Development of PVDF/SiO_۲ Mixed Matrix Membrane via Vapor-Induced Phase Separation for Membrane Fouling Control

Although mixed matrix membranes (MMMs) exhibit good fouling resistance, retaining sufficient inorganic additives during phase inversion remains a challenge. A large portion of the additive diffuses into the nonsolvent bath due to its affinity, leaving too little in the membrane matrix for optimal membrane performance. This research presents a cost-effective and facile concept for optimizing MMM development by restricting the diffusion rate of the additive to the nonsolvent through manipulation of the membrane formation mechanism. By exposing the cast film to ۹۰ % humid air, for ۲۰ seconds before the immersion into the nonsolvent bath (V-NIPS), the surface of the cast film slowly uptakes nonsolvent from the humid air resulting in the formation of an immobile thin layer that restricts the mobility of the additive to the nonsolvent during the cast film coagulation. Thereby, it transforms the membrane hydraulic output and the membrane fouling resistance during humic acid fouling filtration by approximately ۴۹۰ % and about ۶۱ %, respectively. By subjecting the cast film to ۲۰ seconds before coagulation (V۲۰), the resulting membrane recorded ۳۷.۰۲ ± ۱.۸  as water permeability, while the baseline membrane (V۰) reported just ۶.۲۸ ± ۰.۹  as water permeability. Moreover, the results of the surface characteristic analysis justify the improvement in the SiO۲ surface density in the V۲۰ by up to approximately ۱۸ % compared to the baseline V۰. The overall results of this research demonstrate the economic potential of the V-NIPS technique in improving the antifouling performance of mixed matrix membranes as well as its sustainable applications.

کلیدواژه ها:

Membrane Fouling ، mixed matrix membrane ، Silica (SiO۲) ، Vapor-Nonsolvent phase separation ، Humic acid wastewater filtration