POLYMER-CHAIN STRUCTURE OF POLYIMIDE LANGMUIR-BLODGETT-FILMS DETERMINED BY ATOMIC-FORCE MICROSCOPY

We applied atomic force microscopy (AFM) to investigate the microscopic molecular structures of polyimide Langmuir-Blodgett (LB) films. Polyimide chains of a monolayer film on graphite were observed. We found that a polyimide LB film with a groovy surface occurs due to orientation of polyimide chains, which have a well-ordered structure. For horizontal deposition, the polyimide chains show a zigzag structure, while for vertical deposition, the polyimide chains show a straight-line structure. Moreover, the polyimide chains are always oriented along the direction of deposition. We suggest that the polyimide chain orientation is induced by the LB dipping process.