Thermomechanical properties of monodomain nematic main-chain liquid crystal elastomers

Soft Matter ◽  
2018 ◽  
Vol 14 (29) ◽  
pp. 6024-6036 ◽  
Author(s):  
Daniel R. Merkel ◽  
Nicholas A. Traugutt ◽  
Rayshan Visvanathan ◽  
Christopher M. Yakacki ◽  
Carl P. Frick
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Reaction Scheme ◽  
Thermomechanical Properties ◽  
Two Stage ◽  
Liquid Crystal Elastomers

Actuation temperature was controlled without influencing total actuation performance in liquid crystal elastomers fabricated by a two-stage reaction scheme.

Microscopy of Diffuse Nematic–Isotropic Transition in Main-Chain Nematic Liquid-Crystal Elastomers

2021 ◽  
Vol 54 (8) ◽  
pp. 3678-3688
Author(s):  
Takuya Ohzono ◽  
Kaoru Katoh ◽  
Eugene M. Terentjev
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Main Chain ◽  
Liquid Crystal Elastomers

Effect of stretching angle on the stress plateau behavior of main-chain liquid crystal elastomers

Soft Matter ◽  
2021 ◽  
Vol 17 (11) ◽  
pp. 3128-3136
Author(s):  
Suzuka Okamoto ◽  
Shinichi Sakurai ◽  
Kenji Urayama
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Stress Plateau ◽  
Liquid Crystal Elastomer ◽  
Ultimate Elongation ◽  
Liquid Crystal Elastomers

Stretching angle for a main-chain liquid crystal elastomer has pronounced effects on the width of the stress plateau as well as the ultimate elongation, while it has no effect on the plateau height.

Main-chain liquid-crystal elastomers versus side-chain liquid-crystal elastomers: similarities and differences in their mechanical properties

Soft Matter ◽  
2018 ◽  
Vol 14 (31) ◽  
pp. 6449-6462 ◽  
Author(s):  
D. Rogez ◽  
S. Krause ◽  
P. Martinoty
Keyword(s):  
Mechanical Properties ◽  
Liquid Crystal ◽  
Main Chain ◽  
Poisson Ratio ◽  
Side Chain ◽  
Similarities And Differences ◽  
Liquid Crystal Elastomers

The shear and Young moduli, the poly-domain to mono-domain transition, the Poisson ratio and the supercritical or subcritical nature of main-chain and side-chain liquid-crystal elastomers are characterized with various mechanical experiments.

Unsymmetric main-chain liquid crystal elastomers with tunable phase behaviour: elastic response

2011 ◽  
Vol 21 (23) ◽  
pp. 8436 ◽  
Author(s):  
Maria Amela-Cortés ◽  
Duncan W. Bruce ◽  
Kenneth E. Evans ◽  
Christopher W. Smith
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Phase Behaviour ◽  
Elastic Response ◽  
Liquid Crystal Elastomers

Unsymmetric main-chain liquid crystal elastomers with tuneable phase behaviour: synthesis and mesomorphism

2011 ◽  
Vol 21 (23) ◽  
pp. 8427 ◽  
Author(s):  
Maria Amela-Cortés ◽  
Benoît Heinrîch ◽  
Bertrand Donnio ◽  
Kenneth E. Evans ◽  
Chris W. Smith ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Phase Behaviour ◽  
Liquid Crystal Elastomers

Experimental Studies of Thermo-Induced Mechanical Effects in the Main-Chain Liquid Crystal Elastomers

2014 ◽  
Vol 896 ◽  
pp. 322-326 ◽  
Author(s):  
Supardi ◽  
Harsojo ◽  
Yusril Yusuf
Keyword(s):  
Liquid Crystal ◽  
Critical Temperature ◽  
Main Chain ◽  
Experimental Studies ◽  
Artificial Muscles ◽  
Direction Parallel ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Heating Up ◽  
Contraction And Expansion

Liquid crystal elastomers (LCEs), either side-chain LCEs (SCLCEs) or main-chain LCEs (MCLCEs), possess a combination of LC and elastic properties, and are expected to be used as artificial muscles. We experimentally investigated the thermo-induced mechanical effects showed by MCLCEs with four different crosslinker concentrations, i.e., 8%, 12%, 14% and 16%. The samples were heated up to the critical temperature and the images were recorded. The samples made the contraction in direction parallel to the director and the expansion in direction perpendicular to the director. Drastic changes occured when approaching the critical temperature, the greater the crosslinkers concentration the bigger the maximum contraction and expansion. The shape anisotropy expression showed that heating up to the critical temperature caused the system no longer in anisotropic state.

