Surface analysis of poly(vinylidene difluoride) membranes

Commercially available poly(vinylidene difluoride) (PVDF) membranes are offered with hydrophilic and hydrophobic surfaces. The differences between these modifications at the surface were studied by X-ray photoelectron spectroscopy (XPS or ESCA), Fourier transform infrared spectroscopy (FTIR), and secondary ion mass spectroscopy (SIMS). Between the two membrane types significant differences in the surface chemistry were observed. During X-ray irradiation, required for XPS, degradation effects of the PVDF membranes occurred. Changes in shape, intensity, and energy position of the different element emissions were used to characterize the structural modifications and the kinetics of the X-ray induced degradation.