Effect of amine functionalization of SBA-15 used as filler on the morphology and permeation properties of polyethersulfone-doped ultrafiltration membranes

New polyethersulfone (PES) ultrafiltration hybrid membranes were prepared by doping with different amine-functionalized mesostructured silica (SBA-15) particles added at low weight concentration (0.6% in the synthesis medium). 3-(aminopropyl) trimethoxysilane, N-(3-trimethoxysilylpropyl)ethylenediamine, and N-(3-trimethoxysilylpropyl)diethylenetriamine were used as amine precursors of the fillers obtained by co-condensation and denoted as SBA-15/Monoamine, SBA-15/Diamine, and SBA-15/Triamine, respectively. SBA-15 material functionalized with polyethylenimine was synthetized by hyperbranching polymerization with aziridine. Physicochemical characterization of fillers was achieved by nitrogen sorption, X-ray diffraction, TEM, dynamic light scattering, and elemental analysis. Membrane morphology was assessed in terms of overall porosity by water uptake and surface pore size distribution from FEG-SEM. Hydrophilicity of the membranes was determined by measuring water contact angle. Significant increase of porosity and hydrophilicity was found in all doped membranes, which exhibited substantial improve in water flux in comparison with neat PES membrane. Filtration experiments conducted with BSA protein aqueous solutions (1 g L−1) revealed that antifouling ability of doped membranes was gradually enhanced with amine functionalization, especially against reversible fouling. PES/SBA-15/Triamine appeared as the best specimen in both water flux and antifouling behavior with excellent long time permeation performance in repeated cleaning/filtration cycles.