06 July 2026
Congratulations to Jan and to our collaborators in Frank Giesselmann's group at the University of Stuttgart and in Per Rudquist's group at Chalmers University of Technology for their latest publication in
npj Soft Matter, "Electrospun fibers with axially polarized ferroelectric nematic core"! A combination of our longstanding electrospinning work with the exciting and emerging world of ferroelectric nematic liquid crystals, this work reports on the results of electrospinning polymer fibers containing a ferroelectric nematic liquid crystal core. The unique properties of ferroelectric nematics suppress the onset of Rayleigh–Plateau instability, giving rise to very easy, continuous filling and unusual behavior in the fibers.
The article is open access and free to read. Congrats again to the team!
/LWH/
09 March 2026
Congratulations to Zory and Jan on their latest publication, "Orientational ordering benefits nanorod sonication", which
went online today in Physical Review Materials! A work very long in the making, this is a systematic study of the interplay between sonication and ordering in suspensions of rods (in particular, the cellulose nanocrystals we use) and how phase transitions ultimately affect the behavior of the suspensions (even after returning to the "original" state).
The article is free to read (and download) online.
/LWH/
30 January 2026
Congratulations to ESMP alumna Deniz Avşar and ESMP overlord Jan on their newest publication in
Advanced Optical Materials, "
Circularly Polarized Structural Color Pigments Tunable Across the Full Visible Spectrum"! In this work, inspired in part by jewel beetles, Deniz and Jan (though especially Deniz) explore the camouflaging of patterns sensitive to circular polarization by using cholesteric spherical reflectors. By color mixing and dye infusion, they achieved color combinations that are virtually invisible to the unaided eye, but become very apparent when viewed through circular polarizers (like some of the glasses used for watching 3D movies in 3D).
The article is open access and free to read; a great start to 2026.
/LWH/
27 March 2025
Congrats to Najiya and Jan for their recent publication, "
Oligomer-Derived Photoresponsive Liquid Crystal Elastomers with Biocompatible Operating Temperature", in
Advanced Optical Materials! In this work, they demonstrate liquid crystal elastomers capable of responding to light at temperatures close to body temperature, a step towards the aim of the ECLECTIC project of producing liquid crystal elastomer actuators for artificial vasculature. Accepted just in time for Najiya's recent PhD defense, it's now finally online for all to see.
\LWH\
11 December 2024
Congratulations to Yansong, Jan, alumni Rijeesh and Hakam, and our collaborators in the Laboratory for Photovoltaics for their recent publication, "Arbitrary and active colouring of solar cells with negligible loss of efficiency", in Energy & Environmental Science! As part of the FNR-funded project LETZCOLOR, this recent work explores the use of polymerized liquid crystals to beautify solar cell panels without any cost to the performance of the panels.
The article is free to access and read; a very nice way to end the year!
\LWH\
29 March 2023
Congrats to our alumni Anjali, Rijeesh and Jan for a
recent paper: Impact of mesogenic aromaticity and cyano termination on the alignment and stability of liquid crystal shells.
\ XM
07 August 2020
Many congratulations to JungHyun, Jan and the team for the recent paper "
Dynamic tuning of the director field in liquid crystal shells using block copolymers" published in Physical Review Research.
\AS
31 May 2020
Many congratulations to Catherine and Jan for the new article "
Disruption of electrospinning due to water condensation into the Taylor cone", published in
ACS Applied Materials & Interfaces. This paper has open access.
\AS
03 September 2019
Congratulations to Anjali, Jampani, and Jan on their new article published in Langmuir: "
Realignment of liquid crystal shells driven by temperature-dependent surfactant solubility"This is the study of nematic LC shells stabilized by temperature responsive surfactant. Study shows how one can change the alignment of LC just by varying the temperature. Click
here for the full article.
\AS
29 June 2019
Congratulations to Catherine and Jan on the new publication RSC's Soft Matter:
"Isotropic-Isotropic phase separation and spinodal decomposition in liquid crystal-solvent mixtures" experimentally & theoretically reveals evidence of coexisting isotropic phases in simple mixtures of ethanol, 5CB, and water. Even though the nematic LC 5CB is arguably the most studied commercial liquid crystal worldwide, for the first time this study highlights experimental evidence of spinodal decomposition and nucleation and growth occuring between two isotropic phases and a single nematic phase between this common compound and equally common solvents.
(Click the image below to visit the article:
All supplementary info is open access!)
\AS\
19 September 2018
Congratulations to Anjali & Jan on the new publication in Liquid Crystals: "Influence of head group and chain length of surfactants used for stabilising liquid crystal shells"
This is the systematic study of the effect of different surfactants on Nematic LC shell, in terms of stability and alignment.
/AS/
24 May 2018
(Click the image above to read the article online, it is Open-Access)
Congratulations to Matt & Jan on the new publication in Advanced Materials: “Cholesteric Liquid Crystal Shells as Enabling Material for Information‐Rich Design and Architecture”!
