Novel main-chain liquid crystalline Diels-Alderdynamic networks (LCDANs) were prepared that exhibit unprecedented ease for actuator programming and reprocessing compared to existing liquid crystalline network (LCN) systems. Following cooling from 125 °C, LCDANs are deformed with aligned mesogens self-locked at roomtemperature by slowly formed Diels-Alder (DA) bonds, which allows for the formation
Selective Decrosslinking in Liquid Crystal Polymer Actuators for Optical Reconfiguration of Origami and Light‐Fueled Locomotion
作者:Zhi‐Chao Jiang、Yao‐Yu Xiao、Xia Tong、Yue Zhao
DOI:10.1002/anie.201900470
日期:2019.4.8
The ability to optically reconfigure an existing actuator of a liquidcrystalpolymer network (LCN) so that it can display a new actuation behavior or function is highly desired in developing materials for soft robotics applications. Demonstrated here is a powerful approach relying on selectivepolymer chain decrosslinking in a LCN actuator with uniaxial LC alignment. Using an anthracene‐containing
LIQUID CRYSTALLINE ELASTOMER PRECURSOR AND LIQUID CRYSTALLINE ELASTOMER
申请人:TOYO TIRE & RUBBER CO., LTD.
公开号:US20190062487A1
公开(公告)日:2019-02-28
Provided is a novel liquid crystalline elastomer that can reversibly undergo phase transition between a liquid crystalline phase and an isotropic phase thereof in a relatively low temperature region. A liquid crystalline elastomer precursor comprising a mesogenic group to which an oxide compound is attached, wherein the liquid crystalline elastomer precursor has a molecular moiety excluding the mesogenic group, the molecular moiety having at least one ester bond and at least two active hydrogen groups. A liquid crystalline elastomer comprising the liquid crystalline elastomer precursor cross-linked by a trifunctional or higher-functional isocyanate compound and/or polyol compound, wherein the liquid crystalline elastomer has a molecular moiety excluding the mesogenic group, the molecular moiety having at least one ester bond, and the liquid crystalline elastomer reversibly changes a state thereof between a liquid crystalline phase and isotropic phase thereof in response to a change in temperature thereof.
Fabrication and characterization of imprinted photonic crystalline polymer matrices via multiple UV polymerizations
作者:Chih-Chieh Chien、Jui-Hsiang Liu、A. V. Emelyanenko
DOI:10.1039/c2jm35151j
日期:——
A photonic polymer network was imprinted using multiple UV-induced polymerizations in the presence of cholesteric liquid crystals (CLCs). Here, the imprinted polymer matrices provided a chiral environment due to the chirality of the polymer networks. The fabricated cell exhibited Bragg reflections even in the absence of anisotropic materials. Moreover, a phototunable liquid crystal cell was fabricated with photosensitive liquid crystalline ethyl 4-[4-(11-acryloyloxy undecyloxy) phenyl azobenzoyl-oxyl] benzoate. The tuning properties of the cells were examined as a function of the irradiation time and concentration of the photosensitive material. Both the tuning rate and dark relaxation of E–Z photoisomerization of the embedded LCs in the polymer network were also examined.
Guidelines To Creating a True Molecular Composite: Inducing Miscibility in Blends by Optimizing Intermolecular Hydrogen Bonding
作者:Sriram Viswanathan、Mark D. Dadmun
DOI:10.1021/ma011031x
日期:2002.6.1
amount of intermolecularhydrogenbonding between the two polymers and DSC and optical microscopy to determine the phase behavior of these blends, the results demonstrate that the broadest miscibility window in the blends studied corresponds to the system that optimizes the extent of intermolecularhydrogenbonding. Moreover, the system that maximizes the extent of intermolecularhydrogenbonding is one