Formation and orientation studies of a Z-type polymeric Langmuir-Blodgett film

Langmuir-Blodgett films of poly(acrylonitrile-co-4-vinylpyridine) were asse mbled on quartz and calcium fluoride substrates from a preformed monolayer on water. The observed transfer ratios indicated z-type deposition. Infrare d spectroscopic measurements in the transmission mode revealed a linear dep endence of the nitrile absorbance as a function of the number of layers dep osited, Polarized infrared spectroscopy was used to:semiquantitatively dete rmine the average chain orientation in the film. Calculations of dichroic r atios indicate that the chains lie relatively flat on the substrate surface . Polarized ultraviolet spectroscopy was also utilized to determine the ori entation of the pyridine headgroups in the LB him, and the calculations ind icated a pyridine tilt angle of approximately 19 degrees to the film surfac e. (C) 1999 Academic Press.