Thin Film Nanofibrous Composite Electrospun Membrane for Separation of Salts

Abstract

Nanofibers have been commercially used as air filters but their use in liquid filtration is still considered to be at its infancy. In particular, there hasn?t been extensive research of electrospun nanofibrous membrane (ENM) in nanofiltration application. Hence the motivation of this thesis was to explore their use as nanofilters. The main objective of this thesis was to investigate how polymeric material, surface architecture and subsequently pore-size of ENMs influences its separation performance in nanofiltration. Interfacial polymerization (IP) was successfully carried out on the surface of ENM despite it having `large? pore size. The type of ENM polymer used had a major influence in the flux and rejection of salt ions. It is hypothesized that fiber size will play an important role in the separation efficiency of salt solution. A decrease in fiber size resulted in an increase in salt rejection but unfortunately a decrease in flux. However a decrease in thickness of the ENM layer together with fiber size led to an increased flux and high salt rejection. The capability of altering the fiber size and thickness of the electrospun layer so as to manipulate the rejection and flux as desired is highly advantageous for water treatment applications. This study shed new insight on the role of electrospun material as a liquid filtration membrane.