Structure and electrical properties of poly(vinyl benzoate) monolayers



The structure and electrical properties of mono- and multilayer poly(vinyl benzoate) (PVB) films have been studied by using the films as ultrathin insulating spacers between evaporated electrodes of Cu and Sn. PVB–stearic acid mixtures were also used. Form capacity measurements, autoradiographs, and the layering conditions it is concluded that the compacted PVB film on the aqueous subphase has an average area per monomer unit of ∼8A.2 and is composed of several superimposed layers of molecules rather than a single layer. Usually each transfer operation yielded a PVB insulating film whose average thickness was estimated to be ∼37 A. Under certain and still unknown conditions, the PVB layer appeared to separate on transfer to give an average film thickness of approximately half of this value. The dielectric constant of the PVB films at room temperature and 1 keycle/sec. was estimated to be ∼3.3, and was found to be frequency-dependent within the measured range of 100 cycles/sec. to 20 kcycles/sec. Conduction through the metal–PVB–metal sandwiches was highly nonlinear and was believed to take place by tunneling in the thinner films (∼20 A.) and by field-assisted thermionic emission in the thicker films (∼75 A.). Interpretation of the conduction measurements in terms of a molecular model was not possible because of the wide variations in electrical properties and lack of reproducibility.