Effect of Organoclay Content on the Physicochemical and Separation Properties of PVDF/Clay Nanocomposite Membranes

Polyvinylidene fluoride (PVDF)/clay nanocomposite membranes with different nanoclay loadings (0–5 wt%) were prepared via the non-solvent induced phase inversion method. Effects of organo-montmorillonite (OMMT) content on the morphology and performance were systematically investigated. Results showed that OMMT was uniformly exfoliated and dispersed in the PVDF matrix, while the nanocomposite membranes consistently maintained the β-crystalline phase of PVDF. The incorporation of nano-clay significantly enhanced membrane hydrophilicity, porosity, pure water flux, and protein rejection performance: when clay content increased to 5 wt%, the pure water flux improved from 89.8 L·m−2·h−1 to 216.3 L·m−2·h−1, with rejection rates of 98.6% for bovine serum albumin (BSA) and 95.1% for pepsin. Mechanical tests showed that 3 wt% was the optimal clay loading, at which the storage modulus of the membrane increased by 59.8% compared to neat PVDF membranes. Antifouling experiments revealed that the nanocomposite membranes exhibited significantly lower irreversible fouling resistance, substantially improved hydraulic cleaning flux recovery rates, and markedly enhanced antifouling properties. Furthermore, long-term stability, economic analysis, and environmental safety assessments confirmed the practical application potential of these nanocomposite membranes in water treatment. These findings provide theoretical support and technical references for the preparation and application of high-performance PVDF ultrafiltration membranes.