Self-cleaning and antimicrobial properties of chitosan films containing Melon/TiO2 nanoparticles under indoor lighting irradiation

JULIAN RENGIFO; PAULA OSORIO-VARGAS; DANIEL ALEJANDRO MARIN-SILVA; ESTEFANIA VELEZ PEÑA; ADRIANA PINOTTI; JULIANA PEREZ OBANDO; LUIS RENE PIZZIO

Natal

Congreso; IV Iberoamerican conference on advanced oxidation technologies; 2019

Universidad Federal de Rio Grande del Norte

Visible light-absorbingTiO2 nanoparticles modified with urea (10% w/w) were successfullyincorporated into chitosan films in a ratio 70:30 chitosan:nanoparticles(CS/UTiO2-10%). Self-cleaning and antimicrobial photo-inducedactivities of films were evaluated upon actinic light irradiation by usingmalachite green dye and Staphylococcusaureus as pollutant and bacteria model respectively. Malachite green stainswere removed on the films after 72 h of continuous actinic light irradiationwhile an initial concentration of 106 CFU mL-1 of S. aureus underwent a dropping around 3logs after 3 h of continuous irradiation. Malachite green exhibitedN-demethylation byproducts and formation of benzophenones which couldcorrespond to the formation of ?OH radicals and singlet oxygen (1O2).Both reactive oxygen species (ROS) should also responsible of S. aureus inactivation. CS/UTiO2-10%films were effective removing malachite green stains after 20 days ofcontinuous light irradiation.