Experimental Soft Matter Physics

Videos from TEDxSNUSuwon now on-line

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The videos of the talks at TEDxSNUSuwon (organized by a team comprising Jan and YooMee from the SNM group) are now on-line. You can for instance watch the talk on wearable technology by our collaborator Prof. Younghui Kim of Hongik University (the picture is from this talk).

JungHyun defends her M.Sc. thesis

JungHyunDefenceCongratulations to JungHyun Noh who successfully defended her M.Sc. thesis, “Two Novel Cholesteric Liquid Crystal Systems: Microfluidics-Produced Droplets and Self-Assembled Cellulose Nanocrystal Films” on the 6th of December 2013 at the Graduate School of Convergence Science & Technology. The thesis will soon be available for download from the publications page.

New J. Mater. Chem. C paper on cholesteric droplet photonic cross communication

We have a new paper coming out as a Communication in Journal of Materials Chemistry C, dealing with the intriguing photonic communication between droplets of cholesteric liquid crystal. JungHyun and Hsin-Ling used our microfluidic equipment to produce mono disperse droplets of selectively reflecting short-pitch cholesteric liquid crystals, and found amazing patterns. When Irena Drevensik-Olenik (Jozef Stefan Institute and University of Ljubljana) visited us, we had a good microscopy session together and were able to elucidate the origin of the patterns. The paper describes the behavior of multiple cholesteric droplets under varying illumination conditions and with varying pitch lengths, explains the phenomena, and discusses possible applications routes. You can read the paper here on the J. Mater. Chem. C web site.

TEDxSNUSuwon 16.11.2013

On Saturday 16th of November 2013 the GSCST and AICT will be hosting the first Korean TEDx event targeted towards an international audience: TEDxSNUSuwon. All talks will be delivered in English and the web site will be translated to multiple languages (at the time of writing this, English, German, Swedish and Finnish are active, the other languages will be added soon). The theme of the event is “Convergence” and we will have an awesome line-up of scientists, artists and performers active in Korea. Check out the web site for more information, and become a fan of the TEDxSNUSuwon Facebook page!

Hsin-Ling defends her Ph.D. thesis

Congratulations to Dr. Hsin-Ling Liang who successfully defended her Ph.D. thesis, “Microfluidic Produced Liquid Crystalline Shells: Self-assembled structures in nematic and smectic shells” on the 25th of September 2013 at Johannes-Gutenberg-Universität Mainz. The thesis will soon be available for download from the publications page.

Our LC review article is popular

Our review article A New Era for Liquid Crystal Research: Applications of Liquid Crystals in Soft Matter Nano-, Bio- and Microtechnology, on modern developments in liquid crystal research, published in Current Applied Physics, was the 4th most downloaded article among all Elsevier journals in the field of Condensed Matter Physics in the first half of 2013! It is now freely available for anyone to download until end of October. You can read the full list of the top 25 articles here.

Sarah Dölle visits the SNM group

Sarah Dölle, former diploma student of Jan Lagerwall and now a Ph.D. student of Prof. Ralf Stannarius at University of Magdeburg, visited the SNM group and LC Nano lab (Giusy Scalia’s group) on Friday 19th of July. She gave a beautiful talk about high-speed video studies of droplet impact on free-standing smectic liquid crystal films. You can read the abstract here.

Summer guests of SNM and LC Nano groups

On the 12th of July 2013, Julia Martius (left), Joe Angelo (middle) and Larry Honaker (right) came to Seoul to spend 3 months (Julia) and 1 month (Joe and Larry) together with us. Julia has just finished her Bachelor thesis at the Karlsruhe Institute of Technology in Germany and as a DAAD RISE scholarship holder she will be working during summer and early fall in the SNM group on producing and studying liquid crystal droplets and shells. Joe and Larry are visiting from Kent State University within the framework of an NSF IRES grant for which Joe’s advisor, Prof. Antal Jakli, is the PI. The SNM group of Jan Lagerwall and the LC Nano lab of Giusy Scalia are Korean partners in this multinational project. Joe and Larry will be working on electrospinning and functionalization of polymers with liquid crystals and nano particles. (Photo by Dae Kyom Kim.)

Stefan defends his PhD.

Congratulations to Dr. Stefan Schymura who successfully defended his Ph.D. thesis, “Liquid Crystalline Carbon Nanotube Suspensions: From Unique Challenges to Unique Properties” on the 4th of July 2013 at Martin-Luther-Universität Halle-Wittenberg. The thesis is available for download in pdf format by following this link.

