The Role of Solution Phase Water on the Deposition of Thin Films of Poly(vinylidene fluoride)
Marcel Benz, William B. Euler*, and Otto J. Gregory, Macromolecules, 2002, 35, 2682-2688.
Abstract
Thin films of PVDF were deposited from a variety of solution conditions and
examined by IR spectroscopy and scanning electron microscopy. Methods to rapidly assess the film thickness
and the phase composition of PVDF films have been developed. In particular, the formation of the ferroelectric
phase can be controlled by the composition of the solvent, notably the water
content. Using a hydrated salt in the casting solvent reproducibly formed films with high
phase content. However, the water also induces increased surface roughness in the deposited films. The nature
of the PVDF films also is influenced by the kinetics of the evaporation process, and this was followed by IR spectroscopy.
The rate constants depend upon both the film thickness and the gas-phase humidity, indicating that solvent diffusion
is an important contributor to both the bulk phase composition and the surface structure of the polymer films.