Sustained release of iodine from a polymeric hydrogel device for water disinfection

2‐Hydroxyethyl methacrylate (HEMA) based polymeric hydrogels were synthesized by free‐radical redox bulk polymerization technique using 1% ethyleneglycol dimethacrylate (EGDMA) as crosslinking monomer and ammonium persulfate (APS) and N,N,N′,N′‐tetramethyl ethylenediamine (TEMED) as redox initiator. Polymeric hydrogel samples were loaded with solid elemental iodine. Thermal and physical characteristics of polymer before loading and after 3 months release of iodine were evaluated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). On immersing in water, different forms of iodine were released from the hydrogel device. The amount and rate of release of I− and I 3− were measured by analytical techniques. Released iodine species showed broad spectrum antimicrobial properties and release was sustained for about 120 days. Polymeric hydrogel iodine‐based system developed can be used as a device for controlled release of iodine species at concentration levels sufficient for disinfection to get potable water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3334–3340, 2007