Combinatory electrospray and electrospinning to produce multi-layered membrane with enhanced mechanical property

Abstract

Electrospun nanofibrous mats (ENM) have been extensively used for removal of suspended particles, cells and bacteria in membrane filtration because of its high porosity and permeability. However, microfiltration process is driven by a certain transmembrane pressure, and the filtration performance of traditional ENM are thereby hindered by its limited mechanical property. In this study, we propose a new strategy that sandwich the ENM between two layers of electrospray-deposited microparticles to enhance the mechanical properties of ENM membrane. Through a suitable thermal treatment, the microparticles stick with each other forming firm networks, while the ENM is rarely influenced. The mechanical tests show that the tensile strength and elastic modulus of the sandwich-structure composite membrane are 5 times and 7 times higher than those of the fibrous membrane, respectively. Meanwhile, the filtration tests show that the rejection rate of the composite membrane is also higher than the fibrous membrane. Our study implies the composite membrane fabricated by layer-by-layer deposition via electrospray and electrospinning has a great potential in microfiltration applications.