(159aq) All-Organic Thin Film Nanocomposite Membrane for Organic Solvent Nanofiltration

The high chemical stability and hydrophobicity of the fluoropolymers make them suitable for use in organic solvent nanofiltration (OSN). Along this line, here, we report on the synthesis of poly(divinylbenzene-co-perfluorodecyl acrylate) (poly(DVB-co-PFDA) nanoparticles (NPs), via radical polymerization, that were further integrated into the architecture of the thin film nanocomposite (TFN) membrane. Herein, the nanomaterial was incorporated into the PA layer via two different approaches. In the first approach, nanoparticles were dispersed in hexane and sprayed on the substrate, right after it was removed from amine-containing precursor solution. In the second approach, the NPs were dispersed in hexane phase, containing trimesoyl chloride (TMC) (TTFN). The performances of TFN OSN membranes were compared with the control thin film composite (TFC) membranes. The NPs concentration ranging from 7.5 mg to 12.5 mg were added to PA layer. The membrane prepared with spray processing of NPs demonstrated superhydrophobic properties, while those prepared by dispersing the NPs in hexane phase were only highly hydrophobic, with a contact angle of 125^o ±1.5^o. Furthermore, membranes prepared via spray coating process exhibited the highest toluene permeance of 1.7 L/m² h bar, approximately 5.6 times higher than the control TFC membrane (0.3 L/m² h bar) without compromising the dye rejection. We attributed the enhanced performance of the TFN membrane to the enhanced roughness and hydrophobicity of the active layer.