), polydiallyldimethylammonium chloride (a strong polycation), and poly(methacryloyloxyethyl phosphorylcholine) (a zwitterion). In terms of the cellulose nanofiber mats interactions with biology, our recent investigation into synthesizing hydrogel-nanofiber matrixes will also be discussed. These novel three-dimensional platforms have enabled us to properly study mammalian cell phenomena, such as, cell migration and binding. The overall goal of the talk is to illustrate our most recent findings and how these results can guide the green engineering of nanofiber-enabled biomedical materials that direct the behavior of microorganisms and mammalian cells.

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Ab Initio Design of Nanofiber-Coated Surfaces for Mitigation of Microbial Fouling Bahareh Behkam, PhD, Associate Professor, Department of Mechanical Engineering, Virginia Tech, School of Biomedical Engineering and Sciences, Virginia Tech, Macromolecules and Interfaces Institute Many taxa of microorganisms live in multicellular communities that are closely associated with surfaces. These communities known as biofilms are embedded within a polymeric matrix and their formation is of concern in medical settings as well as in industries such as oil refineries and marine engineering. Biofilm formation on medical devices is responsible for a substantial portion of healthcare associated infections causing approximately 99,000 deaths and an estimated $28-$45 billion in added healthcare costs per annum. Given the long-standing challenges of biofilm eradication, mitigation strategies based on physical and chemical surface modifications are continuously being explored. Recent works by our group and others have shown that nanoscale structural features, have wide-ranging and long-lasting effects on microorganism adhesion and biofilm development. However, a quantitative study of the effect of the geometry and size of nanostructures on microbial adhesion is lacking. In this work, we report a biophysical model of the adhesion of the model fungal pathogen, Candida albicans, on nanofiber-coated surfaces. Our theoretical model enabled quantitation of the total free energy of adherent cells in response to changes in the geometry (i.e. nanofiber diameter) and configuration (i.e. spacing) of the nanofibers. We then utilized the Spinneret-based Tunable Engineering Parameters (STEP) technique to construct nanofiber-coated polystyrene surfaces and experimentally quantified the effect of highly ordered sur- face nanostructures (200nm-2000 nm diameter nanofibers) on adhesion and proliferation of Candida albicans. The single-cell live microscopy experimental data match our theoretical predictions of the equilibrium positions of the cells for given nanofiber-coating designs. We show that a cell responds to nanofiber-texture on the surface by adjusting its geometry and relative position to minimize its total free energy. We further demonstrate that the individual adherent cell total free energy quantification enables prediction of the population-level cell attachment density (i.e. biofilm formation), which can be utilized towards ab initio design of surfaces that resist biofilm growth for medical applications and beyond. We also demonstrate a successful prototypical example of reduction in biofilm formation by optimally designed nanofiber coating of urinary catheters.

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Single Cell Mechanobiological Studies Using Aligned Fiber Networks Amrinder S. Nain, PhD, Assistant Professor, Department of Mechanical Engineering, Virginia Tech Cells receive physical and chemical cues from their surrounding microenvironment known as the extracellular matrix (ECM), a primarily fibrous network with composition and structure that varies temporally and spatially in the body. Mechanical communication between a cell and its environment occurs bi-directionally through integrin-mediated focal adhesions. Cellular environment can be mechanically described to include bulk stiffness (modulus: N/m2 independent of geometry) and structural stiffness (N/m including fiber diameter and length). While many studies have elegantly shown the role of bulk stiffness in regulating cell behavior, very few studies have explored how cells interact with fibers of different structural stiffness of varying diameters. In this regard, using our non-electrospinning Spinneret based Tunable Engineered Parameters (STEP) fiber manufacturing technique, we have recently demonstrated that suspended fibers provide cells with simultaneous 1, 2 and 3D mechanistic cues causing altered cytoskeleton response and behavior compared to 2D flat and 3D gel culture systems. We have also shown that the spatial organization of focal adhesions clusters (FAC) is curvature dependent, with cells forming FACs with longer lengths at their poles on smaller diameter fibers (~300 nm) compared to multiple FAC sites on larger diameter fibers (~800 nm) contacting the cell body. Furthermore, cells are able to precisely sense fiber diameter as evidenced by altered protrusion dynamics, with rod like protrusions on small diameter fibers (~100 nm) and sheet like on larger diameter fibers (~600 nm). We find that through curvature sensing, cells are able to modulate their forces, as measured by us using a crosshatch pattern of fibers of different diameters (250, 400 and 800 nm) fused at intersections. To understand migratory behavior, we have designed a new model comprising of aligned fiber networks bridging cell monolayers, which is able to faithfully recapitulate in vivo behavior reported using intra-vital imaging. Cells emerge from monolayers and migrate on suspended fibers by breaking cell-cell junctions at the rear. Depending upon the fiber separation distance, we observe cells to emerge as single recoils at very high emergent speeds analogous to release of a stretched rubber band or in chains of few cells. On densely spaced fibers, we observe multi-chains to emerge simultaneously as collective groups. Overall, our findings using aligned fiber networks provide new insights in fundamental cell behavior and abilities to design scaffolds for advancing biomedical research and biotechnology.

