scholarly journals Liquid crystal elastomer shell actuators with negative order parameter

2019 ◽  
Vol 5 (4) ◽  
pp. eaaw2476 ◽  
Author(s):  
V. S. R. Jampani ◽  
R. H. Volpe ◽  
K. Reguengo de Sousa ◽  
J. Ferreira Machado ◽  
C. M. Yakacki ◽  
...  
Keyword(s):  
Order Parameter ◽  
Soft Matter ◽  
Orientational Order ◽  
Liquid Crystallinity ◽  
Liquid Crystal Elastomer ◽  
Negative Order ◽  
Value Range ◽  
Scalar Order Parameter ◽  
New Challenges ◽  
Soft Matter Physics

Liquid crystals (LCs) are nonsolids with long-range orientational order, described by a scalar order parameter〈P2〉=12〈3cos2β−1〉. Despite the vast set of existing LC materials, one-third of the order parameter value range,−1/2< 〈P2〉 < 0, has until now been inaccessible. Here, we present the first material with negative LC order parameter in its ground state, in the form of elastomeric shells. The optical and actuation characteristics are opposite to those of conventional LC elastomers (LCEs). This novel class of anti-ordered elastomers gives access to the previously secluded range of liquid crystallinity with 〈P2〉 < 0, providing new challenges for soft matter physics and adding a complementary type of LCE actuator that is attractive for applications in, e.g., soft robotics.

Deuteron NMR investigation on orientational order parameter in polymer dispersed liquid crystal elastomers

2020 ◽  
Vol 22 (40) ◽  
pp. 23064-23072
Author(s):  
Andraž Rešetič ◽  
Jerneja Milavec ◽  
Valentina Domenici ◽  
Blaž Zupančič ◽  
Alexej Bubnov ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Order Parameter ◽  
Orientational Order ◽  
Orientational Order Parameter ◽  
Liquid Crystal Elastomer ◽  
H Nmr ◽  
Polymer Dispersed Liquid Crystal ◽  
Polymer Dispersed ◽  
Liquid Crystal Elastomers ◽  
Magnetically Aligned

Orientational order parameter of magnetically aligned liquid crystal elastomer particles suspended in a cured silicone matrix is assessed using 2H-NMR spectroscopy. Obtained results correspond well with the composite's thermomechanical response.

scholarly journals Coincident molecular auxeticity and negative order parameter in a liquid crystal elastomer

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
D. Mistry ◽  
S. D. Connell ◽  
S. L. Mickthwaite ◽  
P. B. Morgan ◽  
J. H. Clamp ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Order Parameter ◽  
Liquid Crystal Elastomer ◽  
Negative Order

Introduction to molecular simulations in soft matter

2017 ◽  
Author(s):  
J.-L. Barrat ◽  
J. J. de Pablo
Keyword(s):  
Phase Space ◽  
Numerical Methods ◽  
Theoretical Basis ◽  
Soft Matter ◽  
Relevant Literature ◽  
Coarse Grained ◽  
Soft Interfaces ◽  
Molecular Scale ◽  
Soft Matter Physics ◽  
The Continuum

We describe the main features of the coarse-grained models that are typically useful in modelling soft interfaces, from force fields to the continuum descriptions involving density fields. We explain the theoretical basis of the main numerical methods that are used to explore the phase space associated with these models. Finally, three recent examples, illustrating the spirit in which relatively simple simulations can contribute to solving pending problems in soft matter physics, are briefly described. Clearly, a short series of lectures can offer, at best, a biased and restricted view of the available approaches. Our aim here will be to provide the reader with such an overview, with a focus on methods and descriptions that ‘bridge the scale’ between the molecular scale and the continuum or quasi-continuum one. The objective to present a guide to the relevant literature—which has now to a large extent appeared in the form of textbooks.

scholarly journals Liquid Crystal Ordering in the Hexagonal Phase of Rod-Coil Diblock Copolymers

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1262
Author(s):  
Mikhail A. Osipov ◽  
Maxim V. Gorkunov ◽  
Alexander A. Antonov
Keyword(s):  
Liquid Crystal ◽  
Order Parameter ◽  
Density Functional ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Hexagonal Phase ◽  
Orientational Order ◽  
Order Parameters ◽  
Copolymer Composition ◽  
Rigid Rod

Density functional theory of rod-coil diblock copolymers, developed recently by the authors, has been generalised and used to study the liquid crystal ordering and microphase separation effects in the hexagonal, lamellar and nematic phases. The translational order parameters of rod and coil monomers and the orientational order parameters of rod-like fragments of the copolymer chains have been determined numerically by direct minimization of the free energy. The phase diagram has been derived containing the isotropic, the lamellar and the hexagonal phases which is consistent with typical experimental data. The order parameter profiles as functions of temperature and the copolymer composition have also been determined in different anisotropic phases. Finally, the spatial distributions of the density of rigid rod fragments and of the corresponding orientational order parameter in the hexagonal phase have been calculated.

