Electrospinning of nanofiber

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  1. 1. ELECTROSPINNING OF NANOFIBERS Presented by: PREM KUMAR SR 4NI11ME088
  2. 2. OUTLINE: Introduction Background Apparatus Working principle Variables Fiber alignment Applications Future Research Reference
  3. 3. Introduction Nanofibers are created by a process called electrospinning. Electrospinning is a major way to engineer (without self- assembly) nanostructures that vary in: Fiber Diameter Mesh Size Porosity Texture Pattern Formation Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006. http://en.wikipedia.org/wiki/File:Taylor_cone_photo.jpg
  4. 4. An Example Take the distance between the Earth and the Moon, L, to be 384,400 km. It takes only x grams of a polymer fiber filament to make up this distance = 1 g cm-3 and the fiber diameter d = 2r = 100 nm X = V = r2L = (50 nm)2 (380,000 km) (1 g cm-3 ) 3 grams Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.
  5. 5. Electrospinning
  6. 6. Schematic Representation of the Reactive Electrospinning Apparatus Fibers are irradiated with UV light during spinning in order to form crosslinked graft scaffolds
  7. 7. Electrospinning - Procedure An electrostatic potential is applied between a spinneret and a collector A fluid is slowly pumped through the spinneret. The fluid is usually a solution where the solvent can evaporate during the spinning. The droplet is held by its own surface tension at the spinneret tip, until it gets electrostatically charged. The polymer fluid assumes a conical shape (Taylor cone). When the surface tension of the fluid is overcome, the droplet becomes unstable, and a liquid jet is ejected Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.
  8. 8. Electrospinning Polymers The small size between the fibers allows the capture of particles in the 100- to 300- nanometer range That is the same size of viruses and bacteria Used as air-filter: Airplanes, office, etc. Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006. Polymer Solvent Concentration Potential Application Nylon 6,6 Formic Acid 10 wt% Protective Clothing Polyurethanes Dimethylformamide 10 wt% Protective Clothing Polycarbonate Dichloromethane 15 wt% Sensor, Filter Polylactic Acid Dichloromethane 14 wt% Drug Delivery System
  9. 9. Nanofibers have large surface area per gram
  10. 10. Electrospinning Variables Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.
  11. 11. Fibre alignment A cylinder collector with high rotating speed A thin wheel with sharp edge An auxiliary electrode/electrical field
  12. 12. Applications Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.
  13. 13. Improvements and Further Research Develop more precise electrospinning techniques Mechanisms of electrospinning Growth rates Bending Instability Producing nanofabrics with specific mechanical properties. Creating 3-dimensional shapes Capable of being used in controlled release of drugs. Burger, Christian, et. al. Nanofibrous Materials and Their Applications. 2006.
  14. 14. Improvements and Further Research Optimization of parameters Intrinsic properties of solution Polarity, surface tension of solvent, MW of polymer, etc. Safety Solvents Dangerous to health and environment "Electrospin Nanofibers for Neural Tissue Engineering." http://www.rsc.org/ejga/NR/2010/b9nr00243j-ga.gif
  15. 15. References [1] Abdel-Ghani MS, Davies GA. Simulation of non-woven fibre mats and the application to coalesces. Chemical Engineering Science 1985; 40(1):11729. [2] Adanur S, Liao T. Computer imulation of mechanical properties of nonwoven geotextiles in soil-fabric interaction. Textile Res J 1998; 68:15562. [3] Angadjivand SA, Schwartz MG, Eitzman PD, Jones ME. US patent, 6375886. 2002. [4] Athreya SA, Martin DC. Impedance spectroscopy of protein polymer modified silicon micromachined probes. Sensors and Actuators aPhysical 1999; 72(3):20316. [5] Bognitzki M, Czado W, Frese T, Schaper A, Hellwig M, Steinhart M, et al. Nanostructured fibres via electrospinning. Adv Mater 2001; 13:702. [6] Demir MM, Yilgor I, Yilgor E, Erman B. Electrospinning of polyurethane fibres. Polymer 2002; 43:33039.