Formation and Orientation Studies of a Z-Type Polymeric Langmuir-Blodgett Film.

Langmuir-Blodgettfilms of poly(acrylonitrile-co-4-vinylpyridine) were assembled on quartz and calcium fluoride substrates from a preformed monolayer on water. The observed transfer ratios indicated z-type deposition. Infrared spectroscopic measurements in the transmission mode revealed a linear dependence of the nitrile absorbance as a function of the number of layers deposited. Polarized infrared spectroscopy was used to semiquantitatively determine the average chain orientation in the film. Calculations of dichroic ratios indicate that the chains lie relatively flat on the substrate surface. Polarized ultraviolet spectroscopy was also utilized to determine the orientation of the pyridine headgroups in the LB film, and the calculations indicated a pyridine tilt angle of approximately 19 degrees to the film surface. Copyright 1999 Academic Press.