The Influence of Preparation Conditions on the Surface Morphology of Poly(vinylidene fluoride) Films

Abstract

The α phase (or form II) of poly(vinylidene fluoride), PVF2, produced from an acetone/N,N-dimethylformamide (DMF) solution gave different surface morphologies, depending on the solvation temperature of the PVF2 solution, the DMF concentration, and the relative humidity when deposited onto a smooth silicon substrate. Solutions prepared at less than 30 °C always gave rise to transparent films. However, solutions prepared at temperatures greater than 50 °C resulted in a rough and opaque, white surface when depositing at high humidity and in a transparent film when depositing at low humidity. The aging behavior of the polymer solutions as measured by the viscosity revealed an enormous dependence on the DMF concentration. Optical light and atomic force microscopies and infrared spectroscopy characterized the differences of these film surfaces.

Effect of solvents on morphology and polymorphism of polyvinylidene fluoride membrane via supercritical CO2 induced phase separation

“…It was found that dipolar interaction at interface between PVDF nucleus and solvent molecules can preferably lead to trans conformation packing of CH 2 ACF 2 dipoles, thus b phase is formed during crystallization. 35,36 Dipole moments of the four solvents used in our experiment were listed in Table I. According to this theory, the content of b phase in above four systems should decrease in the same order as the polarity variation: M-DMF > M-D7T3 > M-D5T5 > M-TEP.…”

Localized Pressure‐Induced Ferroelectric Pattern Arrays of Semicrystalline Poly(vinylidene fluoride) by Microimprinting

“…PVDF pellets were dissolved in dimethylformamide (DMF). Thin films were formed by spin-coating a 1-10 % solution at 15 % humidity on Al and Si substrates [30]. Film thickness ranged from 70 nm to 2 lm, confirmed by using cross-sectional SEM.…”

Film Growth and Surface Roughness with Effective Fluctuating Covalent Bonds in Evaporating Aqueous Solution of Reactive Hydrophobic and Polar Groups: A Computer Simulation Model

“…This is in contrast to previous studies [18] where the interface continues to decay with the temperature. Now let us examine what happens on including more interaction among mobile functional groups, i.e., the interaction Equation (1)- (4). As show in Figure 3, the variation of the mean surface height of the film, h, with time remains nearly the same as the system with the hardcore interaction alone (see Figure 1) at higher temperature.…”