  In literature it has been reported that the gamma-phase PVDF film is formed
from dimethyl sulfoxide (DMSO) solvents regardless of preparation temperature.
In this report the crystallization of both alpha and gamma phase from DMSO
solvent by varying preparation temperature has been described. This paper also
describes the conversion of gamma-phase to beta- phase and alpha-phase at
different annealing condition. When thin films were annealed at 90C for 5
hours, then maximum beta-phase content (greater than 95%) is present in PVDF
thin film. The PVDF films completely converted to alpha-phase, when they were
annealed at 160C for 5 hours. From (X-ray diffraction) XRD, Fourier Transform
Infrared Spectrum (FTIR), (Differential thermal analysis) DTA and Raman
studies, it is confirmed that the PVDF thin films, cast from DMSO solution and
annealed at 90C for 5 hours, have maximum percentage of beta-phase(greater than
95%).
