Nanoclays-Incorporated Thin-Film Nanocomposite Membranes for Reverse Osmosis Desalination

A series of thin-film nanocomposite (TFN) membranes with incorporation of Laponite nanoclays (NC-LAP) is prepared and demonstrated for brackish water and seawater desalination. It is the first attempt to use poly(ethylene glycol) 200 (PEG200) assisted Laponite as nanofillers to improve the performance of TFN membranes for reverse osmosis (RO) seawater desalination. The influence of NC-LAP loading and PEG200 as the dispersant on membrane properties is investigated. An increase in NC-LAP loading results in an increase in water permeability without sacrificing the salt rejection. At the loading of 0.3 wt%, the TFN membrane shows a water permeability of 2.7 L m(-2) h(-1) bar(-1) (LMH bar(-1)) and a salt rejection of 98.18% for brackish water desalination at 20 bar and 25 +/- 1 degrees C. This water permeability is 53% higher than the conventional thin-film composite (TFC) membrane. A steady water flux above 35 LMH is obtained when using seawater as the feed at 50 bar and 25 +/- 1 degrees C. The existence of PEG200 to effectively disperse NC-LAP nanoparticles is essential to fabricate the NC-LAP incorporated TFN membranes for brackish water and seawater desalination.