tailieunhanh - Separation performance of poly (vinyl alcohol) based nanofiltration membranes crosslinked by malic acid for salt solutions

In this study, poly(vinyl alcohol) (PVA) based nanofiltration (NF) membranes were prepared by coating a thin PVA film on polysulfone ultrafiltration support substrates. The PVA film was cross-linked using malic acid in the presence of HCl as a catalyst. The impacts of crosslinker content and PVA molecular weight on physicochemical properties and separation performance of the prepared membranes were investigated. | SCIENCE & TECHNOLOGY DEVELOPMENT, Vol 19, 2016 Separation performance of poly(vinyl alcohol) based nanofiltration membranes crosslinked by malic acid for salt solutions Tran Le Hai Van Thi My Linh Vuu Ngoc Duy Minh Mai Thanh Phong* Ho Chi Minh city University of Technology, VNU-HCM (Manuscript Received on April 21st, 2016, Manuscript Revised May 17th, 2016) ABSTRACT In this study, poly(vinyl alcohol) (PVA) (MgSO4) as well as sodium chloride (NaCl) based nanofiltration (NF) membranes were prepared by coating a thin PVA film on solutions using a custom fabricated 4-cell crossflow desalination system. On increasing the polysulfone ultrafiltration support substrates. The PVA film was cross-linked using malic acid malic acid content, the extent of crosslinking degree increased and disrupted the crystallinity in the presence of HCl as a catalyst. The impacts of crosslinker content and PVA molecular weight of the PVA film. The salt rejection of the prepared membranes was found to increase and then on physicochemical properties and separation decrease through the maximum point of malic performance of the prepared membranes were investigated. The obtained membranes were acid content for 20 wt%, while the water permeability showed the opposite trend. characterized using FTIR spectra, swelling degree, and sessile drop contact angles, Moreover, the results revealed that the prepared membrane with higher molecular weight respectively. Then, the separation performance of the NF membrane was systematically exhibited lower water permeability but better salt rejection. evaluated for pure water; magnesium sulfate Key words: nanofiltration, membrane, poly (vinyl alcohol), brackish water, desalination. 1. INTRODUCTION Nanofiltration (NF) membranes, a particular Accordingly, they are favorable to the separation category of driven-pressure membranes, provide the separation properties of reverse osmosis (RO) of hardness metal ions, toxic and .