Application of video microscopy in experimental soft matter physics

2018 ◽  
Vol 32 (18) ◽  
pp. 1840012
Author(s):  
Hao Feng ◽  
Huaguang Wang ◽  
Zexin Zhang
Keyword(s):  
Video Processing ◽  
Soft Matter ◽  
Colloidal Suspensions ◽  
Real Space ◽  
Video Microscopy ◽  
Quantitative Image ◽  
Soft Matter Physics ◽  
Microscopic World ◽  
The One ◽  
Microscopic Measurement

Combining precise microscopic measurement with quantitative image analysis, video microscopy has become one of the most important, real-space experiment techniques to study the microscopic properties of soft matter systems. On the one hand, it provides a basic tool to observe and record the microscopic world. On the other hand, it offers a powerful experiment method to study the underlying physics of the microscopic world. In this paper, we review the development of the video microscopy, introduce the corresponding hardware and video processing software, and summarize the typical applications and recent progresses of video microscopy in colloidal suspensions. The future of the video microscopy in the soft condensed matter physics and interdisciplinary research is discussed.

scholarly journals Recent Advances in Conservation–Dissipation Formalism for Irreversible Processes

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1447
Author(s):  
Liangrong Peng ◽  
Liu Hong
Keyword(s):  
Soft Matter ◽  
Irreversible Processes ◽  
Recent Advances ◽  
Classical Models ◽  
Fourier Heat Conduction ◽  
Soft Matter Physics ◽  
Novel Applications ◽  
Fokker Planck Equations ◽  
Mathematical Foundations ◽  
Well Posed

The main purpose of this review is to summarize the recent advances of the Conservation–Dissipation Formalism (CDF), a new way for constructing both thermodynamically compatible and mathematically stable and well-posed models for irreversible processes. The contents include but are not restricted to the CDF’s physical motivations, mathematical foundations, formulations of several classical models in mathematical physics from master equations and Fokker–Planck equations to Boltzmann equations and quasi-linear Maxwell equations, as well as novel applications in the fields of non-Fourier heat conduction, non-Newtonian viscoelastic fluids, wave propagation/transportation in geophysics and neural science, soft matter physics, etc. Connections with other popular theories in the field of non-equilibrium thermodynamics are examined too.

scholarly journals Paraspeckles are constructed as block copolymer micelles through microphase separation

2020 ◽  
Author(s):  
Tomohiro Yamazaki ◽  
Tetsuya Yamamoto ◽  
Hyura Yoshino ◽  
Sylvie Souquere ◽  
Shinichi Nakagawa ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Soft Matter ◽  
Microphase Separation ◽  
Theoretical Framework ◽  
Internal Organization ◽  
Ribonucleoprotein Complexes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Rna Domains ◽  
Soft Matter Physics

SummaryParaspeckles are constructed by NEAT1_2 architectural long noncoding RNAs and possess characteristic cylindrical shapes with highly ordered internal organization, distinct from typical liquid–liquid phase-separated condensates. We experimentally and theoretically investigated how the shape and organization of paraspeckles are determined. We identified the NEAT1_2 RNA domains responsible for shell localization of the NEAT1_2 ends, which determine the characteristic internal organization. We then applied a theoretical framework using soft matter physics to understand the principles that determine the NEAT1_2 organization, shape, number, and size of paraspeckles. By treating paraspeckles as amphipathic block copolymer micelles, we could explain and predict the experimentally observed behaviors of paraspeckles upon NEAT1_2 domain deletions or transcriptional modulation. Thus, we propose that paraspeckles are block copolymer micelles assembled through microphase separation. This work provides an experimentally-based theoretical framework for the concept that ribonucleoprotein complexes (RNPs) can act as block copolymers to form RNA-scaffolding microphase-separated condensates in cells.

Kleman, M., Lavrentovich, O.D.: Soft Matter Physics. An Introduction

2004 ◽  
Vol 27 (3-4) ◽  
pp. 563-564 ◽  
Author(s):  
K. M. Salikhov
Keyword(s):  
Soft Matter ◽  
Soft Matter Physics

scholarly journals Topology control of human fibroblast cells monolayer by liquid crystal elastomer

2020 ◽  
Vol 6 (20) ◽  
pp. eaaz6485 ◽  
Author(s):  
Taras Turiv ◽  
Jess Krieger ◽  
Greta Babakhanova ◽  
Hao Yu ◽  
Sergij V. Shiyanovskii ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Orientational Order ◽  
Topological Defects ◽  
Density Fluctuations ◽  
Dermal Fibroblasts ◽  
Produce Cell ◽  
Surface Anchoring ◽  
Liquid Crystal Elastomer ◽  
Anisotropic Surface ◽  
Living Tissues

Eukaryotic cells in living tissues form dynamic patterns with spatially varying orientational order that affects important physiological processes such as apoptosis and cell migration. The challenge is how to impart a predesigned map of orientational order onto a growing tissue. Here, we demonstrate an approach to produce cell monolayers of human dermal fibroblasts with predesigned orientational patterns and topological defects using a photoaligned liquid crystal elastomer (LCE) that swells anisotropically in an aqueous medium. The patterns inscribed into the LCE are replicated by the tissue monolayer and cause a strong spatial variation of cells phenotype, their surface density, and number density fluctuations. Unbinding dynamics of defect pairs intrinsic to active matter is suppressed by anisotropic surface anchoring allowing the estimation of the elastic characteristics of the tissues. The demonstrated patterned LCE approach has potential to control the collective behavior of cells in living tissues, cell differentiation, and tissue morphogenesis.

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