Soft Matter World NewsletterMarch | 2011 | Issue 27

Dear Soft Matter Colleagues, This month we are featuring a brand new group from a University that was just added to the map! Next month we will be publishing a Noticeboard Bulletin. If you have any open positions that you would like advertised be sure to send them to the editor this month so they can be published and sent out in the Bulletin for April.

The picoForce Lab is based out of Georgia Tech University and led by Dr. Elisa Riedo. Her research fo-cuses on the interaction forces at solid/liquid interfaces. These forces include but are not limited to fric-tion forces, van der Waals forces, hydrophobic forces, capillary forces and bond forces. While these forces may seem in-tuitive and obvious at larger length scales there remains alot to be un-derstood on the molecular and sub-molecular scales, a field commonly known as tribology. An improved understanding of the mechanical, and tribological properties appear-ing at the nano-length scale has

far reaching applications in many all the facets of nano-technology research. Furthermore, it spans outside of the realms of just nano-technology. Consider an example in biology; understanding the me-chanical behavior of nanotubu-lus such as acquaporine and DNA strands is crucial to comprehend the structural dynamics of cellular processes. Dr. Riedo uses Atomic Force Microscopy (AFM) extensively to gather data on these micro length scales. Two if the most notable methods are Modulated Nanoin-denting & Thermochemical Nano-lithography. Modulated nanoindenting uses AFM to measure the mechanical properties of nano-objects, namely oxide nanosprings, nanobelts and nanorings. Nanoindenting employs the use of AFM tips to “push” or “roll” nanotubes and wires along different surfaces. This process al-lows measurement the nanoscopic contact friction area which charac-terizes the intrinsic friction prop-erties of a material. The under-standing of elasticity and friction anisotropy on a nano length scale

opens new doors to understanding the atomistic origin of friction forc-es. Thermochemical Nanolithogra-phy, employs a resistively heated AFM cantilever to induce well de-fined chemical reactions in order to change surface functionality of thin polymer films. One of the group’s latest projects involved tuning the topographical and electrical prop-erties of reduced graphene oxide

(top) Topography image of a CNT of 7nm radius. The fast scanning direction of the AFM-tip is indicated by an arrow. (bottom) Topog-raphy of a cross shape of reduced graphene oxide formed after an AFM tip heats the con-tact to 330°C scanned across the GO sheet at 2 mm/s.

Nano-scale Interaction Forces Laboratory:PicoForce at Georgia Tech

Scanning Electron Microscopy (SEM) im-age of a ZnO nanowire array grown on sap-phire surface. (inset) Topography image of the aligned ZnO nanowire arrays received in AFM contacting mode.

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Soft Matter World Newsletter

(rGO) with nanoscopic resolution via a heated AFM tip. Some of the other current and fu-ture research interests of the group include:

• Nano Mechanical proper-

ties of Organic Semiconduc-tors Interfaces

• Long and Short Range Hy-drophobic Forces

There are currently two gradu-ate student positions openings the

group. Visit the picoForce website to read more.

http://phweb.physics.gatech.edu/re-search/riedo//

Self-assembly of Anisotropic ParticlesSz i lard N. Fe jer, Dwaipayan Chakrabar t ia and Dav id J . Wales . Sof t

Matter 2011. DOI : 10 .1039/c0sm01289k

(left) Simulation of global minima for small clusters composed of discoids interacting via the Paramonov-Yaliraki (PY) potential. (middle) Simulation of Global minima of clusters assembled from discoids inter-acting via a modification of the PY potential decorated with additional Lennard-Jones (LJ) repulsive sites, indicated in blue. (right) Global min-ima of clusters assembled from discoids interacting via the Gay-Berne (GB) potential.

Researchers discuss the main features of the poten-tial energy landscapes that are associated with efficient ‘structure-seeking’ systems for particles interacting via anisotropic, pairwise additive forces. The authors state that while it is a relatively straightforward task to synthesize molecules and objects on the macroscopic scale it remains difficult to create well-defined three-dimensional structures between the atomic and micro-scopic length scales because it requires machinery of a similar size. The interparticle potentials employed in this paper are intended for a coarse-grained description of meso-scopic building blocks, such as colloids or functional-ized metal clusters. It is shown that the anisotropy of the building blocks and the orientation-dependent in-teraction strengths are the most important factors that govern self-assembly into particular target morpholo-gies. Design principles are outlined and discussed for various structures throughout the paper. To read more visit RSC Publishing.

