Enhanced permeability and antifouling properties of carboxylated polysulfone/quaternized polyimide blend ultrafiltration membrane

Abstract The intricate interplay between chemical composition and the incorporation of functional fillers plays a pivotal role in shaping the structural attributes and separation efficacy of mixed matrix ultrafiltration membranes. In this work, we report the utilization of a novel organic filler of hydrophilic modified polyimide particles (PI‐SO 3 ) for the first time in the preparation of mixed matrix ultrafiltration membranes. A series of ultrafiltration membranes were fabricated using polysulfone as the matrix material and PI‐SO 3 as the additive. The addition of PI‐SO 3 to the mixed matrix membrane effectively enhanced both water flux and antifouling ability. The ultrafiltration membrane with 0.2% particle content exhibited the highest pure water flux at 535.5 L h −1 m −2 , owing to the synergistic regulation of pore structures and surface hydrophilicity. The ultrafiltration membrane with 0.5% PI‐SO 3 particles demonstrated the highest flux recovery rate at 76.8%, attributed to the superior hydrophilicity displayed by the added particles within the ultrafiltration membrane. The increased particles content correlated with improved hydrophilicity on the membrane surface, resulting in enhanced antifouling performance. The hydrophilic modified particles effectively regulated pore structures, surface hydrophilicity, and surface charge, ultimately enhancing the performance of mixed matrix ultrafiltration membranes for wastewater purification. Therefore, the use of modified polyimide particles as fillers introduces an innovative method to economically enhance ultrafiltration membranes, providing a potential solution to mitigate the economic costs associated with trade‐off effects during the modification process.