A novel and facile semi-IPN system in fabrication of solvent resistant nano-filtration membranes for effective separation of dye contamination in water and organic solvents

Abstract

Numerous studies have been conducted to design and develop solvent-resistant nano-filtration membranes. In this research, an Interpenetrating Polymer Network (IPN) system was used to obtain solvent-resistant membranes. For this purpose, hydroxyl-terminated polybutadiene (HTPB) and multifunctional isocyanate (MFI) were incorporated as additives into the polyphenylsulfone membrane matrix and the achieved semi-IPN structure caused dimensional stability and solvent resistance in membranes. The structure and morphology of the membranes were investigated using Attenuated Total Reflection-Fourier transform Infra-red (ATR-FTIR), Field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis (EDAX), elemental mapping, and atomic force microscopy (AFM). The thermal properties of the membranes were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) and the mechanical properties were measured and the increase in tensile strength in compare of pure membrane was proved. The membranes showed excellent stability in acetone, n-heptane and dimethylformamide solvents. The performance of the membranes was evaluated by the pure water flux (PWF), contact angle, swelling degree, porosity assessment and dye rejection tests and the result showed that the PWF decreased with increasing HTPB percentage up to 40 wt% while their efficiency in removing methylene blue and methyl orange dyes was improved significantly due to reduced membrane pore size. The fabricated membranes were more resistant to fouling because of their hydrophilic nature.