The surface structure of a three-layer Langmuir-Blodgett film of comblike rigid-chain polyimide prepolymer (polyamic acid alkylammonium salt) has been studied by atomic force microscopy (AFM). The AFM data reveal the presence of supramolecular formations consisting of two-dimensional domains in which aliphatic chains of the prepolymer macromolecules are oriented perpendicularly to the substrate. A mechanism responsible for the supramolecular structure formation in the film is proposed.

Atomic-force microscopy, reflectometry, and ellipsometry were applied to analysis of ultrathin films (3.3–13.6 nm) of a rigid-chain polyimide, formed on the surface of a silicon substrate by thermal imidization of Langmuir-Blodgett films of polyamido acid derived from 3,3′,4,4′-diphenyltetracarboxylic acid and ortho-tolidine.