Document Type : Original research
Faculty of Chemical Engineering, Sahand University of Technology, Tabriz, Iran
Membrane Technology Research Center, Sahand University of Technology, Tabriz, Iran
An essential characteristic for high performance inherently hydrophobic membranes such as microporous high density polyethylene (HDPE) membranes is to have a hydrophilic surface. In this project, wet chemical functionalization as a facile and effective method was developed to give a hydrophilic property to HDPE membranes using polar functional groups. KClO3, K2Cr2O7 and KMnO4 were selected as oxidizing agents. The optimum concentrations and treatment time intervals were determined for each oxidizing agent. Water contact angle and pure water flux measurements were conducted to evaluate the surface hydrophilicity and membrane performance, respectively. The results showed that among different oxidizing agents, 1wt% K2Cr2O7 solution with 60 min immersion time had the highest impact on the pure water flux. The percentage of re-construction phenomenon was about 4.70%, 21.94% and 32.6% for the HDPE membranes treated by KClO3, K2Cr2O7 and KMnO4, respectively. In addition, the attenuated total reflectance spectra-Fourier transform infrared spectroscopy (ATR-FTIR) results confirmed the presence of hydroxyl groups (O–H peak appeared at 3418.78 cm−1) in the membrane modified by KClO3. Bovine serum albumin (BSA) filtration experiments revealed that the total fouling ratio (TFR) and irreversible fouling ratio (IFR) decreased from 88.10% and 42.60% for pristine membrane to 65%, 68% and 72%
and 26.60%, 29.30% and 35% for the modified membranes treated by KClO3, K2Cr2O7 and KMnO4, respectively. The results indicated that incorporation of hydrophilic functional groups on the surface of HDPE membranes improved the fouling resistance behavior.