The role of nanoparticles in the performance of nano-enabled composite membranes - A critical scientific perspective.

This review looks into the efforts made towards commercializing nano-enable flat sheet membranes as well as the challenges that need to be overcome. There is a question mark on the argument that the nano-pores of the fillers play a significant role in the performance of the membrane. Non porous nanomaterials have been reported to cause in increase in water flux, yet there are still articles that credit the nano-pores of the nanomaterials for improved membrane performance. There are two points that are important to highlight: (1) the nanoparticles, e.g. zeolites, are smaller in diameter compared to the thickness, (2) the loading rate of the filler phase is significantly small in relation to continuous phase. Therefore, it cannot be correct to assume that the nanomaterials provide continuous flow channels in the selective layer. There is no dispute here that the addition of NP enhances the performance of a membrane, but it is the perception that the nano-pores are the reason that we disagree with.