Covalent Crosslinked Assembly of Tubular Ceramic-based Multilayer Nanofiltration Membranes for Dye Desalination

摘要

A tubular ceramic-based multilayer composite nanofiltration membrane has been developed for dye desalination. Poly(a-crylic acid)(PAA)/poly(vinyl alcohol)(PVA)lglutaraldehyde(GA) was dynamically assembled on to the inner surfaces of tubular ceramic microporous substrates which had been pretreated using dynasylan ameo silane coupling agents. Subsequently, the composite membranes were thermally crosslinked to form covalent ester bonds. Experimental results proved that the composite membrane had good nanofiltration performance for dye desalination. The (GA/PVA/PAA)3/ceramic multilayer membrane shows over 96% retention of Congo red and less than 3% NaCl retention using a permeate flux of about 25 Ll(m~2·h). An investigation of membrane performance as a function of operating conditions suggested that the covalent crosslinking multilayer membrane possessed much higher stability compared to other, electrostatically assembled, multilayer membranes.