Evaluation of thin-film nanocomposite RO membranes using TiO2 nanotubes and TiO2 nanoparticles: a comparative study

AbstractThin-film nanocomposite (TFN) reverse osmosis (RO) membranes have gained attention due to their enhanced membrane performances in permeate flux and salt rejection. The structural shape of nanocomposites, such as particles and nanotubes, has been thought to have critical roles in improving their performances. However, the effects of the structural properties on membrane performance have yet to be verified. Herein, we reported the structural effects of nanocomposites on the performance of TFN RO membranes fabricated with TiO2 nanotubes (TNT) and TiO2 nanoparticles (TNP). The TFN RO membranes containing TNT or TNP exhibited similar high hydrophilicities and enhanced water permeability compared with a conventional RO membrane. In terms of membrane performance, the TNT TFN RO membranes had better water permeability than the TNP TFN RO membranes. Compared with non-porous TNP, 80-nm diameter nanochannels of TNT provided additional enhanced water permeability by serving as water transport passageways.