Synthesis and Properties of Polyaniline Derivatives with Liquid Crystallinity
摘要:
Polyanilines with liquid crystalline (LC) substituents, which consist of a flexible methylene spacer and phenylcyclohexyl moiety as a mesogenic core, were synthesized. Polymerizations were performed using ammonium persulfate and perchloric acid as the catalytic system. The polymers were quite soluble in organic solvents such as THF and chloroform. The polymers were characterized by IR, UV-vis, H-1 NMR, and C-13 NMR spectroscopies. The oxidized form of the pristine polyaniline derivative with a liquid crystalline group and neutral form prepared by ammonia treatment were examined with respect to the liquid crystallinity. The polymers with the longer flexible methylene spacer (n = 10) of the oxidized form and neutral form exhibited thermotropic liquid crystallinity. Phase transitions and the corresponding enthalpy changes were evaluated using differential scanning calorimeter measurements. The smectic liquid crystallinity was characterized by fan-shaped texture through polarizing optical microscope observations. The LC domains of polyaniline derivative were growing like strings and aligned parallel to the magnetic field.
Asymmetric Electrochemical Polymerization: Preparation of Polybithiophene in a Chiral Nematic Liquid Crystal Field and Optically Active Electrochromism
作者:Hiromasa Goto、Kazuo Akagi
DOI:10.1021/ma048505n
日期:2005.2.1
polybithiophene is successfully prepared by electrochemical polymerization in a chiral nematic liquidcrystal field. Polarizing and phase-contrast optical micrographs of the polymer reveal a well-resolved spiral morphology similar to the optical texture of the chiral nematic phase. Circular dichroism measurements indicate the Cotton effect for the film. The polymer exhibits optically active electrochromism and switching
Organization of imidazolium ionic liquids into 2D ion-conductive pathways enhances the ionic conductivity of the imidazolium-based ionic liquid crystals.
Helical Nylons and Polyphthalamides Synthesized by Chiral Interfacial Polymerizations between Chiral Nematic Liquid Crystal and Water Layers
作者:Jinwoo Park、Munju Goh、Kazuo Akagi
DOI:10.1021/ma500515s
日期:2014.5.13
enable the synthesis of both helical aliphatic polyamide (nylon) and aromatic polyamide (polyphthalamide) and can control their spiral morphologies. In this study, we developed a novel polymerization method based on chiral interfacial polycondensation using a chiral nematic liquid crystal (N*-LC) layer and a water layer and, for the first time, succeeded in synthesizing helical nylons and polyphthalamides
Synthesis of Liquid Crystalline Binaphthyl Derivatives
作者:Katsuhiko Kanazawa、Isao Higuchi、Kazuo Akagi
DOI:10.1080/10587250108025054
日期:2001.8
We present the first liquid crystalline (LC) binaphthyl derivatives, in which the rigid rod-like substituents containing phenylcyclohexyl mesogenic cores are introduced into the 2, 2', 6, and 6' positions of the chiral binaphthyl rings. The binaphthyl derivatives show enantiotropic smectic A phase, but neither chiral nematic nor chiral smectic phase. The present quadri-substituted binaphthyl derivatives gave larger values in twisting power (PM), compared with the non-substituted and di-substituted binaphthyl derivatives.