Determination of progress in acrylic acid modification on polyvinylidene fluoride membrane by infrared spectroscopy

Filtration performances of membranes could be improved by blending with organic/inorganic additives or by treating plasma and radiation induced grafting techniques. In this study, acrylic acid (AA) was applied to surface of the polyvinylidene fluoride (PVDF) membrane by chemical grafting method to obtain better membrane materials. Changes were investigated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and contact angle measurement techniques. The presence of the bands indicated acrylic groups and increase at cross section thickness of AA grafted sample after modification confirmed the progress of grafting. Coated skin layer onto membrane surface was seen at the SEM images. Water uptake capacities (WU%) of acrylic acid grafted membrane increased to 64% from 57% of unmodified PVDF relatively with increasing hydrophilicity understood by decreasing contact angles of AA modified samples. By using easy and low cost method, acrylic acid was effectively incorporated on to surface of the PVDF membrane. That is the convenient application to prepare functional structures which contain specific groups on surface of membrane via acrylic molecules in addition to obtain high performance filtration membranes.