Nanofibrous membrane of wool keratose/silk fibroin blend for heavy metal ion adsorption

In this study, SF and WK/SF blend nanofibrous membranes were prepared by electrospinning and their performances were evaluated as a heavy metal ion adsorbent. The electrospun nanofibrous membranes were comprised of randomly oriented ultra-fine fibers of 200-400 nm diameters. As a result of pressure-flux test, the membranes exhibited similar flux to ordinary microfiltration membrane. Metal ion adsorption test was performed with Cu²⁺ as a model heavy metal ion in a stock solution. Due to large surface area and high porosity of electrospun nanofibrous structure, the nanofibrous membranes exhibited high metal ion capacities compared with common fibrous filters (wool sliver and filter paper). Especially, the WK/SF blend nanofibrous membrane had an exceptional performance for the adsorption of metal ions. Furthermore, its adsorption capacity has been maintained after several recycling process (desorption and re-adsorption) which is very advantageous as an affinity membrane. The electrospun WK/SF nanofibrous membrane is very suitable for removing and recovering heavy metal ions in water.