(595g) Effects of MCM-41 Silica Nanoparticles on the Performance of Thin Film Nanocomposite Membranes for Reverse Osmosis

Reverse osmosis (RO) has been increasing applied for water desalination since the successful development of thin film composite membranes (TFC) by Cadotte three decades ago. In this work, a series of TFC membranes were prepared by reacting m-phenylenediamine (MPD) solution containing triethylamine/ camphorsulfonic acid salt (TEA/CSA salt) and calcium chloride with trimesoyl chloride (TMC) solution on a polysulfone (PSU) support sheet. The PSU support sheets were prepared by dissolving PSU in N,N-dimethylformamide (DMF) and then casting on a glass plate. In particular, isooctane with an intermediate boiling point was used for the first time as a solvent to dissolve TMC, which helped the membrane fabrication process. The TMC/isooctane solution contained an increasing amount of MCM-41 spherical silica nanoparticles (0.01%, 0.015%, 0.02%, 0.025%, 0.03% and 0.04%) during the fabrication of the thin-film nanocomposite. The performance testing demonstrated that the water flux was increased for all membranes with the silica nanoparticles though the salt rejection was often decreased slightly. With the addition of 0.015% of the silica nanoparticles, the water flux was increased from 44 to 61 L/m2hr while the rejection of NaCl was maintained essentially the same at 95%.