PREPARATION OF PURE Y-TYPE LANGMUIR-BLODGETT-FILMS OF LEAD STEARATE AND THEIR REACTION WITH HYDROGEN-SULFIDE

Higher residual PbCl2 concentration was found within lead stearate (Pb St2) Langmuir-Blodgett (LB) films deposited on the surface of 10(-3) m ol l-1 PbCl2 aqueous solution. LB films with an acceptable composition can be obtained in the case of lower PbCl2 concentrations (less than 5 x 10(-4) mol l-1). A pure Y-type transfer form for PbSt, LB films wa s observed on a subphase with a lower PbCl2 concentration as a result of using a faster dipping speed (10 cm min-1). Using X-ray diffraction measurements, it was determined that the pure Y-type PbSt2 LB films p ossess a certain number of layers which is the same as the value recor ded during the deposition period. The rate of the chemical reaction of the pure Y-type PbSt2 LB films with H2S was found to be at least one order of magnitude slower than that in the case of the PbSt2 LB films deposited at the lower dipping speed.