High-flux microfiltration filters based on electrospun polyvinylalcohol nanofibrous membranes

A novel class of high-flux microfiltration filters consisting of an electrospun nanofibrous membrane and a conventional non-woven microfibrous support is being presented. The nanofibrous non-woven layer was fabricated by electrospinning of polyvinylalcohol (PVA) directly onto the microfibrous support and then followed by chemical cross-linking with glutaraldehyde (GA) in acetone. By altering the processing parameters, such as the applied voltage and the distance between the spinneret and the collector, as well as the concentration of PVA solution, electrospun PVA membranes with an average fiber diameter of 100 ± 19 nm were obtained. Characterizations revealed that the mean pore size of the electrospun PVA membranes ranged from 0.30 μm to 0.21 μm with the electrospun PVA membrane thickness varying from 10 m to 100 μm. Due to the high porosity, microfiltration filters based on these electrospun membranes showed 3-7 times higher pure water flux than the Millipore GSWP 0.22 μm membrane. The nanofibrous PVA membranes with an average thickness of 20 μm could successfully reject more than 98% of the polycarboxylate microsphere particles with a diameter of 0.209 ± 0.011 μm, and still maintain 1.5-6 times higher permeate flux than that of the Millipore GSWP 0.22 μm membrane.