A Novel Nanofiltration Membrane Prepared with PAMAM and Graphene oxide for Desalination

Nanofiltration is increasingly gaining attention in many separation and treatment processes such as water softening, color removal and separation of medicines. Nanofiltration membranes are often negatively charged, displaying separation characteristics in the intermediate range between reverse osmosis and ultrafiltration. In this research, a novel nanofiltration membrane prepared with poly(amidoamine) (PAMAM) dendrimer and graphene oxide (GO) on amidoximated acrylic ultrafiltration membrane was investigated. Scanning Electron Microscopy (SEM) and contact angle of the water were employed to characterize the chemical and physical changes of resulting membranes. The flux and rejection of resulting membranes increased with increasing generation numbers of PAMAM for NaCl concentration. The salts rejections order of resulting membrane is CaCl2>MgSO4>NaCl>Na2SO4, which shows that resulting membranes were all positively charged NF membrane. The PAMAM/GO NF membrane is especially suitable for separating cationic solutes from others. This kind of membrane is also particularly suitable for treating acidic feed. The studied membrane possesses maximum operating pressure lower than 4 bar and excellent stability during continuous filtration at 27±2°C.