Study on Molecular Orientation Effects in Polymer-Liquid Crystal Composite Systems

以各种紫外光固化甲基丙烯酸酯预聚体和介电各向异性正负向列型液晶制备聚合物-液晶复合材料，简称PDLC(聚合物分散液晶)。PDLC单元可以从光散射关闭状态电切换到高度透明的开启状态。在具有相反形态的PDLC单元中观察到记忆效应，其中在移除电压后透明保持很长时间。在施加电场或磁场的情况下，通过从各向同性相到向列相的相变可以容易地产生记忆状态。对其电光和热光性能进行了研究，并通过扫描电子显微镜观察了PDLC薄膜的形貌，测量和讨论了聚合条件和相分离条件对其形貌和电光性能的影响。…制备人牙周膜细胞在不同的紫外光照射条件下，测量了薄膜的透过率、电容和电阻，同时进行了相分离。通过监测光电阻值的变化，可以明确紫外光照射时间与电光性能之间的关系，从而获得制备它们的最佳条件。提出了一种新型的光学器件，该器件在关断状态下只沿与电池法线成斜角的方向传输入射光，采用正负型PDLC电池，在相对较低的驱动电压下获得了高度透明的存储状态。在正模式和负模式下使用激光在PDLC单元上执行热寻址和局部擦除。用热敏打印机头成功地将热像写入柔性PDLC薄膜上，讨论并论证了聚合物-液体晶体复合材料在新型热寻址显示器件中应用的可能性。较少

Polymer-liquid crystal composite materials abbreviated by PDLC (polymer dispersed liquid crystals) are prepared using various kinds of UV-curable methacrylate prepolymer and nematic liquid crystals with a positive or a negative dielectric anisotropy. The PDLC cells can be switched electrically from a light scattering off state to a highly transparent on state. Memory effects, in which a transparency is preserved for a long time after a voltage is removed, are observed in PDLC cells with a reversed morphology. The memory states can easily created by the phase transitions from an isotropic to a nematic phase with application of an electric or a magnetic field. Their electrooptical and thermo-optical properties are studied.Morphologies of PDLC films are studied by scanning electron microscope photographs of their sections, and the dependence of polymerization and phase separation conditions on the morphology and electrooptical properties are measured and discussed. PDLC cells are prepared … More with various terms of UV irradiation, and the transmittance, capacitance and resistance are measured while the phase separation is advanced. The relationship between the term of UV irradiation and the electrooptical property can be clarified and the optimum condition to prepare them can be attained by monitoring the change of the resistance.A new type of optical device which transmits the incident light only in directions oblique to the normal of the cell in an off-state is demonstrated using both the positive-type and negative-type PDLC cells.Ad highly transparent memory-state was obtained with relatively low driving voltage. Thermal addressing and local erasure in the positive and negative modes were performed using a laser beam on the PDLC cell. A thermal image was also succesfully written by a thermall printer head onto a flexibele PDLC film.The possibility of application of the polymer-liquid crystaal composites to the new type of thermally addressed display device is discussed and demonstraated. Less