LANGMUIR-BLODGETT-FILMS OF POLY(O-ANISIDINE)

LB films have been fabricated by transferring poly(o-anisidine) (POA) monolayers from a pure water surface onto glass substrates using the c onventional dipping method. The chemically synthesized poly(o-anisidin e) consists of two fractions, one containing mainly octamers and anoth er of high molecular weight (around 28000 g/mol). The low weight fract ion forms condensed Langmuir monolayers which are anchored to the wate r surface through one single group, probably the metoxy-aniline, yield ing an area per molecule of ca. 20 angstrom2. The molecular configurat ion in the high-weight fraction monolayers appears to be such that one in each four or five segments of the polymer chain makes contact with the water. UV-visible spectra were obtained for the HW fraction LB fi lms which were identical to those of POA in solution, changing from da rk blue to green when the film is exposed to HCl vapour. Preliminary c onductivity measurements were carried out on these LB films showing th at the conductivity increases by three orders of magnitude upon exposu re to HCl vapour.