ULTRA-THIN FILMS OF POLY(O-ETHOXYANILINE) FORMED FROM DOPED MONOLAYERS

The effect of pH and type of doping acid on monolayer behavior is inve stigated for poly(o-ethoxyaniline). Doping during monolayer formation is essential for high-quality Langmuir-Blodgett (LB) films to be obtai ned. Langmuir films were spread on a variety of subphases, containing trifluoroacetic, hydrochloric, sulfuric or perchloric acids at differe nt concentrations. Doping of the polymer occurs at pH values lower tha n 3 when spreading of the solution is improved. Pressure-area isotherm s display less hysteresis and higher collapse pressures when the polym er is pre-doped and spread on a pH = 1 subphase. Under these condition s monolayers could be transferred from the aqueous subphase onto hydro philic substrates in the form of Z-type LB films.