Functionalized Chitosan-Modified PVDF-co-HFP Polymer Inclusion Membrane for Enhanced Au(III) Extraction

Abstract

Gold recovery from aqueous solutions requires environmentally sustainable alternatives to conventional cyanide-based extraction processes. This study aimed to develop the polymer inclusion membrane (PIM) by incorporating functionalized chitosan into a poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) membrane to enhance the transport and extraction efficiency of Au(III) The membrane consisted of PVDF-co-HFP as the base polymer, Aliquat-336 as the carrier, and dioctyl phthalate (DOP) as the plasticizer, while functionalized chitosan was incorporated at concentrations ranging from 0.5 to 2.5 wt.%. The fabricated membranes were prepared using the solvent-casting techniques and characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle, and ion exchange capacity (IEC). The membrane containing 2.0 wt.% functionalized chitosan (M5) exhibited the highest Au(III) extraction efficiency of 98.19%.The improved extraction performance was attributed to enhanced membrane hydrophilicity, increased ion exchange capacity, and more efficient carrier-mediated transport. These findings demonstrate that the developed PIM system is a promising and sustainable membrane-based technology for high-efficiency gold recovery.