Development of Hydrophilic Polylactic Acid Hollow-Fiber Membranes for Water Remediation

Abstract

In past decades, membrane technology has been widely believed for water remediation and purification. However, the waste membranes, which is conventional nonbiodegradable polymeric materials, causes secondary pollution and hampers the application of membrane technology. As an industrialized biodegradable polymer, polylactic acid (PLA) is believed as an alternative to conventional polymeric membrane materials, while suffering from its intrinsic strong hydrophobic properties. Herein we provide a facile method to improve the hydrophilicity of PLA hollow-fiber membranes through tailoring the phase inversion process by introducing Tween-80 and polyvinylpyrrolidone K30 (PVP-K30) as coadditives. During the phase inversion process, Tween-80 enhances the dispersity of the PVP-K30 and promotes the shifts of the PVP-K30 toward the surface of the membrane through hydrogen bonding, tailoring the pore structure and the surface properties of the membranes. Consequently, the water permeance of the modified PLA membranes increases by 816.4% (151.2 L m–2 h–1 bar–1). Moreover, the membranes also demonstrate excellent antifouling performance with permeance recovery rate up to 86.8%, showing strong promise in substituting conventional polymer membranes for water remediation.