Characterization and Mechanism for the Protection of Photolytic Decomposition of N-Halamine Siloxane Coatings by Titanium Dioxide

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• 作者：Ying Liu ; Jing Li ; Lin Li ; Stuart McFarland ; Xuehong Ren ; Orlando Acevedo ; T. S. Huang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：8
• 期：5
• 页码：3516-3523
• 全文大小：391K
• ISSN：1944-8252

文摘

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.