Homologous sulfonated PPS fibers reinforced PPS membrane for drug purification under harsh environments

Ineffective impurities in traditional Chinese medicine extracts can cause numerous issues, making the development of efficient and environmentally friendly purification technologies imperative. An ideal separation membrane must combine high selectivity, high permeability, and reliability under harsh environments. This study proposes a "homologous reinforcement" strategy, specifically, polyphenylene sulfide (PPS) fibers treated with sulfonation were employed as multifunctional reinforcement to fabricate the fibers reinforced PPS membrane via thermally induced phase separation (TIPS). The sulfonated PPS (SPPS) fibers exhibit the perfect interfacial compatibility with PPS matrix, significantly enhancing the mechanical strength as reinforcing skeletons while serving as effective nucleation sites during phase separation, which optimizes the composite membrane crystalline morphology and pore structure. Additionally, the tensile strength of the optimal composite membrane is enhanced by over three times compared to pure PPS membrane. In terms of separation performance, this prepared membrane achieves an effective balance between retaining five typical active components of traditional Chinese medicine and removing impurities. Furthermore, the introduction of SPPS fiber endowed the membrane with persistent hydrophilicity and negative charge, conferring the excellent anti-fouling properties and high flux recovery. More importantly, this SPPS modified composite membrane maintained outstanding structural integrity and separation stability under harsh environments such as harsh pH and organic solvents, ensuring reliable long-term operation.