Growth Mechanism of Polydiacetylene Monolayer at the Air-Water Interface

采用原位观察的方法研究了双乙炔单分子膜在空气-水界面上的形态变化。表面形貌随涂布液浓度和涂布面面积的变化而变化。通过扩散相对高浓度的溶液，获得了直径达1mm的二维螺旋结构。将高浓度溶液涂抹在有界的小水面上，通过移动屏障缓慢增加水面面积，制备出取向均匀的大于20mm×5mm的大单晶畴。一种新型的检测系统能够从界面处的聚二乙炔单分子层的共轭链上观察到偏振荧光。在空气和氩气气氛下记录了紫外辐照聚合过程中单层膜的表面结构。在氩气气氛中，表面形貌在聚合过程中保持不变。另一方面，在氧气（空气）存在的情况下，在单晶胞中发现了很大的变形。

Morphological variation of diacetylene monolayers was investigated by in-situ observation at the air-water interface. The surface morphology changes with concentration of the spreading solution and area of the spreading surface. Two dimensional spiral structures with a diameter as large as 1 mm were obtained by spreading a solution of relatively high concentration. Uniformly oriented large single crystal domains of over 20mm×5mm were prepared when the area of the water surface was slowly increased by moving a barrier after a highly concentrated solution was spread on a small bounded water surface. A novel detection system enabled the observation of polarized fluorescence from the conjugated chains of the polydiaeetylene monolayer at the interface Long range ordering m the conjugated polymer chains persists along one direction throughout a domain. The surface structure of the monolayer during the polymerization process by UV irradiation was recorded in both air and argon atmospheres. In the argon atmosphere, the surface morphology remains constant during polymerization. On the other hand, a large deformation was found in the unit cell in the presence of oxygen (air).