Polymeric Antimicrobial N-Halamine-Surface Modification of Stainless Steel

The surfaces of materials fabricated from stainless steel are challenging to functionalize with antimicrobial moieties. This work demonstrates that stainless steel surfaces can be modified with an N-halamine-based copolymer in order to obtain antimicrobial activity. In this regard, a copolymer (HACM) of 2-acrylamido-2-methy1-1-(6-methylhydantoiny1)-propane and 3-doro-2-hydroxypropyl methacrylate was synthesized and grafted onto a stainless steel surface via covalent attachment. Synthesized monomers and copolymers were charatterized by NMR, FTIR, and XPS spectral analyses. Upon treatment with dilute bleach, the stainless steel surfaces were rendered antimicrobial, possessing a sufficient amount of chlorine content and excellent stability and durability. The modified stainless steel samples inactivated 6 logs of Staphylococcus aurens and Escherichia coli 0157:H7 bacteria within 15 min of contact time. Stabilities of the coatings toward washing and UVA exposure were also studied. The stainless steel samples showed superior washing stabilities and regenerabilities. After 5 cycles of washing; there was a very minimal change in the initial chlorine contents, and the chlorine content could be recharged to its initial number of Cl+ atoms/cm(2). However, only a moderate stability of the coatings was observed after UVA irradiation. These results indicate that N-halamine precursor polymers can be facilely applied to stainless steel surfaces by covalent bonding and that robust, regenerable antimicrobial stainless steel surfaces could be prepared via the N-halamine technology. This technology exhibits potential for use in food procesSing, prevention of biofilm formation, and biomedical and health-care industries to support the prevention and reduction of cross-contamination and health-care related infections.