Experimental investigation of fibroin content in polymethyl methacrylate‐based membranes for removal of heavy metals in aqueous solutions

Abstract Membrane technology has recently been given extensive consideration for the treatment of effluent to remove suspended solids, organic compounds and inorganic contaminants such as heavy metals. The aim of this study was to prepare, characterize, and test membranes made of silk fibroin (SF) and polymethyl methacrylate (PMMA) blend with different wt% ratios (5%, 10%, and 15%), respectively. The membranes were prepared by phase inversion scheme using water as non‐solvent. Fourier transform infrared spectroscopy (FTIR) was performed to find chemical interactions between polymer matrix and fibroin. The mechanical property of synthesized membranes was also carried out. The surface roughness, and finger‐like pore geometry developed by impregnation of fibroin filler in membrane matrix were depicted by atomic force microscopy (AFM) and scanning electron microscope (SEM), respectively. Surface porosity improved from 4.5% ± 1.9% to 30.0% ± 2.8%, water contact angle reduced from 68° ± 3.0° to 38° ± 1.2°, and highest pure water permeation value (31 L m −2 h −1 ) was obtained with the addition of fibroin loading. The membrane showed a greater affinity for Cr(VI) in comparison with Pb(II). The highest % rejection was evaluated to be 83% and 56% for Cr(VI), and Pb(II) by utilizing 1.70 wt% fibroin filler in membrane composition, respectively.