Preparation of microporous organic solvent nanofiltration (OSN) composite membrane from a novel tris-phenol monomer

As an emerging membrane separation technology, organic solvent nanofiltration (OSN) has shown great application potential in the field of pharmaceutical and chemical industries referring to organic media. Herein, we prepared a novel microporous thin-film composite (TFC) OSN membrane with superior perm-selective performances, which was fabricated by applying 4,4′,4″-trihydroxytriphenylmethane (Tris-Phenol) to react with trimesoyl chloride (TMC) by interfacial polymerization (IP) technique. The rigid, non-planar and multifunctional nature of Tris-Phenol endowed the polyarylate nanofilm with enhanced microporosity. Of note, the prepared composite membrane showed good selectivity to small organic solutes with molecular weight cut-off (MWCO) as low as ∼295 Da, meanwhile had medium methanol permeance up to 5.86 LMH/bar, by the help of surfactant dodecyl trimethyl ammonium chloridea (DTAC) during the IP reaction. The experiments showed that the Tris-Phenol membrane exhibited extraordinary long-term operation stability. In addition, the Tris-Phenol membrane could achieve separation of solutes with similar molecular weights but different charges. This research well illustrated the novel IP monomer design strategy to fabricate new TFC OSN membrane with high perm-selectivity.