CRYSTAL STRUCTURAL CONTROL OF ULTRA-THIN ORGANIC FILMS BY MIXING LB TECHNIQUE INTRODUCING SPACER MOLECULES

引入间隔分子的混合 LB 技术对超薄有机薄膜的晶体结构控制

基本信息

批准号：
09650020
负责人：
SHIRATORI Seimei
金额：
$ 2.18万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

Lateral spacing of the molecules in the Langumuir-Blodgett (LB) films were controlled by introducing "Spacer Molecules" such as pyrrole or fullerene (C60) molecules into arachidic acid (C20) LB films. The transformation of the molecular arrangement of C20 LB film was studied with an increase of pyrrole (py) quantity or C60 quantity which we used as guest molecules to the host molecules, C20. The change of molecular occupation area of a C20 LB films was estimated by pressure-area curves, quartz crystal microbalance method and atomic force microscopy (AFM). It was found that that a C20 LB film can contain 1.5 times as large as C20 molecules. The observation by AFM showed that the enlargement of the occupation area of C20 upon addition of spacer molecules, however, the molecules of C20 maintained the highly ordered molecular arrangement. The change of the crystal structure observed by AFM agreed well with the results of computer simulation based on molecular mechanics. The experimental and computer simulation results showed that the lattice constant of a C20 LB film is easy to control by the quantity of spacer molecules contained in the LB film.Using these characteristics, several kinds of mixed LB films, composed of C20 and C60, were prepared and the adsorption characteristics of gas molecules to these films were studied using a quartz crystal microbalance. The dependence of the amount of the gas adsorbed on the number of layers reveal that the permeability of the gas molecules into the LB films remarkably increase with an increase of the intermolecular spacing of LB films. Gas molecules with different sizes or structure were sifted by using C60 containing LB films. This characteristic of the LB films containing C60 can be applied to a novel gas sensor with a molecular sifter function.

Langumuir-Blodgett (LB) 薄膜中分子的横向间距是通过将“间隔分子”（例如吡咯或富勒烯 (C60) 分子）引入花生酸 (C20) LB 薄膜来控制的。研究了随着吡咯（py）数量或C60数量（我们用作客体分子）到主体分子C20数量的增加，C20 LB薄膜分子排列的转变。通过压力-面积曲线、石英晶体微天平法和原子力显微镜（AFM）估计了C20 LB薄膜分子占据面积的变化。研究发现，C20 LB 薄膜可含有 C20 分子的 1.5 倍大。 AFM观察表明，间隔分子的加入使C20的占据面积扩大，但C20分子保持了高度有序的分子排列。 AFM观察到的晶体结构的变化与基于分子力学的计算机模拟结果非常吻合。实验和计算机模拟结果表明，C20 LB薄膜的晶格常数很容易通过LB薄膜中所含间隔分子的数量来控制。利用这些特性，制备了几种由C20和C60组成的混合LB薄膜。制备并使用石英晶体微天平研究了气体分子对这些薄膜的吸附特性。吸附气体量对层数的依赖性表明，气体分子进入LB膜的渗透性随着LB膜分子间间距的增加而显着增加。使用含有C60的LB膜来筛选不同尺寸或结构的气体分子。含有C60的LB膜的这一特性可以应用于具有分子筛功能的新型气体传感器。