Antimicrobial superhydrophilic nanofibers: N-halamine-functionalized SiO2 membranes with dual-mode oil-water separation and bacterial killing

The integration of superwettability and antibacterial functionality into inorganic nanofibrous membranes presents a promising strategy to address the dual challenges of oil-water separation and microbial contamination. In this study, we engineered an N-halamine-functionalized SiO 2 nanofibrous membrane (APTS-SiO 2 NFMs-Cl) through a synergistic electrospinning, sol-gel amination, and chlorination process, leveraging the covalent grafting of APTS and subsequent transformation of -N-H to N-Cl active sites. The APTS-SiO 2 NFMs-Cl’s superhydrophilicity/underwater superoleophobicity, governed by its high surface energy and hierarchical nanofibrous architecture, enables efficient separation of oil-water emulsions while resisting fouling through an anti-adhesion mechanism. Crucially, the N-halamine moieties endow APTS-SiO 2 NFMs-Cl with rapid, contact-driven bactericidal activity, achieving 99.9 % inactivation of E. coli and S. aureus within 20 min via oxidative chlorine release. In addition, the regeneration ability of APTS-SiO 2 NFMs-Cl was given by the mutual transformation between N-H and N-Cl bonds. The continuous antibacterial performance (>95 % efficiency) of APTS-SiO 2 NFMs-Cl after 20 chlorination-regeneration cycles showed that this was attributed to the dynamic reversibility of N-halamine chemistry. Beyond environmental applications, APTS-SiO 2 NFMs-Cl shown remarkable biocompatibility and hemocompatibility, suggesting strong potential for use in medical protective materials requiring simultaneous barrier and antimicrobial functions. Overall, this study provided a new strategy for designing robust, multifunctional inorganic nanofiber membranes that bridge environmental remediation and biomedical protection.