Chitosan nanofiltration membranes with gradient cross-linking and improved mechanical performance for the removal of divalent salts and heavy metal ions

Chitosan (CTS) and 1,3,5-triglycidyl isocyanurate (TGIC) were gradiently cross-linked on the polyethersulfone ultrafiltration membrane (PES) to prepare a new type of positively charged composite nanofiltration membrane. The influence of preparing conditions on the membrane performance, such as permeability, mechanical strength, membrane morphology, and nanostructures was systematically discussed. The rejection performance to MgCl2, Na2SO4,...