23 December 2015
Just in time for Christmas,
JungHyun's beautiful collection of liquid crystal shells got to decorate the
cover of issue 2 of volume 12 of Soft Matter. Her article "
Influence of interface stabilisers and surrounding aqueous phases on nematic liquid crystal shells", written together with
Kevin and
Jan, appears on page 367 of this issue. Congratulations on your second journal cover, JungHyun!
27 November 2015
With a slight delay, it is finally time on Thursday 10th of December for Jan to give his inaugural lecture at University of Luxembourg, entitled
Contrasts drive self-assembly and beauty is born. This is a popular scientific lecture open to the public, and it will span a broad spectrum, from giving some fascinating glimpses of the research we do in the group to discussing the benefits of cross-fertilizing fundamental and applied research, taking an open-minded and interdisciplinary attitude.
The lecture will take place in
Salle Tavernas, Campus Limpertsberg (the old monastery on 102 Avenue Pasteur) at 18:00. You are most welcome!

10 November 2015
The Experimental Soft Matter Physics group will participate in the
Luxembourg Science Festival, during the sessions for school classes on Thursday 12th and Friday 13th of November. We will exhibit a show on polarized light and birefringence, and how observation between crossed polarizers can be used to reveal information about materials that is hidden to the naked eye, like where stresses build up and whether or not an anisotropic order exists on macroscopic scale.
We will be in the "Tente parvis", at workshop 38: "Lumière fantastique!".
26 October 2015
Congratulations to JungHyun and Kevin! During Kevin's bachelor thesis work (supervised by JungHyun) they discovered a very surprising textural change during the nematic-isotropic transition of liquid crystal shells. This became the start of a detailed investigation of what the substances that surround liquid crystal shells, typically surfactants and random coil polymers dissolved in aqueous mixtures, actually do to the liquid crystal. Now this study has been accepted for publication as a Communication in
Soft Matter.
You can download the 'just accepted' version here, and you will then see that water actually enters the liquid crystal, affecting its clearing point, and surfactant can go through from one side to the other, turning a hybrid shell uniformly homeotropic after some time. On the other hand, if the surfactant concentration is too low, the alignment is planar, because then the planar-aligning influence of water dominates. Polymers like PVA just stabilize the shells, they don't affect the alignment.
05 August 2015
Congratulations to YooMee, whose M.Sc. research on the preparation of multiresponsive fibers, by electrospinning dual-core fibers with different liquid crystals next to each other, is now on-line at
Journal of Materials Chemistry C. The paper, published in collaboration with Prof. Changsoon Kim at Seoul National University, describes the possibilities opened by incorporating multiple liquid crystals in one and the same fiber, giving a single fiber multiple functions (like selective reflection and birefringence, as in the bottom right pane of the ToC graphic, reproduced here). Apart from the feat of producing the fibers, YooMee gives two messages of great practical importance concerning liquid crystal electrospinning. First, she confirms the
recent observation in a paper with DaeKyom as lead author, that electrospun core-sheath fibers must not be collected on hydrophilic substrates like ordinary glass or silicon chips, because then capillary forces from condensed water will deform the fibers. In YooMee's case, she found that the phenomenon even leads to mixing of the adjacent cores. Second, while ionic surfactants are a useful additive to the polymer solution in solid fiber spinning, since they increase the conductivity and reduce the surface tension, they are a bad choice when the fiber contains a liquid crystal core. YooMee found dramatic reductions in clearing point of the encapsulated liquid crystal whenever the polymer sheath solution contained surfactant, indicating that the surfactant actually enters the liquid crystal and disturbs its order.
Download her paper at Journal of Materials Chemistry C!30 July 2015
We have the fortune to welcome Dr. Johanna Bruckner in our team. Johanna recently defended her Ph.D., carried out under the supervision of Frank Gießelmann, at the University of Stuttgart, and she secured a fellowship from the Dr. Leni Schöninger Stiftung for doing a six-month post-doc with us in Luxembourg. She will be working on liquid crystalline suspensions of cellulose nanocrystals (CNC) in various solvents. In doing so, she will be working closely with our other CNC researchers, in particular Camila, who is the Ph.D. candidate in the MISONANCE project.
01 July 2015
It is our great pleasure to welcome Yong Geng to our group as a post-doc. After obtaining his Ph.D. with Prof. Maria Helena Godinho in Lisbon he worked as a post-doc with Prof. Ralf Stannarius and Dr. Alexey Eremin in Magdeburg, before he came to Luxembourg. He will be working on colloidal crystals of cholesteric shells, produced in a microfluidic set-up, focusing on the optical properties and the pattern formation of these systems. This research is the core of the interdisciplinary dual-PI project UNIQUE, funded by University of Luxembourg. The second partner of the project is the team around Gabriele Lenzini and Peter Ryan at the UL's Interdisciplinary Center for Security and Trust, which will analyze the patterns generated by the colloids from an information content point of view. Young will thus interact closely with Samir Ouchani, a post-doc in computer science working under the guidance of Gabriele.
14 June 2015