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Nanofibers for Drug Delivery Alexander L. Yarin, PhD, UIC Distinguished Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Chicago Several topics relevant in the context of drug delivery by means of electrospun nanofibers are discussed in this talk: (i) Desorption-driven release from electrospun nanofibers. The present work revealed that solidstate diffusion may not be the primary mechanism at play. In such cases the release rate of low molecular weight compounds is rather controlled by desorption of the embedded compound from nanopores in the fibers, or from the outer surface of the fibers. This is demonstrated using a model compound, a fluorescent dye. In addition, the desorption-limited release mechanism is supported by the results for release of two model protein (high molecular weight) compounds: bovine serum albumin (BSA) and an anti-integrin antibody (AI). The results are consistent with protein release mechanism dominated by desorption from the polymer surface. Moreover, the desorption-driven mechanism of drug release from nanofibers can be in the interplay with porogen leaching. Such compound mechanisms of drug release are important to achieve a sustainable release of hydrophilic drugs, like ciprofloxacin hydrochloride (CIP). The experimental results on the desorption-driven drug release are also corroborated by the theory developed in the present work. (ii) The rate of drug release can be controlled by nanofibers containing thermos- and pH-responsive hydrogels, which is also demonstrated in the present work. (iii) Nanochannels formed with the help of sacrificial electrospun nanofibers were also used to polymerize sufficiently monodisperse monolithic and core-shell thermo-responsive Poly(N-isopropyl acrylamide)(PNIPAM) nanoparticles of the order of 400 nm dia. at the rate of 107 particlesper sec. During their formation, the nanoparticles were loaded with a model fluorescent admixture to study its encapsulation in these promising drug carriers. The release kinetics from the nanoparticles was studied under the conditions of thermal stimulation.

59

Concurrent Session: Medical III

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Applicability of Silica Nanofibres in Medicine and Biotechnology Irena Lovětinská Šlamborová, PhD, Assistant Professor1, Petr Exnar, Associate Professor2, Iveta Danilová, Textile Faculty1, I. Veverková1

1Institute of Health Studies, Technical University of Liberec

2Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec In recent years, the properties of inorganic nanomaterials are intensively studied in comparison with widely used organic nanomaterials. Pure silica nanofibers are convenient for medical applications because they are able to satisfy a number of very stringent criteria, such as low toxicity, biodegradability or relatively high porosity. On the surface of silica nanofibers, there are formed Si–OH bonds. Due to this fact, this nanomaterial is a very attractive matrix for binding and a controlled release of biomolecules. The presented research is focused on physical and chemical properties and functionalization of silica nanofibers contributing to potential applications of the nanomaterial in medicine and biotechnology, specifically in regenerative medicine.

