Self-Organized Anisotropic Wrinkling of Molecularly Aligned Liquid Crystalline Polymer

Langmuir ◽  
2012 ◽  
Vol 28 (7) ◽  
pp. 3576-3582 ◽  
Author(s):  
Seock Hwan Kang ◽  
Jun-Hee Na ◽  
Sung Nam Moon ◽  
Woo Il Lee ◽  
Pil J. Yoo ◽  
...  
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Self Organized

Self-organized wrinkling of liquid crystalline polymer with plasma treatment

2018 ◽  
Vol 33 (23) ◽  
pp. 4092-4100 ◽  
Author(s):  
Jaehyun Sim ◽  
Sihwa Oh ◽  
Se-Um Kim ◽  
Kyuyoung Heo ◽  
Seung-Chul Park ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Self Organized ◽  
Image Position

Abstract

Three-Dimensional Photoreorientation of Self-Organized Azobenzene Chromophores in Liquid Crystalline Polymer Films

1999 ◽  
Vol 559 ◽  
Author(s):  
M. Han ◽  
S. Morino ◽  
K. Ichimura
Keyword(s):  
Absorption Spectroscopy ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Critical Role ◽  
Three Dimensional ◽  
Crystalline Polymer ◽  
Infrared Transmission ◽  
Self Organized ◽  
Out Of Plane ◽  
Transmission And Reflection

ABSTRACTPhoto-induced reorientational behavior of films of a liquid crystalline polymer with azobenzene side chains was studied by means of UV-Vis absorption spectroscopy and Fourier transform infrared transmission and reflection-absorption spectroscopy. The incident directions of light for photoisomerization played a critical role in the photocontrol of out-of-plane (three-dimensional) orientation of the azobenzenes in films. Tilted directions of the azobenzene residues were evaluated by using polarized UV-Vis absorption spectra. Photoreoriented states of azobenzene chromophores including photodichroism and tilted alignment were enhanced by successive annealing of photoirradiated films at temperatures close to the glass transition temperature of the polymer.

scholarly journals Self-organized wrinkling patterns of a liquid crystalline polymer in surface wetting confinement

Soft Matter ◽  
2015 ◽  
Vol 11 (24) ◽  
pp. 4788-4792 ◽  
Author(s):  
Jun-Hee Na ◽  
Se-Um Kim ◽  
Youngjoo Sohn ◽  
Sin-Doo Lee
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Surface Wetting ◽  
Self Organized ◽  
Geometrical Constraints ◽  
Curvature Elasticity ◽  
Reactive Mesogens

Self-organized wrinkling patterns were produced from a solution of reactive mesogens (RMs) in geometrical confinement. The symmetry of the geometrical constraints primarily governs the periodic wrinkling patterns of the RM in the wetting region through the relaxation of the curvature elasticity.

Induction, fixation and recovery of self-organized helical superstructures in achiral liquid crystalline polymer

2021 ◽  
Author(s):  
Tengfei Miao ◽  
Xiaoxiao Cheng ◽  
Haotian Ma ◽  
Wei Zhang ◽  
Xiulin Zhu
Keyword(s):  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Polymer System ◽  
Crystalline Polymer ◽  
Cross Linking ◽  
Self Organized

A flexible chiral storage based on an achiral polymer system can be successfully achieved by chiral doping and covalent cross-linking.

Observing the relaxation of molecular orientation in sheared liquid crystalline polymer solutions

1990 ◽  
Vol 48 (4) ◽  
pp. 1092-1093
Author(s):  
Wendy Putnam ◽  
Christopher Viney
Keyword(s):  
Molecular Orientation ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Polymer Processing ◽  
Molecular Alignment ◽  
Global Alignment ◽  
Shear Direction ◽  
Axial Strength ◽  
Strength And Stiffness

Liquid crystalline polymers (solutions or melts) can be spun into fibers and films that have a higher axial strength and stiffness than conventionally processed polymers. These superior properties are due to the spontaneous molecular extension and alignment that is characteristic of liquid crystalline phases. Much of the effort in processing conventional polymers goes into extending and aligning the chains, while, in liquid crystalline polymer processing, the primary microstructural rearrangement involves converting local molecular alignment into global molecular alignment. Unfortunately, the global alignment introduced by processing relaxes quickly upon cessation of shear, and the molecular orientation develops a periodic misalignment relative to the shear direction. The axial strength and stiffness are reduced by this relaxation.Clearly there is a need to solidify the liquid crystalline state (i.e. remove heat or solvent) before significant relaxation occurs. Several researchers have observed this relaxation, mainly in solutions of hydroxypropyl cellulose (HPC) because they are lyotropic under ambient conditions.

Phase Separation in Liquid-Crystalline Copolymer/Poly(methyl methacrylate) Blends

1995 ◽  
Vol 60 (11) ◽  
pp. 1869-1874 ◽  
Author(s):  
Anatoly E. Nesterov ◽  
Yuri S. Lipatov ◽  
Vitaly V. Horichko
Keyword(s):  
Phase Separation ◽  
Methyl Methacrylate ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Ethylene Terephthalate ◽  
Crystalline Polymer ◽  
Scattering Method ◽  
Thermally Induced ◽  
Poly Methyl Methacrylate ◽  
Copolymer Poly

The phase separation in the blends of poly(methyl methacrylate) and liquid-crystalline polymer (copolymer of ethylene terephthalate and p-hydroxybenzoic acid) has been studied by the light scattering method and the cloud point curves have been obtained. Simultaneously some morphological features of the blends have been observed. It was found that the initial blends are in the state of forced compatibility and that thermally induced phase separation occurs by the mechanism of spinodal decomposition but presumably in the non-linear regime.

scholarly journals Fiber Formation and Structural Development of HBA/HNA Thermotropic Liquid Crystalline Polymer in High-Speed Melt Spinning

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Bo Seok Song ◽  
Jun Young Lee ◽  
Sun Hwa Jang ◽  
Wan-Gyu Hahm
Keyword(s):  
Mechanical Properties ◽  
Shear Rate ◽  
High Speed ◽  
Melt Spinning ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Fiber Formation ◽  
Structural Development ◽  
Thermotropic Liquid Crystalline Polymer

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.

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