Rheology and Optical Properties of Thermotropic Liquid Crystalline Polymers

热致液晶聚合物（TLCP）的新应用目前由于缺乏对液晶状态和凝固过程（向晶体状态转变）的结构形成过程的理解而受到阻碍。这样的理解是控制机械、电气和光学性质所必需的，这些性质不仅取决于内在的分子性质，而且取决于大规模的结构。本研究涉及对tlcp在流变和磁场下的结构进行合作研究。光散射和显微镜（R.S. Stein）和流变学（H.H. Winter）将应用于特定合成的样品（宝丽来），并利用实验室的磁场来创建必要的校准。通过施加明确定义的机械和电场，可以产生中间的织构状态。对场诱导单畴的研究将给出理解多畴行为所需要的本征性质（Miesowicz粘、Frank弹性常数）。将研究自然多域和中间偏析密度，为实际应用（设计合适的加工设备）以及多域tlcp的理论描述奠定基础。

Novel applications of thermotropic liquid crystalline polymers (TLCP) are currently prevented by the lack of understanding of the structure formation processes in the liquid crystalline state and during solidification (transition to the crystal state). Such understanding is required for controlling mechanical, electrical, and optical properties which not only depend on the intrinsic molecular properties but also on the large-scale texture. This research involves a cooperative study of the structuring of TLCPs in rheological and magnetic fields. Light scattering and microscopy (R.S. Stein) and rheology (H.H. Winter) will be applied to specifically synthesized samples (Polaroid) and the magnetic field of a laboratory will be utilized to create the necessary alignment. Intermediate textural states will be produced by applying well-defined mechanical and electrical fields. The study of the field induced monodomain will give the intrinsic properties (Miesowicz viscosities, Frank elastic constants) which are needed to understand the behavior of polydomains. The natural polydomain and intermediate disclination densities will be studied to lay the foundation for practical applications (design of suitable processing equipment) as well as for a theoretical description of polydomain TLCPs.