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Nanofibers as a Dry Form of Drug-Loaded Nanoparticles for Long-Term Storage Shani L. Levit, Graduate Student and Christina Tang, PhD, Assistant Professor, Department of Chemical and Life Science Engineering, Virginia Commonwealth University Encapsulating drugs in nanoparticles can provide many benefits such as increasing delivered drug concentration while reducing side effects. However, stability and transportation in solution remain challenging. As an alternative to current freeze drying methods which often result in particle aggregation, processing the nanoparticles into dry nanofiber form in proposed. In this study, we electrospun blends of drug-loaded, polymer stabilized nanoparticles with water-soluble polymers as a method for long-term storage. During electrospinning, a high electric field is applied to the extruded polymer solution forming fibers that are ultimately deposited as a nonwoven containing nanoparticles. The nanoparticles were then reconstituted by dissolving the fibers in water; the nanoparticle size was analyzed and compared to initial size. Several polymer systems have been tested to determine the effect of fiber diameter on final nanoparticle size. When using polyvinyl alcohol (PVA), the nanoparticles could be reconstituted to within 20% of their original size when fibers were the same size as the nanoparticles (ratio = .96). Using β-cyclodextrin (CD) and PVA, nanoparticles could be reconstituted to within 5% of their original size (ratio = 0.14). We attribute the difference in the results to the increased shear forces that result when electrospinning macromolecules (PVA) compared to small molecules (CD). Electrospinning nanoparticles with polymers is a promising method for converting nanoparticles to a dry form and reconstituting them to within 5% of the initial size. Using electrospinnable polymers currently approved for paternal use are currently under investigation.

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Concurrent Session: Analytical & Characterization of Nano Materials

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Visualizing Interfacial Phenomena in Bio-Derived Fiber Reinforced Composites Chelsea S. Davis, PhD, NRC Postdoctoral Fellow1, Jeremiah W. Woodcock, PhD, Research Chemist1, Muzhou Wang, PhD, NRC Postdoctoral Fellow1, Ryan Beams, PhD, Postdoctoral Fellow2, Stephan Stranick, PhD, Chemist2, Aaron M. Forster, PhD, Materials Research Engineer2, Jeffrey W. Gilman, PhD, Polymer Chemist1

1Materials Science and Engineering Division, National Institute of Standards and Technology 2Materials Measurement Science Division, National Institute of Standards and Technology In fundamental composite theory, the nature of the interface is a key parameter in determining the mechanical performance and fracture behavior of the overall composite. Here, we investigate the nature of the interface of fiber-reinforced polymer composites (FRPC). Work has been performed to image the interfacial debonding of a single fiber silk/epoxy composite. Our approach has been to utilize a mechanically activated dye molecule covalently bound across the interface. Taking advantage of the amine-containing amino acid repeat units (namely arginine and lysine) present in low concentrations in the amorphous regions of a silk fiber’s surface, we have covalently attached a commercially available rhodamine dye. A polyetheramine/bisphenol A epoxy matrix is crosslinked around the functionalized silk, forming covalent bonds between the epoxide groups of the matrix and the unbound end of the rhodamine. Utilizing time correlated single photon counting (TCSPC) techniques, the local environment of the mechanophore (bound across the interface versus attached only to the epoxy or silk) can be determined through fluorescence lifetime imaging microscopy (FLIM). Initial results have shown that our rhodamine-based mechanophore can be used to observe interfacial fracture and local stress concentrations before macroscopic failure is observed. This mechanophore/mechanical deformation approach allows an optical microscope to probe local interfacial features in a powerful way, enabling characterization of natural materials that will complement measurements made by standard mechanical testing methods.

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Measuring Temperature at the Mesoscale with Optical Approaches Laura I. Clarke, PhD, Professor, Department of Physics, North Carolina State University

There are many applications in which steady state internal temperature, within a fiber, nanofiber, or bulk material, is inhomogeneous. In polymer nanocomposites, for instance, photothermal heating or other particle-based techniques that produce heat at the particle result in significant temperature gradients with the material. Over the last several years, we have utilized optical techniques, primarily based on ratio-metric fluorescence measurements of small dyes homogeneously dispersed within the polymer, to determine temperature at different length scales. These approaches transition almost seamlessly from bulk to nanofibers and thus are useful tools to characterize and understand heat transport in nanofibers.

