Properties of Hydrophilic Chitosan/Polysulfone Nanofibrous Filtration Membrane

Abstract

Electrospun nanofibrous membranes are useful water filtration materials due to their high interconnected porosity and tunable pore sizes, which cause very high permeability and selectivity. However, poor mechanical properties and easy fouling due to their extremely high surface area limit their applications. Therefore, it is desirable to enhance the mechanical properties and the hydrophilicity of such electrospun nanofibrous membranes. In this paper, electrospun polysulfone (PSF) nanofibrous membranes were treated with plasma. Crosslinked chitosan solution was then employed to pad the membranes. We studied the influence of the chitosan concentration and the volume of glutaraldehyde on the morphology, porosity structure, mechanical properties and hydrophilicity of electrospun polysulfone nanofibrous membranes. The results showed that the average pore size decreased from 4.5 μm to 2.68 μm, the breaking stress increased from 6.01±0.44 MPa to 9.25±0.45 MPa, and the water contact angle decreased from 130.8° to 0° in 30 s when chitosan was applied to the membranes. These changes occurred by padding due to the crosslinked chitosan solution. The results indicate that a significant improvement occurred in the mechanical properties; the highly hydrophobic PSF membrane was changed to a superhydrophilic one and the pore size was reduced. These results encouraged us to propose this material as a water filtration membrane with longer life span, lower fouling and higher rejection efficiency.