In connection to Jan's trip to Korea for YooMee's defense, he took the opportunity to visit wearable technology artist Younghui Kim (Hongik University) and robotics artist/designer Mathew Schwartz (Advanced Institute of Convergence Technologies) to discuss their collaboration within the framework of Jan's ERC project INTERACT. Here the three are gathered in Younghui's fantastic studio in Seoul, surrounded by her artwork.

A new result from our fruitful collaboration with Stockholm University on cellulose nanocrystal suspensions appeared as an ASAP article in Langmuir today. It contains the best measurements of helix pitch in
equilibrium cholesteric suspensions to date, based on a combination of x-ray and optical diffraction measurements. You can
find the paper here.

Our collaborator at the Advanced Institutes of Convergence Technology (Suwon, Korea), Mathew Schwartz, visits the ESMP group in the beginning of May, giving a talk entitled "Research problem finding and solving through Art and Design". In connection to this visit we had intense discussion around our work on soft robotics within the project INTERACT.
15 April 2015
PhD StudentsWe welcome Camila Honorato as a member of our group! She will be working as a doctoral candidate in the MISONANCE project, carried out in collaboration with the team of Prof. Tanja Schilling at PhyMS, UL. Camila will study the self-assembly of water-suspended cellulose nanocrystals into lyotropic liquid crystal phases, and how this self-assembly competes with the tendency of electrostatically charged nanorod suspensions to arrest into a jammed state. She will interact closely with Anja Kuhnold from Prof. Schilling's group, who is doing theory and computer modeling corresponding to Camila's experiments.
On the 12th of March 2015 the European Research Council (ERC)
publicized the list of this year's Consolidator Grant winners, making it official that Jan's proposal INTERACT was selected for support. The support means that for the next five years the Experimental Soft Matter Physics group will be working very actively on wearable technology, soft robotics and innovative techniques for secure authentication. As the project gets going (current projected starting date is 1st of April 2015) there will be many updates.
On Tuesday 10th of February 2015, Jan gave an invited talk entitled “Dynamic and complex optical patterns from colloids of cholesteric liquid crystal droplets” at the SPIE meeting in San Francisco, in the session “Emerging Liquid Crystal Technologies X”. You can
watch the screen recording of the talk (you see the slides and hear the voice) here.
01 February 2015
ProjectsToday is the start of the project MISONANCE, a joint research thrust with the Theory of Soft Condensed Matter Physics group, lead by Tanja Schilling, funded within the CORE scheme of the Fonds National de la Recherche Luxembourg (FNR). The project deals with the balance between liquid crystalline self-assembly and glass formation in suspensions of cellulose nanocrystals, and the preparation of photonic crystal films based on this new bionanomaterial. The project is Jan's first large-scale project on cellulose and it will continue the excellent collaboration with the group of Prof. Lennart Bergström at Stockholm University (non-contracting partner). The theme of MISONANCE is largely the issues discussed in our review article published in NPG Asia Materials last year (the picture is from this open-access paper, which you can
download free of charge and without subscription here).
15 January 2015
PhD StudentsIt is with great pleasure that we welcome our new Ph.D. candidate, Catherine Reyes, coming from Cornell University where she carried out her Master studies with Prof. Margaret Frey. Catherine should have arrived already in September but the paper work for allowing a US citizen and Cornell graduate to start as Ph.D. candidate in Luxembourg turned out to be beyond our wildest imagination… Anyway, she is finally here and she will be working full time on liquid crystal-functionalized electrospun fibers for wearable technology.