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Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) Analysis: From Fibers to Forensics Chuanzhen Zhou, PhD, Research Scholar1, Fred A. Stevie, Senior Researcher, Lab Manager1 and David Hinks, PhD, Dean, College of Textiles, Cone Mills Professor of Textile Chemistry2

1Analytical Instrumentation Facility, North Carolina State University 2Department of Textile Engineering, Chemistry and Science, College of Textiles, North Carolina State University Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is a highly sensitive direct surface analytical technique, producing mass spectra and mass spectral images from the outer 1 to 2nm of materials, and thus is capable of providing detailed information about the molecular structure of surfaces. Direct imaging of ToF-SIMS provides spatial distribution of both organic and inorganic species to yield surface reactivity maps. North Carolina State University (NCSU) has the largest College of Textiles in the United States and the second largest in the world. Recent research has covered many interesting topics, such as surface modification of textile fibers and dyes in fiber trace evidence. ToF-SIMS has been demonstrated to be a very powerful analytical method for analysis of textiles because it has the sensitivity to reveal chemical composition and spatial distribution on modified textile fibers. Examples will be presented that include identification of dyes in fibers, fluorine in polymer treated cotton fabrics, additives in sheath/core fibers, and identification of synthetic dyes. The nature of woven and non-woven fabrics presents major challenges with regard to TOF-SIMS sample preparation. Methods used to obtain and optimize analyzable surfaces will also be discussed.

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Application of X-Ray Diffraction Methods to Textile Materials Ching-Chang Chung, PhD, Postdoctoral Research Scholar, Department of Materials Science and Engineering, North Carolina State University and Analytical Instrumentation Facility, North Carolina State University X-ray diffraction (XRD) is one of most important characterization techniques for the analysis of nanofibers and other nano-materials due to the wavelength of X-rays is on the atomic scale. XRD analysis could provide useful structural information, and structural properties of these materials are critical importance to the performance of their mechanical and thermal properties. Among the XRD characterization methods, two methods, 2D wide-angle diffraction (2D XRD) and azimuthal scan, are significantly useful for the determination of molecular structure, crystallite size, crystallinity, and degree of fiber alignment in textile and polymeric materials. Investigation of the structural properties of different materials using various XRD analysis methods will be highlighted in the presentation. Few examples will be discussed include identification of crystalline phase in polyester fiber, evaluation of crystallinity in nylon-6 filament using diffraction peak fitting method, estimation of crystallite size in poly(ε-caprolactone) (PCL) nanofibers using Scherrer equation, and analysis of degree of fiber alignment in Fe2O3 nanoparticles blended polyvinyl alcohol (PVA) fibers and cellulose fibers using Herman's orientation factor. The correlation of the structure and their physical properties will also be examined. Combining XRD analysis with other characterization techniques such as thermal analysis, rheology, mechanical testing has been shown to be helpful in understanding the structure-property relationship in textile materials.

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Mechanical Measurements and Microscopy as Characterization Tools for Nanofibrous Webs Russell E. Gorga, PhD, Associate Professor, TECS, Program in Fiber and Polymer Science, North Carolina State University Mechanical and microscopy techniques to characterize nanofibrous webs are the focus of this paper. Optical and electron microscopy techniques to characterize fiber quality (average fiber diameter, diameter distribution, and homogeneity) are specifically addressed. Atomic force microscopy is used to characterize crystalline structure and orientation. Mechanical techniques to characterize web modulus, strength and ductility are also discussed. Finally, for nanofibrous webs filled with nanoparticles, microscopy is used characterize particle distribution and concentration.

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Long-Term Evaluation of Selected SPME Fibres – Implications for Polychlorinated Biphenyls Analysis

Vojtěch Antoš, Pavel Hrabák, PhD, Michal Komárek, PhD, Martin Stuchlík, Technical University of Liberec Polydimethylsiloxane represents a gold standard among polymers for analytical utilization in chromatography. Aside of the capillary column stationary phase, polydimethylsiloxane (PDMS) is employed as a sorbent for solid phase microextraction (SPME), which is one of the most convenient and green techniques for sample introduction into gas chromatographs (GC). In our experience, PDMS fibre of 100 µm thickness represents a mature and robust product for determination of semivolatile compounds including PCBs. Therefore, we conducted a study of long-term fibre stability with 100 µm thick commercial PDMS fibre as a reference. Two other lab-made SPME fibres were included: polyetherimide (PEI) in a form of coating and in a form of nanofibres assembly. Several hundreds of repeated headspace GC-MS injections were conducted with each of the fibres. GC-MS system responses were gathered for each 50th injection together with microscopic image of the fibre appearance. A promising stability of system response was found for PEI fibres, although it doesn’t reach that of PDMS fibre. According to our results, the concept of lab-making of SPME fibres seems to be a viable alternative for green analytical chemistry.

