Thin film composite solvent resistant nanofiltration membrane via interfacial polymerization on an engineered polyethylene membrane support coated with polydopamine

In this work, a thin film composite (TFC) membrane possessing outstanding properties for solvent resistant nanofiltration (SRNF) membrane application was fabricated. For this purpose, high density polyethylene (HDPE)-polystyrene (PS)-styrene-ethylene-butylene-styrene (SEBS) blends were fabricated in the first step by using an internal mixer machine and hot press technique, respectively. Then, the fabrication of a novel HDPE support was conducted by etching the PS phase out of the as-prepared HDPE-PS-SEBS blends through solvent extraction method (Etched HDPE). In the next step, the prepared Etched HDPE membrane support was dipped in a dopamine solution, by which auto-oxidization and self-polymerization of dopamine monomers onto the Etched HDPE membrane supports surface was done, leading to the formation of an ultrathin polydopamine (PDA) layer with a strong chemical binding force. By the formation of the polydopamine layer, hydrophilic functional groups were introduced onto the HDPE membranes surface, causing the attraction of m-phenylenediamine (MPD) monomers onto the membrane surface and the formation of a uniform ultrathin PA top layer. Finally, the TFC layer was formed on the as-prepared membrane supports via m-phenylenediamine and trimesoyl chloride (TMC). The performance of the prepared TFC-PE@PDA membrane was investigated for rejection of different dyes including Reactive Red, Direct Yellow, Methyl Blue, Rhodamine B, Crystal Violet and Methyl Orange in SRNF applications, based on which outstanding separation performance and good methanol flux were obtained. Furthermore, it is noteworthy that an outstanding solvent resistance (being dipped in Dimethylformamide at ۷۰°C for ۹۰ days) was also shown by the prepared TFC-PE@PDA membrane

کلیدواژه ها:

TFC membrane ، Binary blends ، HDPE support ، Polydopamine interlayer ، Solvent resistant nanofiltration (SRNF) membranes