Experimental Soft Matter Physics
2014

Kevin defends his B.Sc. thesis

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Congrats to Kevin for defending his B.Sc. thesis entitled "Topological Defects in Liquid Crystal Shells" very successfully. Kevin did a great job while he was with us and we hope that his and JungHyun's research efforts will soon be summarized in a new paper.

Bandol Summer School on Liquid Crystals

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For the first time in several years, the Bandol Summer School on Liquid Crystals took place again in the end of September - beginning of October. Jan was one of the teachers and JungHyun and Zory took part as students. We had a great time with a curious and imaginative group of students (and teachers), making the school as nice an experience as it was during previous years.

Kevin Reguengo de Sousa joins the group

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Kevin Reguengo de Sousa, undergraduate student in the University of Luxembourg physics program, will be carrying out his thesis work with the group during the fall. He will work together with JungHyun on liquid crystal shells.

Duckhee Kim comes to Luxembourg

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Duckhee Kim, who did an internship with Jan while Duckhee did his undergraduate studies at SKKU and Jan was at SNU, is starting his Master studies in physics at University of Luxembourg. He joins the Experimental Soft Matter Physics group on part-time basis as a 'student researcher'.

New article on electrospinning in ACS Applied Materials & Interfaces

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A beautiful study by Dae Kyom, demonstrating how capillary forces from water condensing on the outside of fibers during electrospinning can drastically influence the shape and core content of the fibers, is now published as an article in ACS Applied Materials & Interfaces, 6, 18, 16441−16447 (2014). You can find the paper here (subscription required).

JungHyun gives talk at Liquid Matter 2014

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JungHyun and Jan are attending the 9th Liquid Matter 2014 conference in Lisbon, where JungHyun gives a talk entitled "Tunable multicolored patterns from photonic cross communication between cholesteric liquid crystal droplets" (Jan just got a poster Winking ). We take the opportunity to discuss our collaborations with Frank Giesselmann from Stuttgart (left) and Jun Yamamoto from Kyoto (right).

Three American guests

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We welcome (from left to right) Michael Varga, Collin McGinty (both Kent State University) and Catherine Reyes (Cornell University) as visitors of the ESMP group from 21st of June to 26th of July 2014. Their visit is part of an IRES project managed by our collaborator Tony Jakli at Kent State University, including also Margaret Frey at Cornell and Ralf Stannarius and Alexey Eremin at Otto von Guericke University Magdeburg in Germany. While in Luxembourg, the three will be working on electrospinning core-sheath nano- and microfibers functionalized by low molar mass materials in the core.

JungHyun Noh joins as Ph.D. candidate

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JungHyun Noh is the group's first Ph.D. candidate after the move to Luxembourg. She secured a personal Ph.D. grant from the Fonds National de la Recherche Luxembourg (FNR) for a project entitled ULISCO. The project deals with innovative ways of making liquid crystal shells as well as the study of the topological defects arising in these shells.

New ChemPhysChem paper on cholesteric liquid crystals of cellulose nanocrystals (CNC)

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For a special issue of ChemPhysChem on the physical properties and behaviour of liquid crystals, we published a study on how the orientation and pitch of the helix in films formed by drying cholesteric liquid crystalline suspensions of cellulose nanocrystals (CNC) can be controlled with high accuracy based on a few simple considerations. The first point is that tactic boundaries, always present if one starts with suspensions that are in the phase coexistence regime, randomize the orientation of the helix, thereby giving rise to the irregular mosaic texture (left) often seen when drying films from low concentration CNC suspensions. By simply raising the concentration such that the initial suspension is fully liquid crystalline, a film with uniformly standing helix and much more uniform pitch can be achieved (right). Moreover, we show that an orbital shear flow can have a good effect in orienting the helix even when tactoids cannot be avoided. The work is a collaboration with the LC Nano lab of Prof. Giusy Scalia and the group of Prof. Lennart Bergström at the Materials and Environmental Chemistry Department of Stockholm University. You can find the paper at the ChemPhysChem web site here. Unfortunately, we could not include color images in the final version of the paper, so be sure to also download the Supporting Information file, which contains all images in color version (the color is important for the discussion).

Note: if you want to learn more about liquid crystals from CNC, please check out our recent review article (open access!) in NPG Asia Materials.

Zornitza Tosheva joins the group

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Zornitza Tosheva joins the Experimental Soft Matter Physics group as a Research Associate. Zory was previously investigating radon in different water sources and will now change to study liquid crystals and colloids.

Jan gives honorary lecture at the German Liquid Crystal Conference

At the 2014 German Liquid Crystal Conference in Magdeburg Jan was invited to deliver the honorary Vorländervorlesung. The title of his presentation, which contained some quite general reflections about our current research situation, was "With an open attitude, new doors open".

Move to Luxembourg

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Since March 1st 2014 the “Soft Nano- and Microstructures Group” at Seoul National University ceased to exist and it is replaced by the “Experimental Soft Matter Physics” group at the University of Luxembourg, where Jan since this date is full professor in physics, at the Physics & Materials Science Research Unit. This web site will eventually be updated to reflect the new situation and the changes it will entail. Our current main research foci (on functional composite fibers produced by electrospinning; on liquid crystalline shells [low molar mass and elastomeric]; and on liquid crystalline self-assembly of cellulose nanocrystals) will remain and we are still very interested in transdisciplinary research, although there will be an increased focus on physics with more room for fundamental research than what the situation in Korea allowed.







Bernd Wicklein visits the SNM and LC Nano groups

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Dr. Bernd Wicklein from Stockholm University is visiting the Lagerwall and Scalia groups (SNM and LC Nano, respectively) for two weeks within the framework of our Swedish-Korean collaboration on cellulose nanocrystals.



JungHyun awarded for her presentation at KLCC

IMG_3999IMG_4028JungHyun Noh received a best presentation award for her talk at the Korean Liquid Crystal Conference in Jeonju, 23rd-24th of January 2014, on the microfluidic preparation of cholesteric liquid crystal droplets and the analysis of their photonic behaviour. Congratulations! This work was also recently published in Journal of Materials Chemistry C, which chose to feature her work on the cover page.

New review on cellulose nanocrystal self-assembly in NPG Asia Materials

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Our review article on the balance between liquid crystalline self-assembly and glass formation in colloidal suspensions of cellulose nanocrystal (CNC) is now published (open access!) in NPG Asia Materials. You can download it without subscription from the nature.com web site here. The paper is a result of our collaboration with Lennart Bergström’s group at Stockholm University as well as with Giusy Scalia’s group here at the GSCST. We discuss how the tendency for liquid crystalline ordering in colloidal suspensions of crystalline nanorods of cellulose competes with gelation, or glass formation. The liquid crystal formation dominates at low CNC concentration but at somewhat higher concentrations gelation sets in and prevents further changes of the liquid crystal phase diagram, as well as a further reduction under equilibrium conditions in the helical pitch of the chiral nematic phase that is the single liquid crystal phase found so far in CNC suspension. We briefly discuss how one might proceed to shift the balance in favor of liquid crystal ordering and thus see also transitions to higher ordered liquid crystal phases, e.g. columnar or smectic.

Feature on J. Mater. Chem. C cover page

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Journal of Materials Chemistry C chose to feature our article on photonic cross communication between cholesteric droplets on the front page of issue 5, volume 2, 2014. Congratulations JungHyun!