A systematic study was carried out to investigate the effect of solvent type and temperature on the formation of the alpha and beta phases from solution cast PVDF. Three solvents with different boiling points were used: N,N, dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP) and hexa methyl phosphoramide (HMPA). Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed that the type of phase formed depends on the crystallization rate of PVDF, which in turn is determined by the evaporation rate of the solvent. Low rates result predominantly in the trans-planar beta phase, high rates predominantly in the trans-gauche alpha phase and intermediate rates in a mixture of these two phases, regardless of solvent and temperature used. Since evaporation rate of the solvent is intimately related to temperature, PVDF films can be obtained predominantly in either one of these phases, or a mixture of these, by an adequate choice of the evaporation temperature range for a given solvent. The possible solubility curves of the two polymorphs alpha and beta of PVDF were sketched. The formation of different types of spherulites, associated with the two different PVDF polymorphs, could be verified by surface micrographs of the cast films. (C) 2008 Elsevier Ltd. All rights reserved.