Armor polyamide reverse osmosis membrane with POSS 'armors' through two-step interfacial polymerization for high anti-chlorine and anti-bacteria performance

Improvement of anti-chlorine and anti-bacterial properties of membranes has been a major challenge in desalinating process. In this paper, zero-dimension cage-like structure polyhedral oligomeric silsesquioxane (POSS) was in situ armored on the surface of polyamide (PA) membrane and acted as 'armors' to prevent active chlorine corrosion and bacterial fouling. PA/POSS hybrid membranes could be easily achieved through a simple two-step interfacial polymerization. Anti-chlorine and anti-bacterial properties of PA/POSS hybrid membranes significantly improved during desalination by tuning the content of POSS 'armors'. Salt rejection reached approximately 98% after immersing PA/POSS hybrid membranes in the active chlorine solution for 24 h, which showed excellent anti-chlorine property. In addition, the anti-bacterial property of PA reverse osmosis (RO) membranes extremely enhanced after armoring with POSS nanoparticles. This finding demonstrated that the structure and chemical inert nature of POSS enabled PA/POSS membranes to block active chlorine and bacteria. PA/POSS membranes provided a promising approach to improve membrane desalination.