A thin film composite membrane prepared from monomers of vanillin and trimesoyl chloride for organic solvent nanofiltration

Abstract This paper describes the formation of a new polyarylester thin film vanillin composite membranes for organic solvent nanofiltration (OSN). Vanillin (VA), a naturally occurring monomer, was adopted to synthetize a hydrophobic OSN membrane via interfacial polymerization with trimesoyl chloride (TMC) on the ethylenediamine cross-linked poly(ether imide) substrate (C-PEI). The prepared membrane was proved by chemical characterizations such as ATR-FTIR, XPS etc., it is illustrated that the interfacial polymerization occurs among TMC and VA on the C-PEI support to generate the polyarylester layers with crosslinked polyimide structure, and the further contact angles measurements revealed that the hydrophobicity of the membranes increased with the VA loading. Besides, the study on the relationship between the membrane permeance and the membrane-solvent solubility parameter distance were performed by Hansen solubility parameter methods. The optimal NF-3VA membrane exhibited a higher chemical stability in THF and superior separation performance with the rejection of 93% for crystal violet (CV) and a THF permeance of 4.5 L m-2 h-1 bar-1, and the separation factor of CV and THF can reach 14 at the optimal condition. These results suggest a novel strategy to select potential monomers to develop advanced membranes applicable to organic solution separation for future sustainable usages.