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本文利用 Abbe’折射仪和热台偏光显微镜研究了氰乙基纤维素/二甲基乙酰胺液晶溶液的形成、结构和某些性质。它与许多溶致性液晶一样,随溶液浓度的增加,溶液从各向同性状态经过两相共存状态转变成为单一的液晶态。溶液的双折射△n 随浓度增加而增加,随温度的升高而降低。升温速率的改变对测定临界温度值有一定的影响。液晶相在无外力作用时由许多取向的、无规分布的微区域组成。受到切应力后,微区变成长条状。分子链沿切应力方向取向,并在垂直于切应力方向上在各微区域内排列有序,相邻两微区的分子链的取向方向稍有不同。
In this paper, the formation, structure and some properties of cyanoethyl cellulose / dimethylacetamide liquid crystal solution were studied by Abbe ’refractometer and hot stage polarization microscope. Like many lyotropic liquid crystals, it changes from an isotropic state through a two-phase coexistence state to a single liquid crystalline state as the solution concentration increases. The birefringence △ n of the solution increases with increasing concentration and decreases with increasing temperature. Changes in heating rate have a certain impact on the determination of the critical temperature. The liquid crystal phase is composed of many oriented, randomly distributed micro-regions in the absence of external forces. After being subjected to shear stress, the microdomains become long strips. The molecular chains are oriented along the direction of shear stress and are arranged in each micro-area perpendicular to the direction of shear stress. The orientations of the molecular chains in two adjacent micro-domains are slightly different.