Researchers from Ja-pan present a method to control membrane phase separation through the action of a synthetic pho-toresponsive amphiphi-les. Multi-component gi-ant vesicles were formed from a ternary lipid mix-ture of saturated and un-saturated phospholipids and cholesterol together with the photoresponsive amphiphile. By inducing

a change in the confor-mation of the amphiphile the auhtors were able to switch membrane lateral segregation in a revers-ible manner. Cis-isom-erization induced lateral phase separation in one phase membranes while two-phase membranes produced additional lat-eral domains. Membranes that were close to the miscibility boundary dem-

onstrated high photo-re-sponsiveness. This is the first report on the reversible control of membrane lateral seg-regation triggered by a conformational change in a membrane-constituting molecule. These findings may lead to new methods for controlling membrane self-organization. To read more visit RSC publishing.

Photochemical control of membrane raft organizationT. Hamada, R . Sug imoto ,T. Nagasak ib and M. Takag i . Sof t Matter 2011, 7 , 220–224. DOI : 10 .1039/

c0sm00797h

Fluorescence photo-micro-graphs of photo-induced re-versible organization of lateral domains in one-phase bilayer membranes. Below is a schemat-ic representation of the molecu-lar switching.

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The Freiburg Institute for Ad-vanced Studies (FRIAS) is the Uni-versity of Freiburg’s international research college. This workshop, hosted by the FRIAS Center for Soft Matter Research, invites research-ers working on experiment, theory and computer simulation in differ-ent fields relevant for the self-as-sembly process. It is being held in the heart of the stunning Black For-est in Germany on May 25-27. The fields range from self-as-sembly processes in biology, such as the folding of proteins into 3D structures and the self-assembly of DNA molecules, synthesis of artifi-

cial units, growth of colloidal crys-tals (with emphasis on anisotropic particles), to packaging in nano- and microelectromechanical sys-tems. All speakers, by invitation only, are internationally recognized ex-perts in their research areas. The workshop will also feature an eve-ning poster session where work-shop attendees can present and informally discuss their research re-sults. The registration deadline is April 25, 2011. Visit the website to read more and register. Don’t miss out on an opportunity to attend an ex-

cting workshop in a stunning loca-tion. Visit the website to read more.

Black Forest Focus on Soft Matter 5: Self Assembly on all Scales

Soft Matter Science: Concepts for the Design of Functional Mate-rials, is a new graduate school col-laboration between France (Stras-bourg and Mulhouse), Germany (Freiburg) and Switzerland (Basel). The International Research Train-ing Group brings together chem-ists, physicists, biologists and en-gineers from Freiburg, Strasbourg, Mulhouse and Basel to establish a new PhD program in soft matter sci-ence. Currently they are hosting two

important events:

Challenges in and Potential of Polymer Physics

This discussion meeting is being held May 4-6 2011 in Schluchsee, Germany. The aim of the workshop is to discuss current challenges in polymer physics and the potential of polymer physics to advance the understanding of related soft mat-ter systems. The organizers intend to focus on the impact of chain length on observed phenomena as the golden thread for the discus-sions grouping around five themat-ic areas. Abstract submission dead-line is April 1st, 2011. SoMaS Summer School 2011

The SoMaS School 2011 aims to

give attendees a broad exposure to fundamental concepts and recent advances in the research of com-plex fluids and biological materials. The school integrates knowledge from physics, chemistry and mate-rials science. The central goal is to present the advantages of such an interdisciplinary approach and to discuss current challenges in soft matter science. The SoMaS School 2011 consists of:

• Master Classes• Introductory courses• Seminars on specific topics• Intensives discussions dur-

ing posters sessions• Presentations about profes-

sional opportunities after a PhD

New International Research Group in Soft Matter Science

Concepts for the Des ign of Funct iona l Mater ia l s

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We hope you enjoy browsing softmatterworld.org and come back soon

Linda S. Hirst and Adam Ossowski

SoftMatterWorld.org

The fourth session of the Warsaw School of Statistical Physics will be held from June 25 to July 2, 2011 in the picturesque town of Kazimi-erz, Poland. The School is primarily aimed at introducing young scien-tists to the most important areas of research in the vast field of statis-tical physics. The organizers have invited distinguished scientists to

give comprehensive, pedagogical and inspiring lectures. The program of the School is geared towards all levels of aca-demia; PhD students, postgraduate researchers, and also to more expe-rienced scientists who would like to get acquainted with a new field and contribute to discussions. Registration and poster submis-

sion deadline is March 31st. Visit the website to read more.

4th Warsaw School of Statistical Physics

We are inviting all of our regis-tered users to submit availible posi-tions so they can be featured in the upcoming April 2011 Noticeboard Bulletin. These include faculty posi-tions, undergraduate, doctoral and postdoctoral openings, and even summer schools and internships. If you would like an opening ad-vertised just send an email to the

editor, editor.softmatterworld@gmail.com with the following information;

• Title of position• Affiliated university or institu-

tion• A brief description of the po-

sition (100-150 words)• Duration of opening• Contact information • Website/URL

Visit the noticeboard to see some examples. All postings on the no-ticeboard are free of charge.

Submit Position Openings for Upcoming Noticeboard Bulletin