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N-bromo-hydantoin and N-bromo-5,50 -dimethylhydantoin conjugated polystyrene beads were synthesized from chloromethyl polystyrene beads which differ in their particles size, crosslinking, nano-micro porosity, and tunnels size on the surface, in order to study the effect of these parameters on oxidative halogen release and resultant activity, for water purification applications. The synthesized beads were characterized using elemental analysis, FT-IR, solid state 13 C-NMR, and scanning electron microscope (SEM). The conjugation yield and kinetics in different solvents and bromine loading capacity were studied. The N-bromoamine polystyrene beads were tested for water decontamination according to NSF 231 protocol. The release of active bromine was analyzed by spectrophotometer using a DPD-1 kit and also studied the antimicrobial activity against Escherichia coli and MS2 phages. Bead's nano-micro characteristics were found critical for oxidative halogen release control: rate stabilization and modulation, extension and also influences antimicrobial activity. The synthesized beads exhibited extended and stable release of bromine, 6 and 4 log reduction for E. coli and MS2, respectively for 250 L of passing contaminated water. Thus, N-halamine hydantoins conjugated polystyrenes, chemically or kinetically release modified should have applications as disinfectants in water purification systems as well as medical field.

Silica particles functionalized with quaternary ammonium groups were prepared by interpenetrating polyethylenimine (PEI) into silica particles and crosslinking with diiodopentane, followed by octyliodide alkylation and methyliodide quaternarization (S-QA-PEI). The synthesized S-QA-PEI particles were identified with a slight particle size increase of 2-3 μm. Different ratios of PEI:silica particles were prepared and analyzed. While silica particles are negatively charged, À16.7 ± 5.11 mV, the prepared S-QA-PEI particles are positively charged, +50-60 mV. These particles were embedded in poly(ethylene vinyl acetate) and poly(ethylene methacrylic acid) coatings which exhibited strong antibacterial activity.

N-bromo-dimethylhydantoin polystyrene beads were synthesized and tested as antimicrobial agents for water microbial decontamination. Optimization of synthetic process was thoroughly investigated, including solvents used, ratio of reactants and reaction conditions, kilogram scale production, and detailed spectral analysis. The microbial inactivation efficiency was studied according to the NSF-231 Guide Standard and Protocol for Testing Microbiological Water Purifiers against Escherichia coli and MS2 phage. The tested resins maintained their activity for 550 L. Thus, N-bromo-dimethylhydantoin-polystyrene beads synthesized under optimized conditions at kilogram quantities have a potential use in water purification filters.

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