Fabrication of TFC nanofiltration membranes via co-solvent assisted interfacial polymerization for lactose recovery

Abstract

This work has focused on the development of thin film composite (TFC) nanofiltration membranes via co-solvent assisted interfacial polymerization (CAIP) procedure by a new co-solvent to increase the membrane permeability. The nano-porous polyamide layer was made on the sulfonated polyethersulfone (SPES) support as a result of polymerization reaction between 1,3-Phenylendiamine and trimesoyl chloride. The effect of two types of ketone co-solvent (propanone and butanone) on the physiochemical characteristics of polyamide layer was studied by FTIR spectra, SEM and AFM analysis. The performance of membranes was evaluated using NaCl solution and pre-treated whey by ultrafiltration (UF) for lactose recovery. According to the AFM and SEM images, the membranes prepared using CAIP method demonstrated to have thin film layer with larger average pore size and lower roughness. The flux of these membranes was higher compared to the membrane prepared without the contribution of ketone co-solvent. In spite of flux increment, the rejection of lactose and NaCl did not exhibit any remarkable loss. Among propanone and butanone co-solvent, adding propanone to the organic phase led to form thinner and smoother polyamide layer, which was as a result of the difference in solubility parameter. Keywords: Thin film composite membrane, Nanofiltration, Ketone co-solvent, Interfacial polymerization, Lactose separation