Crystal Growth and Molecular Orientation of Organic Materials Vapor-deposited on Highly-oriented Polytetrafluoroethylene Thin Film

Polytetrafluoroethylene (PTFE) thin film used as substrates was rubbed mechanically on a glass plate. PTFE thin film was composed of a highly oriented thin layer containing a few grooves along the sliding direction. The chain axis of the PTFE macromolecules corresponding to the crystal c-axis was oriented parallel to the glass surface. Diacetylene molecules such as 4,6-decadiyn-1,10-diol-bis-(n-butoxycarbonyl-methyl-urethane) deposited on a PTFE-coated glass plate formed disk-like or rectangular crystallites along the grooves of the PTFE film. Diacetylene molecules adsorbed their side chains almost perpendicular to the substrate surface and were aligned along the chain axis of the PTFE macromolecules. By photolrradiation, diacetylene molecules were polymerized topochemically to high crystalline and uniaxially oriented polymers. In the case of copper phthalocyanlne (CuPc) film deposited on a PTFE-coated glass plate kept at 150°C, the column axes of CuPc crystal were oriented parallel to the chain axis of the PTFE macromolecules. The PTFE-coated glass plates were very useful as a substrate for uniaxially oriented growth of organic materials. The oriented growth on highly-oriented PTFE thin films was explained as graphoepitaxy. © 1994 Oxford University Press. All rights reserved.