Preparation and performance of novel thermally stable composite reverse osmosis membranes

Novel thermally stable aromatic polyamide(APA) composite reverse osmosis(RO) membranes were prepared from metaphenylene diamine and trimesoyl chloride on poly(phthalazione ether nitrile ketone)(PPENK) ultrafiltration membranes by interfacial polymerization.The effects of monomers concentration and reaction time on the performance of composite membranes were studied.Furthermore, the surface morphology and chemical structure of membranes were examined by scanning electronic microscopy and fourier transform infrared spectroscopy(FT-IR),respectively.Moreover,the thermal stability of RO membranes was also discussed.When the operation temperature increased from 20℃to 95℃,the salt rejection of membranes was kept about 97.9%,while the flux of membranes increased from 7.4 L/(m~2·h) to 31.4 L/(m~2·h);the flux increased first then reached a plateau and the salt rejection kept constant when RO membranes in boiling water were boiled to 3 h.In a word,APA-PPENK composite RO membranes show good thermal stability.