Polymerization of Langmuir-Blodgett films of diacetylenes

Monolayer and multilayer assemblies of Langmuir-Blodgett films of 10-12 pen tacosadyinoic acid (12-8 diacetylene) were deposited on flat gold substrate s. Micrometre-size features were patterned by polymerization of the films b y using standard electron beam lithography. Polymerized areas on a monolaye r and bilayer, as well as multilayer films, were examined by scanning elect ron microscopy, atomic force microscopy and resonant Raman spectroscopy. It was established that polymerized areas on a monolayer and bilayer LB film adhere onto the gold substrate after development. The exposure curve, sensi tivity, contrast and resolution of the polymer have been determined by usin g atomic force microscopy and correlated with the deposition conditions and molecular parameters. Stresses induced in the organic film during polymeri zation lead to an in-plane buckling of the micrometre-size polymer structur e. A simple self-consistent theory was developed to predict critical strain and critical length of buckling. The observed effect of buckling of polyme rs might open an avenue for a wide range of important practical application s in the area of nanomechanical engineering. (C) 2000 Elsevier Science B.V. All rights reserved.