High-flux microfiltration filters based on electrospun polyvinylalcohol nanofibrous membranes

A novel class of high-flux microfiltration filters consisting of an electrospun nanofibrous membrane anda conventional non-woven microfibrous support is being presented. The nanofibrous non-woven layerwasfabricated by electrospinning of polyvinylalcohol (PVA) directly onto the microfibrous support and thenfollowed by chemical cross-linking with glutaraldehyde (GA) in acetone. By altering the processingparameters, such as the applied voltage and the distance between the spinneret and the collector, as well asthe concentration of PVA solution, electrospun PVA membranes with an average fiber diameter of100 19 nm were obtained. Characterizations revealed that the mean pore size of the electrospun PVAmembranes ranged from 0.30 mm to 0.21 mmwith the electrospun PVA membrane thickness varying from10 m to 100 mm. Due to the high porosity, microfiltration filters based on these electrospun membranesshowed 3e7 times higher pure water flux than the Millipore GSWP 0.22 mm membrane. The nanofibrousPVA membranes with an average thickness of 20 mm could successfully reject more than 98% of the polycarboxylatemicrosphere particles with a diameter of 0.209 0.011 mm, and still maintain 1.5e6 timeshigher permeate flux than that of the Millipore GSWP 0.22 mm membrane.