Measuring the Volume-Averaged Charge Density of Active Layers of Thin-Film Composite and Nanocomposite Membranes Using a Quartz Crystal Microbalance

摘要

Membrane-based separation processes such as reverse osmosis (RO) and nanofiltration (NF) typically make use of polyamide-based thin film composite (TFC) membranes as the separation barrier. TFC membranes are commonly comprised of three layers: an ultrathin polyamide top layer (～20-100 nm), an intermediate porous polysulfone layer (～30 mm) and a non-woven polyester backing (～200 mm). A recent development in membrane technology, zeolite thin-film nanocomposite (TFN) membranes, have the same structure as TFC membranes with the difference that the active layer of TFNs have zeolite nanoparticles dispersed throughout the active layer.