(42u) Filling of MCM-41 Silica Nanoparticles in Thin Film Nanocomposite Membranes to Purify Brackish Water

Reverse osmosis (RO) is a widely applied process for saline water purification.  Thin film composite membranes (TMC) are the most common type of membranes for this purpose. In this work, a group of TFC membranes were prepared by the in situ interfacial polymerization (IP) reaction of m-phenylenediamine (MPD) solution containing triethylamine/ camphorsulfonic acid salt (TEA/CSA salt) and calcium chloride with trimesoyl chloride (TMC) dissolved in isooctane.  The prepared membranes were fabricated on polysulfone (PSU) support sheets. The PSU support sheets were prepared by dissolving PSU in N,N-dimethylformamide (DMF) and then casting them on a glass plate.  The MCM-41 silica nanoparticles were mixed in both MPD and TMC solutions in an increasing amount (0.01%, 0.015%, 0.02%, 0.025%, 0.03% and 0.04%) during the synthesis 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 decreased slightly. It was noted that the addition of silica nanoparticles to MPD solution leading to slightly better and more stable results than adding them to TMC solution. With the addition of 0.02% silica nanoparticles to MPD solution, the water flux was increased from 44 to 64.1 L/m²hr while the rejection of NaCl maintained essentially the same at 95%.