Modified forward osmosis membranes by two amino-functionalized ZnO nanoparticles: A comparative study

Abstract

In the current research, the self-synthesized amino functionalized nanoparticles (Zinc oxide nanoparticles modified by1,3-phenylendiamine (M.ZnO) and Triethylenetetramine (T.ZnO)) were synthesized as a new modifier to create thin film nanocomposite membranes for forward osmosis processes (FOP). Prior to efficiency evaluation, the pristine and amino functionalized membranes were characterized utilizing FTIR, FESEM, AFM and contact angle. The FTIR outcomes demonstrated that amine compounds has been successfully attached on the ZnO NPs surface. Comparing to the pristine TFC membrane, the TFN-M.ZnO0.3 membrane (TFC membrane incorporated with 0.3%w M.ZnO) exhibited insignificant increment in water flux and also insignificant decrement in rejection while the TFN-T.ZnO0.3 membrane (TFC membrane incorporated with 0.3%w T.ZnO) exhibited remarkable increment in water flux and insignificant decrement in rejection. Also for Caspian seawater desalination, TFN-M.ZnO0.3 and TFN-T.ZnO0.3 demonstrated water flux of 12.99, and 19.87 L/m2 h respectively. The insignificant increment in flux of TFN-M.ZnO0.3 membrane is associated to the rigid and compact structure of this membrane because of present of MPD monomer in M-ZnO NPs and the remarkably increment in flux of TFN-T.ZnO membrane is associated to the pendant group of TETA that create large free volume in TFN-T.ZnO0.3 membrane. The excellent separation efficiency of the TFN-T.ZnO0.3 membrane in FOP is closely related to the its higher pore sizes, hydrophilicity and porosity as well as low S parameter in comparison to TFN-M.ZnO and bare membranes. Our research provides worth guidelines for producing of amino functionalized TFN membranes for FOP.