Mesophase Structure in Salt-containing Solutions and Gels of Liquid-Crystalline Cellulose Derivatives and Electrical Control of their Optical Properties

纤维素聚合物在碳水化合物骨架上具有固有的半刚性和手性，因此，它们能够在凝聚流体状态下形成胆甾型液晶相，并且通常由于可见光的选择性反射而着色。(羟丙基)纤维素(HPC)的浓水溶液表现出典型的胆甾相特征，这种聚合物溶液体系也表现出LCST类型的相图，因此在高温下变得浑浊。在本研究项目中，我们研究了1)HPC和相关多糖在含盐溶液中的介晶行为，2)制备具有胆甾型排列的聚合物凝胶和薄膜的条件，以及3)一种新的方法来控制来自纤维素衍生物的液晶度和相图特征的光学性质。以下结果值得注意：1.对于HPC/盐溶致体系，表现为…更清楚的是，胆固醇周期参数以及浊点随着添加剂盐的所谓杂化效应强度的增加而增加。然而，液晶相中的取向顺序对盐的添加不敏感，这一点从氘核磁共振研究中得到了证明。我们设计和建造。一种希望通过电刺激在HPC/盐水溶液的胆甾相变色和光学混浊度中产生动态变化的装置。对通电过程进行了定量研究，阐明了通电机理。在甲基丙烯酸酯单体/水/甲醇混合溶剂中，HPC溶液聚合成功地制备了彩色薄膜。当交联胆甾相薄膜在水盐溶液中浸泡和溶胀时，样品的颜色和浊度随共存盐的种类而变化。研究了几种相关多糖的新型网络形成和相结构。较少

Cellulosic polymers possess inherently the semirigidity and chirality in the carbohydrate backbone, and therefore, they are capable of forming a 'cholesteric' liquid-crystalline phase in a condensed fluid state and often colored due to selective reflection of visible light. Concentrated aqueous solutions of (hydroxypropyl)cellulose (HPC) exhibit such a typical cholesteric character.This polymer solution system is also known to show an LCST-type of phase diagram and therefore becomes turbid at an elevated temperature. In the present research project, we investigated 1) mesophse behavior in salt-containing solutions of HPC and related polysaccharides, 2) conditions for preparing gels and films with a cholesteric arrangement of these polymers, and 3) a new method to control the optical properties coming from the liquid crystallinity and phase diagram characteristic of cellulose derivatives. The following results are worth noting :1. For the aqueous HPC/salt lyotropic system, it was shown … More clearly that the cholesteric periodicity parameter as well as the cloud point increased with an increase in strength of a so-called chaotropic effect of the additive salts. The orientation order in the liquid crystallne phase was, nevertheless, insensitive to the salt addition, as evidenced by a deuteron NMR study.2. We designed and constructed. a device desirable to produce a dynamic variation in the cholesteric coloration and optical turbidity of the aqueous HPC/salt solutions by electrical stimulation. The electrification process was examined quantitatively to clarify the mechanism.3. Colored films were prepared successfully via polymerization of HPC solutions in a methacrylate monomer/water/methanol mixted solvent. When the crosslinked cholesteric films were immersed and swollen in aqueous salt solutions, the coloration and turbidity of the samples changed depending on the sort of the coexistent salt.4. A novel network formation and phase structure were studied for a few related polysaccharides. Less