Piezoelectric membranes for separation processes : operating conditions and filtration performance

Filtration experiments using piezoelectric polyvinylidene fluoride (PVDF) microfiltration membranes showed that the out of plane vibration of these membranes increased flux and delayed fouling. The relative anti-fouling effect of the piezoelectrically induced vibration was enhanced by increasing the crossflow velocity, decreasing the operating pressure and applying greater AC signals to the membrane. The frequency of the signal was also found to affect the anti-fouling performance of the piezoelectric membranes. However, this was related to the factors associated with the frequency-dependent electrode effects rather than the piezoelectric response of the membranes themselves or its effect on filtration processes.