Characterization of Main-Chain Liquid Crystal Elastomers by Using Differential Scanning Calorimetry (DSC) Method

2015 ◽  
Vol 1123 ◽  
pp. 69-72 ◽  
Author(s):  
Supardi ◽  
Y. Yusuf ◽  
Harsoyo
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Basic Principle ◽  
Main Chain ◽  
Scanning Calorimetry ◽  
Mechanical Effects ◽  
Liquid Crystal Elastomers ◽  
Dsc Method

We performed an experiment to characterize the four samples of main chain liquid crystal elastomers (MCLCEs) by using differential scanning calorimetry (DSC) method. Basic principle of this method is that difference in the amount of heat required to increase the temperature of the sample and reference is measured as a function of temperature. The temperature between the sample and reference is maintained nearly the same throughout the experiment. There were four samples with different concentrations of crosslinker we have taken, namely 8%, 12%, 14%, and 16%. The results showed that the phase transition from nematic to isotropic obtained by this method had correlation with their thermo-mechanical effects.

Artificial muscles based on liquid crystal elastomers

2006 ◽  
Vol 364 (1847) ◽  
pp. 2763-2777 ◽  
Author(s):  
Min-Hui Li ◽  
Patrick Keller
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Uv Light ◽  
Shape Change ◽  
Artificial Muscle ◽  
Isotropic Phase ◽  
Artificial Muscles ◽  
Stimuli Responsive ◽  
Liquid Crystal Elastomers ◽  
The Individual

This paper presents our results on liquid crystal (LC) elastomers as artificial muscle, based on the ideas proposed by de Gennes. In the theoretical model, the material consists of a repeated series of main-chain nematic LC polymer blocks, N, and conventional rubber blocks, R, based on the lamellar phase of a triblock copolymer RNR. The motor for the contraction is the reversible macromolecular shape change of the chain, from stretched to spherical, that occurs at the nematic-to-isotropic phase transition in the main-chain nematic LC polymers. We first developed a new kind of muscle-like material based on a network of side-on nematic LC homopolymers. Side-on LC polymers were used instead of main-chain LC polymers for synthetic reasons. The first example of these materials was thermo-responsive, with a typical contraction of around 35–45% and a generated force of around 210 kPa. Subsequently, a photo-responsive material was developed, with a fast photochemically induced contraction of around 20%, triggered by UV light. We then succeeded in preparing a thermo-responsive artificial muscle, RNR, with lamellar structure, using a side-on nematic LC polymer as N block. Micrometre-sized artificial muscles were also prepared. This paper illustrates the bottom-up design of stimuli-responsive materials, in which the overall material response reflects the individual macromolecular response, using LC polymer as building block.

scholarly journals Viscoelasticity of the polydomain-monodomain transition in main-chain liquid crystal elastomers

Polymer ◽  
2016 ◽  
Vol 98 ◽  
pp. 165-171 ◽  
Author(s):  
A. Azoug ◽  
V. Vasconcellos ◽  
J. Dooling ◽  
M. Saed ◽  
C.M. Yakacki ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Main Chain ◽  
Liquid Crystal Elastomers

A copper(i)-catalyzed azide–alkyne click chemistry approach towards multifunctional two-way shape-memory actuators

2020 ◽  
Vol 11 (22) ◽  
pp. 3747-3755
Author(s):  
Zhong-Cheng Liu ◽  
Bo Zuo ◽  
Hai-Feng Lu ◽  
Meng Wang ◽  
Shuai Huang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Shape Memory ◽  
Click Chemistry ◽  
Main Chain ◽  
Shape Memory Actuators ◽  
Liquid Crystal Elastomers

Here we report a copper(i)-catalyzed azide–alkyne click chemistry approach towards the fabrication of main chain liquid crystal elastomers.

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