69

Concurrent Session: Nanoscale Functionalization

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Supramolecular Nonwovens: Designing Nanofibrous Constructs from the Ground-Up Richard J. Spontak, PhD, Professor1,2, Kenneth P. Mineart, PhD, NRC Post-doctoral Fellow4, Daniel P. Armstrong, Graduate Student1, David J. Lunn, PhD, Postdoctoral Fellow5, Oliver E. C. Gould, Research Associate3, Paul G. Pringle, PhD, Professor3 and Ian Manners, PhD, Professor3

1Chemical and Biomolecular Engineering, North Carolina State University 2Materials Science and Engineering, North Carolina State University 3Chemistry, University of Bristol 4National Institute of Standards and Technology 5Bayley Group, Chemical Biology, Department of Chemistry, University of Oxford

Crystallization-driven self-assembly is a newly identified mechanism by which crystallizable block copolymers are capable of forming micron-long core-shell nanofibers, rather than conventional interface-minimizing nanostructures, in a selective solvent. The length of these "comicelle" nanofibers can be precisely controlled in much the same way as macromolecular chains during living polymerization. Insertion of a phosphine moiety into the nanofiber shell permits coordination-driven coupling of these nanofibers to generate supramolecular nonwovens. In this study, we examine various chemical considerations regarding nanofiber growth and employ transmission electron microscopy/microtomography (TEM/TEMT), along with nanoindentation, to examine the morphological and mechanical properties of nonwoven constructs generated from the nanofibers. In addition, we explore copolymers that are likewise able to self-assemble into more complex shapes, such as nanotoroids.

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Generation of Functional Coatings on Hydrophobic Surfaces through Deposition of Denatured Proteins Followed by Grafting from Polymerization Kiran Goli, PhD, Graduate Research Assistant1, Orlando Rojas, PhD, Professor of Forest Biomaterials and Chemical and Biological Engineering2, Jan Genzer, PhD, Celanese Professor, Associate Department Head3

1Department of Materials Science & Engineering, North Carolina State University 2Department of Forrest Biomaterials, North Carolina State University 3Department of Chemical & Biomolecular Engineering, North Carolina State University

Hydrophilic coatings were produced on synthetic polypropylene (PP) nonwoven surfaces through the adsorption of denatured proteins. Specifically, physisorption from aqueous solutions of α-lactalbumin, lysozyme, fibrinogen, and two soy globulin proteins (glycinin and β- conglycinin) after chemical (urea) and thermal denaturation endowed the hydrophobic surfaces with amino- and hydroxyl- functionalities yielding enhanced wettability. Proteins adsorbed strongly onto PP through hydrophobic interactions. The thickness of adsorbed heat-denatured proteins was adjusted by varying the pH, protein concentration in solution and adsorption time. In addition, the stability of the immobilized protein layer was improved significantly after interfacial cross-linking with glutaraldehyde in the presence of sodium borohydride. The amino and hydroxyl groups present on the protein-modified surfaces served as reactive sites to attach polymerization initiators, from which poly(2-hydroxyethyl methacrylate) (PHEMA) brushes were grown. The terminal hydroxyls of HEMA’s pendent groups are modified with fluorinating moieties of different chain lengths resulting in amphiphilic brushes. Anti-fouling properties of the resultant amphiphilic coatings on PP are analyzed by following the adsorption of fluorescein isothiocyanate-labeled bovine serum albumin as a model fouling protein.

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Surface Treatment of Nanofiber Media for Improved Hydrophobicity and Oleophobicity Fred Humiston, Director of Business Development, Sigma Labs Nanofiber media are increasingly used in challenging air filtration and other filtration applications, some of which involve oily mists and/or particulates that can degrade media performance. Applying a durable oleophobic surface treatment to this media without compromising filtration performance may provide benefits such as extended filter life. Sigma Technologies has pioneered a high-throughput, no heat, water- and solvent-free technique for applying functional surface treatments to nanofibers and other porous media. The presentation will provide an overview of the treatment process and show results from trial runs with various nanofiber materials.

