Quantitative Evaluation of Crystalline Defects in Langmuir-Blodgett Film

本研究主要探讨单分子膜与LB膜中结晶缺陷的定量评估，以及低结晶缺陷LB膜的制备。从亚相温度、Tsp对静态粘弹性的依赖性和它们的聚集结构之间的关系来评价脂肪酸单分子膜在水表面上的熔融温度Tm和结晶弛豫温度Tc。研究表明，单分子膜的表面压力-面积等温线代表了孤立微区在水面上铺展后立即形成的聚集过程。根据Tm与Tsp的关系，将单分子膜分为结晶单分子膜和非晶单分子膜。利用电子衍射技术对单层膜中的晶体缺陷D进行了测定。与结晶单层膜（D = 4%）相比，结晶单层膜（由非晶单层膜在水面上结晶得到）具有非常低的结晶缺陷值（D = 1.5%）。另一方面，在X射线衍射技术的基础上，LB膜中的晶体缺陷进行了评估。结果表明，LB膜中的晶体缺陷受制备条件的控制。这些结果对制备无晶体缺陷的LB膜具有重要的指导意义。

In this study, the quantitative evaluation of crystalline defects in monolayer and langmuir-blodgett (LB) film and the preparation of them with low crystalline defects were investigated. The melting temperature, Tm and crystalline relaxation one, T c of fatty acid monolayers on the water surface was evaluated from the relationships between the subphase temperature, Tsp dependence of static viscoelasticities and the aggregation structure of them. It was made clear that the surface pressure-area isotherm of monolayer represented the gathering process of isolated domains, which were formed right after spreading on the water surface. From the relationship between Tm and Tsp, the monolayers were classified into the crystalline one and the amorphous one. On the basis of electron diffraction technique, the crystalline defects, D in monolayer were evaluated. In comparison with crystalline monolayer (D = 4 %), the crystallized monolayer, which was obtained by the crystallization of amorphous one on the water surface, had very low value of crystalline defects (D = 1.5 %). On the other hand, the crystalline defects in LB film were evaluated on the basis of X-ray diffraction technique. It became clear that the crystalline defects in LB film were controlled by the condition of preparation. These results should be very useful for preparation of the LB film with no crystalline defect.