Our Nature Communications paper featured at Soft Matter World

Our Nature Communications paper on liquid crystal elastomer micro pumps, co-authored with the University of Mainz group of Prof. Rudolf Zentel, is featured in the May 2013 issue of Soft Matter World. You can read a popular scientific introduction to the paper here or download the article from Nature Communications here.

Eva Enz defends her Ph.D.

Congratulations to Dr. Eva Enz who successfully defended her Ph.D. thesis, “Electrospun Polymer - Liquid Crystal Composite Fibres” on the 16th of April 2013 at Martin-Luther-Universität Halle-Wittenberg. The thesis is available for download in pdf format by following this link.

YooMee Kye joins the SNM lab

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YooMee Kye, new student at the GSCST on a combined Master-PhD track, joins the SNM lab. She will (at least to begin with) be working with electrospinning of liquid crystal-functionalized fibers with multiple cores.

Perspective article on liquid crystal electrospinning on-line

Our Perspective article in J. Polym. Sci. B: Polymer Physics on the science and - in particular - the application potential of electrospun polymer fibers functionalized by liquid crystals is now on-line. You can download the paper without any subscription here. (Perspective and Review articles are available for free download from J. Poly. Sci. B: Polym. Phys.) It briefly introduces liquid crystals to the general polymer audience, giving a particular emphasis on the response to the strong confinement that takes place when introducing liquid crystals in core-sheath fibers, and then focuses mainly on the application possibilities of this new class of liquid crystal composite. After reviewing the current state of the art in the field of liquid crystal electrospinning and a few selected other attractive examples of composite fiber electrospinning, we discuss some interesting new developments in the general liquid crystal research field that may be very beneficial to connect with electrospinning. These are gas sensing with liquid crystals, mechanical sensing with liquid crystals, and mechanoelectrical power conversion using flexoelectric liquid crystals. Finally, the paper is rounded up with an overview of the application possibilities that can be envisaged by considering a cross fertilization of the previously discussed activities. These are goals that we are currently working towards in our group, and we are very happy to collaborate with anyone interested that would like to provide complementary expertise. Alternatively, if you would first like to simply explore the possibilities of liquid crystal electrospinning in your own lab, I will be more than happy to provide advice on how to set up your own equipment. Please contact us if you would like to know more.

New paper on liquid crystal shells published

Our paper in the Philosophical Transactions of the Royal Society A (the longest running journal dedicated to science, established in 1665, with contributing authors including Isaac Newton, James Clerk Maxwell, Michael Faraday and Charles Darwin) on defect configurations in nematic and smectic liquid crystal shells is published. You can download the paper here (free access until 31st of March). In the paper we give a brief overview to the science and possible applications of liquid crystalline shells and how they are currently produced using an elegant microfluidic technique, and we then concentrate on our own contributions that focus on the nematic-smectic A transition and the smectic A-smectic-C transition in the shells. New additions in this paper includes a description of how the director field pattern in a planar-aligned SmA shell rearranges in response to a rotation of the shell with respect to gravity, how a negative-signed defect can be produced in a nematic shell by seeding more positive-signed defects within the shell than required (and allowed, if they would not be compensated by negative defects) by topology, and how the SmA-SmC transition appears in a homeotropic-aligned shell (the picture to the left is from a SmC shell of this type).

Two students from Germany visiting

Martin Kühnast and Hsin-Ling Liang, Ph.D. students from Germany (Hsin-Ling is originally from Taiwan) at Martin Luther University Halle-Wittenberg and University of Mainz, respectively, are visiting the SNM and LC Nano labs in February. Hsin-Ling will work together with JungHyun Noh on liquid crystal shell production and analysis and Martin will work primarily on carbon nanotubes in thermotropic liquid crystals, largely in collaboration with the LC Nano lab of Prof. Giusy Scalia.

lcsoftmatter.com on-line again!

Finally, after months of down-time due to our previous provider, which became totally unreliable and unresponsive, www.lcsoftmatter.com is again working. We have a new provider and everything now seems to run smoothly. Sadly, the downtime affected not only the web site but from time to time also the e-mail. Thus, if you have been trying to contact Jan and never got a response, this may have been the reason.

Paper on SEM characterization of liquid crystal-filled electrospun polymer fibers published on-line

Following up on our optical characterization of electrospun fibers containing cholesteric liquid crystals we have now published a paper describing a nanoscale characterization of the same type of fibers by scanning electron microscopy, correlated with polarizing optical microscopy investigations. The study, which was carried out in collaboration with Prof. Giusy Scalia and co-workers (LC Nano lab), compares fibers prepared with slightly varying sheath solution compositions. We find large variations of external morphology as well as the degree and character of liquid crystal filling, depending on the exact spinning conditions and composition of the sheath solution. You can download the paper, published in Macromolecular Materials & Engineering, here.