Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Bio-inspired tannic acid-functionalized carbon nanotubes modify polysulfone ultrafiltration membranes via NIPS. The optimal 7 wt% membrane achieves 450 L m−2 h−1 water flux, 97% BSA rejection, and 75% flux recovery rate, offering a green strategy for high-performance anti-fouling separation membranes.

ABSTRACT
The inherent hydrophobicity of polysulfone (PSf) membranes frequently leads to membrane fouling issues. To address this limitation, a novel composite membrane was developed by incorporating hydrophilic tannic acid-modified carbon nanotubes (TCNT). The TCNT nanomaterial was synthesized by functionalizing carbon nanotubes (CNTs)─known for their exceptional organic compound adsorption capacity─with tannic acid (TA), which exhibits mussel-inspired adhesion properties for surface modification. The TCNT/PSf composite membranes were fabricated via non-solvent induced phase separation (NIPS). Characterization results demonstrated that increasing TCNT content enhanced membrane porosity, enlarged finger-like pore structures, and improved surface hydrophilicity (reduced contact angle). The optimal membrane with 7 wt% TCNT loading achieved outstanding performance: 97% bovine serum albumin (BSA) rejection and 450 L m−2 h−1 pure water flux (50% higher than the pristine PSf membrane's 300 L m−2 h−1). Moreover, the total fouling ratio (Rt) significantly decreased from 84% to 53%, confirming the substantially improved antifouling properties of the TCNT-modified PSf membranes. The biomimetic functionalization strategy of TA-CNTs provides a new idea for the development of next-generation anti-pollution membrane materials, and its green modification method is in line with the concept of sustainable development.