Chemical Modification of Polyvinylidene Fluoride (PVDF) Membrane and Applications on Milk Purification

Based on the chemical modification, the polyvinylidene fluoride (PVDF) membranes have been treated in KOH/KMnO4 solution to introduce active groups such as -OH. Then glycerin solution has been used to improve the chemical durability of the membrane surface. The parameters, involved reagents concentration, temperature and reaction time etc, have been changed to define the optimal reaction conditions. The result shows that the surface contact angles of modified membrane decreased significantly, and the membrane hydrophilicity improved. The comparison of those PVDF membranes before and after modification has been studied by separately applied them to practically casein separation test. It has been found that the surface of membrane after modification showed better anti protein adsorption capability by measuring the flux decline.