Synthesis of protein-fouling-resistance polyelectrolyte multilayered nanofiltration membranes through spin-assisted layer-by-layer assembly

Abstract

Membrane fouling is a persistent problem that deteriorate membrane performance, impose additional cost for membrane cleaning and even membrane replacement. The objective of this work is to synthesis membranes that show high fouling resistance and demonstrate high membrane performance. Thin film composite nanofiltration membranes were fabricated through spin-assisted layer-by-layer assembly by depositing alternate layers of poly(diallyl dimethyl ammonium chloride) (PDAC) and poly(sodium 4-styrenesulfonate) (PSS) on polyethersulfone membranes as substrates. The membrane consisting of 35 layers of PDAC/PSS prepared from polyelectrolyte solution containing 0.05 M NaCl showed a rejection rate of 94.58% for MgCl2 and a permeability of 3.32 L/m2·h·bar during tests performed using a cross-flow permeation cell, MgCl2 concentration of 600 ppm, pressure of 10 bar, and temperature of 33 °C. The performance of the membranes with respect to organic foulant using a solution containing 20 mg/L bovine serum albumin showed approximately 10% decrease in permeation flux from the initial level within the first 24 h of testing, with the subsequent changes being only marginal for the next 72 h of testing. These results suggest that this new fabrication method is suitable for producing polyelectrolyte multilayered NF membranes that exhibit relatively high fouling resistance and excellent membrane performance.