Immobilization of cyclic N-halamine on polystyrene-functionalized silica nanoparticles: Synthesis, characterization, and biocidal activity

Antimicrobial composites with a well-defined core-shell nanostructure were prepared through immobilization of N-halamine on polystyrene-functionalized silica nanoparticles. Evidence for immobilization of N-halamine onto polystyrene-modified silica has been inferred from different techniques like transmission electron microscopy (TEM), dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), zeta potential analyses, and Fourier transform infrared (FTIR). Experimental results showed that structures and morphologies of the as-prepared hybrid nanoparticles could be well controlled. Resultant nanosized particles displayed 2-8 times higher biocidal activity against S. aureus and E. coil than the bulk counterparts, and tests indicated that these powerful and stable nanosized antimicrobials had higher biocidal efficacy against S. aureus than E. coli. The biocidal behavior makes these composite nanoparticles an ideal candidate for various important applications such as in disinfection of hygienic areas, water purification, and food packaging.