Synthesis of high-performance thin film composite (TFC) membranes by controlling the preparation conditions: Technical notes. (August 2019) - Kadhom, Mohammed
Abstract: Reverse osmosis (RO) is one of the most globally competitive technologies for desalination and water purification, in which thin film composite (TFC) membrane is the common form of membranes used. In this paper, we examined changes in membrane performance by studying the effects of 1) m -phenylenediamine (MPD) and trimesoyl chloride (TMC) exposure times; 2) different phase inversion methods to prepare polysulfone (PSU) support sheets; 3) the support sheet thickness, and 4) the fabricated membrane's drying temperature. Operational conditions of 300 psi, 25 °C, 2000 ppm NaCl, and sample run time of at least 8 h were applied. Optimal performance results were achieved when the interfacial polymerization time was short, and a vertical immersion during PSU layer preparation was applied. Increasing PSU sheet thickness increased the salt rejection but decreased the water flux, while rising the curing temperature led to an enhancement in salt rejection and water flux at short reaction times. Based on this study, a TFC membrane of NaCl rejection 98.8 ± 0.5% and water flux 76.1 ± 2.7 L/m 2 h was fabricated using 25 s MPD contacting time, 5 s TMC reaction time, and 110 °C drying temperature. This result is considered high among reported outcomes in the literature for simply prepared TFC membranes.