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Antimicrobial Three Dimensional Woven Filters Containing Silver Nanoparticle Doped Nanofibers in a Membrane Bioreactor for Wastewater Treatment Fang Zhao3, Chen Si3, Qiaole Hu3, Gang Xue4, Qingqing Ni, PhD, Academic Assembly Professor5, Qiuran Jiang, PhD, Associate Professor123,Yiping Qiu, PhD, University Titled Professor123

1Key Laboratory of Textile Science &Technology, Ministry of Education, College of Textiles, Donghua University 2Shanghai Key Laboratory of Advanced Micro &Nano Textile Materials, College of Textiles, Donghua University 3Department of Technical Textiles, College of Textiles, Donghua University 4College of Environmental Science and Engineering, Donghua University 5Department of Functional Machinery and Mechanics, Shinshu University

Antimicrobial three dimensional (3D) woven fabric filters are fabricated by wrapping the weft yarn with electrospun nanofibers containing 2 wt. % silver nanoparticles (AgNPs). For comparison, 3D fabrics with the same structure composed of commercial antimicrobial yarns containing Ag ion and control yarns of the same types are also fabricated. The disk diffusion test shows that the fabric and the yarns with AgNPs nanofibers and Ag ions suppress the growth of bacterial colonies. A long term filtration performance test show that the fabric filter containing AgNPs has 40 – 50% higher fluxes and substantially larger flux recovery proportions than those of the corresponding control filter. The scanning electron microscopy and confocal laser scanning microscopy analyses show that the fabric filter with AgNPs nanofibers has the lowest bacterial cell, polysaccharides, and protein clusters on surface and inside the first two layers of the fabric filters. This is achieved with a concentration of antimicrobial agent two orders of magnitude lower than a regular commercial antimicrobial filter, showing the efficiency of using antimicrobial nanofibers in a fabric filter.

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Concurrent Session: Electrospinning

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Advances in Electrospun Nanofiber Forming Technology in China Yanbo Liu, PhD, Professor/Senior Engineer1,2, Qian Ren1, Samman H. Bukhari1, Wenxiu Yang2, Ligai Zhang2, Kaiqiang Liu2, Hong Cao2

1School of Textile Science and Engineering, Wuhan Textile University 2School of Textiles, Tianjin Polytechnic University As an effective nanofiber forming avenue, electrospinning technology has developed rapidly in China in recent years with the advances in nanomaterials science and technology, which has great potentials in the application fields like filtration media of gases and liquids, lithium ion battery separators, wound dressing, controlled drug release, tissue engineering, protective clothing, architecture protective membrane etc. Electrospinning technologies based on different mechanisms such as multineedle, liquid self-organization on free surface, ultrasound and bubble electrospinning are currently in the phase of industrialization after overcoming the relevant technical obstacles. In this paper, the important development in the electrospinning technology of China, mainly including the research on improvement of electric field distribution, large-scale electrospinning technology and investigation on applications of nanofibrous products are briefly introduced to favor the fast advancement of electrospinning technology, the industrial manufacture and commercial utilization of electrospun nanofibers worldwide.

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Electrospray/Electrospinning of 3D Si/C Fiber Paper Electrodes Chunsheng Wang, PhD, Professor, Department of Chemical & Biomolecular Engineering, University of Maryland Although the theoretical capacity of silicon is ten times higher than that of graphite, the overall electrode capacity of Si anodes is still low due to the low Si loading and heavy metal current collector. Here, a novel flexible 3D Si/C fiber paper electrode synthesized by simultaneously electrospraying nano-Si-PAN (polyacrylonitrile) clusters and electrospinning PAN fibers followed by carbonization is reported. The combined technology allows uniform incorporation of Si nanoparticles into a carbon textile matrix to form a nano-Si/carbon composite fiber paper. The flexible 3D Si/C fiber paper electrode demonstrate a very high overall capacity of ≈1600 mAh g−1 with capacity loss less than 0.079% per cycle for 600 cycles and excellent rate capability. The exceptional performance is attributed to the unique architecture of the flexible 3D Si/C fiber paper, i.e., the resilient and conductive carbon fiber network matrix, carbon-coated Si nanoparticle clusters, strong adhesion between carbon fibers and Si nanoparticle clusters, and uniform distribution of Si/C clusters in the carbon fiber frame. The scalable and facile synthesis method, good mechanical properties, and excellent electrochemical performance at a high Si loading make the flexible 3D Si/C fiber paper batteries extremely attractive for plug-in electric vehicles, flexible electronics, space exploration, and military applications.

