Water transport properties of boron nitride nanosheets incorporated thin film nanocomposite membrane for salt removal

Abstract

This work has focused on the fabrication of thin film composite (TFC) and thin film nanocomposite (TFN) membranes for reverse osmosis (RO) application. Raw boron nitride (BN) and chemically activated boron nitride (A-BN) were used as nanofillers in polysulfone support layer and trimesoyl chloride (TMC) to improve the membrane performance. Different concentrations of BN and A-BN (ranging from 0 to 1 wt %) were added to the polysulfone (PSf) microporous support and polyamide layer was formed on top of PSf support through interfacial polymerization of 1,3-Phenylendiamine and trimesoyl chloride. The fabricated TFN membranes were characterized in terms of membranes structure, contact angle, separation properties, as well as RO performance. According to AFM and SEM images, TFN membranes showed larger average pore size and higher surface roughness as compared with TFC membrane. Thus, TFN membrane showed higher pure water flux but lower NaCl rejection. The addition of BN led to increase in pore size of membrane without increase the selectivity of membrane. The addition of both BN and A-BN into polyamide layer does not aid to improve the properties of membrane. In conclusion, BN nanoparticles showed the potential to be used as nanofillers that aid in formation of larger pore size.