高分子基体/高分子网络/双稳态液晶复合材料薄膜的制备及电-光性能的研究

Bi-stable Liquid Crystals (BSLC) is a kind of cholesteric liquid crystal, which can show two stable states, transparent state with planar texture (P) and strong light scattering state with focal-conic texture (C), under certain conditions. Both the states can maintain without an electric field applied and be changed between the two states by very a little energy. Thus, BSLC materials are very energy-saving. This study is to fabricate bi-stable thin films based on epoxy resin/thiol compounds/liquid crystalline photo-polymerisable monomer (LCM)/BSLC / thermal initiator/photo-initiator mixtures. at first, the epoxy resin and the thiol compounds are cured by thermal-polymerization, and then the LCM molecules done by photo-polymerization on the condition that the BSLC is in P state. Thus, the polymer matrix/polymer networks/BSLC composite films are prepared. This study will study the methods of control the micro-structures of the polymer matrix and the networks and reveal the effects of the compositions of the films, the micro-structures of the polymer matrix and the networks, the molecular structures of the curable monomers forming the polymer matrix and the networks, the molecular structures and the compositions of the BSLC, the pitch length, the conditions of thermal-polymerization and photo-polymerization on the bi-stability and electro-optical properties of the thin films, and then provide experimental and theoretical methods for preparing energy-efficient bi-stable sunlight-shielding films.

双稳态液晶（BSLC）是一种胆甾相液晶，在一定条件下其呈透明状态的平面织构（P）和呈强烈光散射状态的焦锥织构（C）的分子排列状态都是稳定状态，不需要电场来维持，只在两种状态之间进行转换时消能极少能量，因此BSLC材料非常节能。本项目拟调制环氧树脂/硫醇化合物/液晶性光聚合单体（LCM）/BSLC/热引发剂/光引发剂混合物薄膜，首先使环氧树脂与硫醇化合物的分子间发生热聚合反应,然后在BSLC分子形成P状态的情况下使LCM分子间发生光聚合反应,制备高分子基体/高分子网络/BSLC复合材料薄膜。本项目将研究高分子基体和网络的微结构的调控方法，揭示薄膜的组成、高分子基体和网络的微观结构、构成高分子基体和网络的聚合单体的分子结构、构成BSLC的单体液晶的分子结构和组成、液晶的螺距、热和光聚合条件对薄膜的双稳态和电-光性能的影响作用和相关机理,为开发高效节能的双稳态遮阳膜提供实验方法和理论依据。

本申请项目设计制备了三个体系的双稳态液晶调光薄膜：采用聚合诱导相分离（PIPS）的方法，液晶/环氧单体/硫醇固化剂三组分材料中开发了全新的高分子微球填充液晶（简称PFLC）体系，通过在负性胆甾相液晶中构筑上述 PFLC 体系，制备了柔性双稳态调光膜。结合聚合物分散液晶（PDLC）与聚合物稳定液晶（PSLC）的制备方法，构筑了兼具PDLC与PSLC两种体系优点的聚合物分散与稳定液晶的共存体系 (a coexistent system of polymer-dispersed and polymer-stabilized liquid crystals, PD&SLC)，通过在近晶A相液晶材料中构筑上述共存体系制备了双稳态液晶调光膜。利用半刚性硫醇构筑了聚合物骨架稳定双稳态液晶复合调光薄膜。详细研究了上述双稳态调光薄膜制备工艺中各种实验材料组成和制备条件对薄膜电光性能、稳定性、力学性能等的影响，为高效节能的双稳态遮阳膜提供了系列实验方法和理论依据。