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Concurrent Session: Novel Applications

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Functional Nanofibers via Electrospinning: Approaches to Tailoring Drug Release Nancy Burns, Graduate Student, Alexandra Brozena, PhD, Postdoctoral Student, Gregory Parsons, PhD, PI, Alcoa Professor, and Saad Khan, PhD, Alcoa Professor, Director of the Graduate Program, Chemical and Biomolecular Engineering, North Carolina State University The use of electrospun nanofibers presents an exciting opportunity for the development of materials with novel and functional performance. Such desirable attributes stem in part from the intrinsic dimensional characteristics of nanofibers: high surface to volume ratio and ability to embed or coat functional moieties onto the fibers. Of interest to us is its use in biomedical therapeutics including wound healing, tissue engineering, and drug delivery devices. In this study, we focus on examining two different strategies that can be applied to the same drug loaded nanofibers system to create either a rapid or extended drug release profile. These include (1) complexation of a poorly water soluble drug and (2) coating the nanofiber surface. The first approach uses cyclodextrin, an inclusion compound, to complex a poorly water soluble drug, ketoprofen. Complexation of the drug within cyclodextrin was found to increase drug loading by sevenfold while tuning the dissolution rate of the nanofibers by over two orders of magnitude. The second approach entails extending the mat dissolution times and drug release profiles by coating the nanofiber surface using atomic layer deposition (ALD). The extent of drug release was found to depend on the thickness of the ALD coating and could be used to extend release from minutes to weeks by limiting the diffusion from the nanofiber. We discuss the underlying mechanisms of the two approaches and their potential as drug delivery platforms

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Fighting Infections via Engineered Nanofibers Mahsa Mohiti-Asli, PhD, Research Assistant Professor, Biomedical Engineering, North Carolina State University Engineered fibrous scaffolds have emerged as a favorable platform technology for wound healing and tissue engineering applications. Fibrous materials can be constructed from biocompatible, biodegradable materials that possess structural and physical similarities to the native extracellular matrix. In addition to mimicking the in vivo topographical environment, fibrous materials provide an ideal substrate for bioactive molecule delivery based on their superior surface area to volume ratio (yielding maximum interaction with a surrounding medium), and the ability to generate controlled release kinetics based on biomolecule placement within the fibrous scaffold. We have developed polylactic acid nanofibers with novel fiber morphology for controlled delivery of silver ions to infected wounds. Results have shown that the newly developed antimicrobial nanofibers kill and inhibit growth of multi drug resistant (MDR) bacteria and promote skin regeneration in a scarless fashion. These antimicrobial dressings will provide great clinical benefit to all patients with infected wounds when traditional antibiotic therapies are not adequate for addressing MDR bacteria.

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PHBV Fibres for Replacement Tendons and Ligaments Tom O’Haire, Research Fellow2 Stephen J. Russell, PhD, Chair of Textile Materials and Technology; Professorial Representative; Group Leader: Textile Materials2, Sarah Upson, PhD, Postdoctoral Research Associate1, Kenneth Delgarno, PhD, Sir James Woodeson Professor of Manufacturing Engineering1 and Ana Ferreira-Duarte, PhD, Lecturer1

1School of Mechanical and Systems Engineering, University of Newcastle 2School of Design, University of Leeds The mechanical and biocompatibility requirements for ligament and tendon regenerative scaffolds are sufficiently demanding as to limit the number of polymers suitable for this application. This presentation concerns the production of 100% Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microfibres using solution centrifugal spinning operating with a radial collection system. The resulting fibrous PHBV network is intended to be implanted to enable restoration of mechanical function in the damaged connective tissues. A parameter study was conducted with the variables of concentration, rotational speed and collection distance. Ultrafine nonwoven webs produced from such a system which were found to have a Young’s modulus of 98 MPa with a strain at break as low as 3.6%. The directional strength, stiffness and point of strain at break of the PHBV webs was found to be correlated to the rotational speed of the spinneret. The capacity for the engineering of centrifugal webs through process various will be linked to the observed fibre orientation. The potential for such materials in a biomechanical scaffolding device will also be discussed. The mechanical property requirements of the implant, together with the mode of fixation and implantation during surgery is also covered.

