Safe NIR Light for Fast Polymers Surface Sterilization using Organic Heaters
Résumé
Sterilization approaches using UV radiation (e.g. 254 nm), dry heat and moist heat have been widely reported in the literature. In the present study, we proposed a most environmentally friendly approach for surface sterilization using safe Near-InfraRed (NIR) light to produce a strong photothermal effect using organic NIR dyes as heaters. Markedly, well selected organic dyes strongly absorbing in the NIR range have been used as stimuli responsive compounds. When excited upon NIR light, these heaters release the light energy to their surrounding environment in the form of heat. In this work, trimethylolpropane triacrylate (TMPTA) based polymers, used as benchmark materials for coatings, could reach high temperatures (> 120°C) in a very short time scale (~30 s). Using heaters containing coatings, sterilization experiments showed very good results with total annihilation of bacteria (Escherichia coli) after only 2 min of NIR irradiation. These results suggest that short irradiation flashes could be enough to sterilize contaminated surfaces. Moreover, some tests have been performed on several NIR heaters in the NIR-II range (1000-1700 nm) for a better in-depth penetration i.e. almost 200°C could be reached by polymers in less than 1 min of NIR irradiation. Therefore, NIR LED irradiation of heater-containing polymers or coatings constitutes here a robust, transportable and safe sterilization method.
Domaines
Matériaux
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