Development of Nanocomposite Polysulfone- Nanoclay Membrane with Enhanced Hydrophilicity

Abstract

This research involved the development of membranes with local raw materials to suit water and wastewater treatment applications. Indigenous montmorillonite clay was surface modified with dialkyldimethyl ammonium chloride to be used as functional additive in polymeric membranes. Polysulfone (PSf) pellets were dissolved in N-methyl-pyrrolidone (NMP) and organomodified-montmorillonite (OMMT) or nanoclay was incorporated at varying concentrations up to 1.00%. Casting solutions were vacuum-mixed and degassed using a planetary mixer then casted using MEMCAST™ to produce flat sheet membranes. Characterizations include X-Ray Diffractometry, Atomic Force Microscopy, Scanning Electron Microscopy, and contact angle measurement. The exfoliation of OMMT platelet structures within the PSf matrix at 1.00% loading showed improved surface roughness and more porous morphology. Improved surface roughness was observed with an increasing value as a function of increasing OMMT concentration. Meanwhile, the morphology of the nanocomposite membranes showed three distinct layers: dense skin layer, porous finger-like layer, and sponge-like structured layer. Moreover, the contact angle of the membranes decreased by 13.7% with 1.00% addition. This enhancement in hydrophilicity could affect properties like permeate flux and membrane fouling, which could play an important role in the functional performance of synthesized membranes with nanoclay additives. One-way ANOVA revealed that the change in OMMT concentration has significant effect on the surface roughness and contact angles of the membranes at 95% confidence level.