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Nanofiber-Based Colorimetric Biosensing Breland T. Edwards, Research and Development Team1, Anjali Nanjannavar, Undergraduate Researcher2 and Christina Tang, PhD, Assistant Professor2 1WestRock Company 2Department of Chemical and Life Science Engineering, Virginia Commonwealth University Biosensors enable selective detection of an analyte of interest. Coupling the bio-recognition component with nanofibers can enable fast and sensitive detection to the high specific surface area. Using color change as a means of detection would enable simple and portable point-of-use detection. Such nanofiber-based colorimetric detection can achieved by coupling biomolecules with polyaniline. Results with applications in food safety, environmental monitoring and smart fabrics will be discussed.

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Tailored Wettability in Electrospun Fibers Mackenzie Geiger, Graduate Tech. & Research Assistant, and Saad Khan, PhD, Alcoa Professor, Director of the Graduate Program, North Carolina State University Fumed silica (FS) particles with hydrophobic (R805) or hydrophilic (A150) surface functionalities are incorporated in polyacrylonitrile (PAN) fibers by electrospinning to produce mats with controlled wettability. Rheological measurements are conducted to elucidate the particle-polymer interactions and characterize the system while microscopic and analytic tools are used to examine FS location within both fibers and films to aid in the fundamental understanding of wetting behavior. Unlike traditional polymers, we find these systems to be gel-like, yet electrospinnable; the fumed silica networks break down into smaller aggregates during the electrospinning process and disperse both within and on the surface of the fibers. Composite nanofiber mats containing R805 FS exhibit an apparent contact angle over 130o and remain hydrophobic over 30 minutes, while similar mats with A150 display rapid surface-wetting. Wicking experiments reveal that the water absorption properties can be further manipulated, with R805 FS-impregnated mats taking up only 8% water relative to mat weight in 15 minutes. In contrast, PAN fibers containing A150 FS absorb 425% of water in the same period, even more than the pure PAN fiber (371%). The vastly different responses to water demonstrate the versatility of FS in surface modification, especially for sub-micron fibrous mats. As a model platform for fumedsilica containing composites, we have expanded our research to explore characteristics beyond that of solely wetting behavior.

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Large-Scale Production of Polymer Nanofiber Nonwovens for Applications in Li-Ion Battery, and Air and Liquid Fine Filtration Haibo Xu, Songzhi Zhou, Linlin Chen and Haoqing Hou, Department of Chemistry and Chemical Engineering, Jiangxi Normal University Elctrospun nanofibers has been attracting worldwide intensive attention due to (1) its small diameter and high specific area; (2) the highly porous nanofiber nonwovens; (3) particularly, being made in an easy way. The highly porous nonwovens are being used or finding uses in separator for lithium battery, filtrations among others. Future applications of nanofibers may include solar sails, light sails and mirrors in space. For the above applications, electrospun nanofiber nonwovens should have good mechanical properties in order to meet the winding tension in a mechanized production process and should be able to be produced in an industrial scale for a commercial market. To date, the electrospun nanofiber nonwovens or self-supporting electrospun nanofiber mats have, however, not been produced in a large scale. Three factors, stress of the electrospun nanofibers, reinforcement of the as-produced nonwovens via adhesion between the nanofibers, and re-dissolution of the as-produced nanofibers by the solvent vapor generated in the mass production process, may be the main reasons that retard the development of the electrospun nanofiber nonwovens. In this presentation, we introduce a way to the mass production of electrospun polyimide nanofiber nonwovens by using needled electrospinning nozzle array modules. The production speed of nanofiber nonwovens directly depends on the number of used modules. A production line with 30 such modules could produce 2-3 m2 nanofiber nonwovens with a surface density of 10-15 g/m2 per minute. The as-produced nanofiber products could be thermally treated to form the nanofiber nonwovens with an as-desired porosity or density for the battery separator application, and for air purification and liquid filtration applications. For the moment, the technology level is, however, very primitive or backward. We hope to find partners to develop corresponding modern equipment and to promote a commercially production of self-supporting nanofiber nonwovens for the benefit of our humanity.