Matt is a long time collaborator of Jan's since his time as a professor at SNU in South Korea. Some of us in the group got the chance to meet him, but eventually we'll all see each other again in a few days when Matt stops by our lab. Originally an architect by training, Matt worked on (and is probably still working on) many interdisciplinary projects involving robotics, and functional architecture design. He is currently a professor at the New Jersey Institute of Technology.
In this new article Matt, Jan and a few other collaborators at the SNT (Security, Reliability and Trust) Centre in Luxembourg discuss the possibilities of using cholesteric LC shells as sources for information technology in various architecture, drone, and robotics concepts and applications.
/CGR/
29 March 2018
(Click the image above to read the article online, it is Open-Access)
Congratulations to Camila, Christina & Jan on the publication in Nature Asia Materials: "Fractionation of cellulose nanocrystals: enhancing liquid crystal ordering without promoting gelation" !
In a successful collaboration with Prof. Roland Sanctuary's group here at the physics & materials science research unit, this latest research on CNCs (cellulose nano crystals) describes in detail how controlling the fractionation of CNCs according to length can help in preventing the onset of gelation in solutions. The experimental results are discussed against what is already known regarding the aggregation of colloids based on the presence of counterions, and what still needs to be established in the field.
According to the authors: "Our results shine new light on the competition between liquid crystal formation and gelation in nanoparticle suspensions and provide a path for enhanced control of CNC self-organization for applications in photonic crystal paper or advanced composites."
/CGR/
15 March 2018
(Click the graphical abstract above to read the article online, it is Open-Access)
Congratulations to Anshul & Jan on the publication in Materials: “Electrospun Composite Liquid Crystal Elastomer Fibers”!
This is the first study to date that shows and analyzes the irreversible actuation of photo-crosslinkable reactive mesogens single axially electrospun with a carrier polymer, to create liquid crystal elastomer (LCE) fibers. Don't forget to check out the supplementary info for more details!
/CGR/
19 February 2018
(Click the graphical abstract image above to access the article online, please email either Jan or Rao if you cannot download the pdf file)
Congratulations to Larry & Rao on the publication in Langmuir titled: “Microfluidic Tensiometry Technique for the Characterization of the Interfacial Tension between Immiscible Liquids”!
This is Larry's 1st paper in our group (!) and also Rao's 1st time serving as last author on a paper (!)
In this study, Larry and Rao borrow inspiration from the biologists and use the novel technique of micropipette aspiration (commonly used to measure the viscoelastic properties of living cells) to measure the interfacial tension of 5CB, water, and surfactants with a high degree of accuracy (from the sub-millinewton per meter to several hundred millinewton per meter range) solely from experimental observations of the droplet deformation. This is highly unique as information on the liquid density is not needed to find the interfacial tension.
/CGR/
01 September 2017
(click the above image to access the article online)
Congratulations to Martin on the publication in J. Mater. Chem. C of his dielectric spectroscopy study “Why organically functionalized nanoparticles increase the electrical conductivity of nematic liquid crystal dispersions”!
This paper gives a first systematic study of how and why nanoparticle doping raises the electrical conductivity of thermotropic liquid crystals like the commonly studied 5CB. By a careful analysis of the dielectric spectra, he shows that the hydrodynamic radius of the ionic charge carrier is much smaller than the nanoparticles, ruling out the particles themselves as the source of conductivity. The ligand molecules are also not the reason, as is demonstrated by strong sonication of the dispersions, such that the ligands detached from the nanoparticles. While this causes nanoparticle aggregation and the loss of suspension stability, the effect on conductivity is negligible. The ligand shell is, however, partially responsible, because the ions giving rise to the conductivity increase are most likely remnants from the ligand-functionalized nanoparticle synthesis process. We propose that these ions are brought in with the ligand shell when the particles are dispersed in the 5CB. Interestingly, the ions appear not to be released in an isotropic and aromatic solvent such as toluene, which is often the host for commercial gold nanoparticle suspensions, but 5CB is an ideal host for their dissolution. The aliphatic ligand shell has a higher compatibility with 5CB than with toluene, thanks to the alkyl tail of 5CB, and at the same time the high polarity of the 5CB (due to the cyano group) allows better ion dissolution than in regular hexane. Finally, the nematic order of the 5CB solvent provides an anisotropic environment in which the ligands are stretched out preferentially along the director, making release of ligand-bound ions to the solvent more likely.
/JL/
06 August 2016
Congrats to Catherine and Anshul, whose paper on non-electronic toluene vapor sensing using electrospun PVP fibers filled with nematic 5CB liquid crystal is now
available (Open Access) from the
Liquid Crystals website. In the article they demonstrate that there are two types of response to toluene vapor exposure, one slow and one fast. The slow one corresponds to a toluene diffusion-induced clearing transition, whereas the fast one is connected to a change in liquid crystal director field configuration, but the 5CB remains in the nematic phase. This fast response is seen across the mat within a fraction of a second, even several centimeters away from the exposure point, indicating that the detection threshold is very low. They also show that the responses of uniformly cylindrical fibers and beaded fibers are quite different, the latter allowing detection by the naked eye, without polarizers.
Download the paper (no subscription needed) here.
28 May 2015
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.
29 August 2014
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).
03 April 2014
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.
