title: Characterization and Mechanism for the Protection of Photolytic Decomposition of N-Halamine Siloxane Coatings by Titanium Dioxide.
abstract: N-Halamine antibacterial materials have superior inactivation activities due to oxidative chlorine species. However, N-Cl bonds and bonds between N-halamine and substrates often decompose rapidly under UV irradiation, leading to unrecoverable loss of antimicrobial activity. In this study, titanium dioxide was covalently bonded onto N-halamine siloxane poly[5,5-dimethyl-3-(3'-triethoxysilylpropyl)hydantoin] (PSPH) via a sol-gel process. Experimental testing of the chlorinated cotton fabrics treated with TiO2/PSPH demonstrated that the residual oxidative chlorine in cotton-TiO2/PSPH-Cl was still effective for inactivating bacteria after 50 washing cycles and under UV light irradiation for 24 h. Quantum mechanical calculations found that TiO2 improves the UV stability of the PSPH-Cl system by increasing the activation barrier of the C-Si scission reaction responsible for the loss of the biocidal hydantoin moiety. SEM, XPS and FTIR spectra were used to characterize the coated cotton samples. Cotton-TiO2/PSPH-Cl samples exhibited good antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli O157:H7 (ATCC 43895). The storage stability and washing stability of treated cotton fabrics were also investigated.
authors.affiliation: Key Laboratory of Eco-textiles of Ministry of Education, College of Textiles and Clothing, Jiangnan University , Wuxi 214122, Jiangsu, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Eco-textiles of Ministry of Education, College of Textiles and Clothing, Jiangnan University , Wuxi 214122, Jiangsu, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Key Laboratory of Eco-textiles of Ministry of Education, College of Textiles and Clothing, Jiangnan University , Wuxi 214122, Jiangsu, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States.
authors.forename: Stuart
authors.initials: S
authors.lastname: McFarland
authors.affiliation: Key Laboratory of Eco-textiles of Ministry of Education, College of Textiles and Clothing, Jiangnan University , Wuxi 214122, Jiangsu, China.
authors.forename: Xuehong
authors.initials: X
authors.lastname: Ren
authors.affiliation: Department of Chemistry, University of Miami , Coral Gables, Florida 33146, United States.
authors.forename: Orlando
authors.initials: O
authors.lastname: Acevedo
authors.affiliation: Department of Poultry Science, Auburn University , Auburn, Alabama 36849, United States.
authors.forename: T S
authors.initials: TS
authors.lastname: Huang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology / Q000528:radiation effects; D001424:Bacterial Infections / Q000517:prevention & control*; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000528:radiation effects / Q000627:therapeutic use; D032561:Cotton Fiber; D019453:Escherichia coli O157 / Q000187:drug effects / Q000472:pathogenicity; D006801:Humans; D006827:Hydantoins / Q000737:chemistry; D010782:Photolysis; D012833:Siloxanes / Q000737:chemistry* / Q000627:therapeutic use; D013211:Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity; D013784:Textiles / Q000382:microbiology; D014025:Titanium / Q000737:chemistry* / Q000627:therapeutic use; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D006827:Hydantoins; D012833:Siloxanes; C009495:titanium dioxide; D014025:Titanium
keywords: DFT calculations; N-halamine siloxane; UV stability; antibacterial; inorganic/organic hybrid; titanium dioxide