Novel Strategy for the Development of Antibacterial TiO2 Thin Film onto Polymer Substrate at Room Temperature

Patcharaporn Phuinthiang; Dang Trung Tri Trinh; Duangdao Channei; Khakhanang Ratananikom; Sirikasem Sirilak; Wilawan Khanitchaidecha; Auppatham Nakaruk

doi:10.3390/nano11061493

Novel Strategy for the Development of Antibacterial TiO₂ Thin Film onto Polymer Substrate at Room Temperature

Nanomaterials (Basel). 2021 Jun 4;11(6):1493. doi: 10.3390/nano11061493.

Authors

Patcharaporn Phuinthiang^{1

2}, Dang Trung Tri Trinh², Duangdao Channei³, Khakhanang Ratananikom⁴, Sirikasem Sirilak⁵, Wilawan Khanitchaidecha^{1

2}, Auppatham Nakaruk^{2

6}

Affiliations

¹ Department of Civil Engineering, Faculty of Engineering, Naresuan University, Phitsanulok 65000, Thailand.
² Centre of Excellence for Innovation and Technology for Water Treatment, Faculty of Engineering, Naresuan University, Phitsanulok 65000, Thailand.
³ Department of Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand.
⁴ Department of Science and Mathematics, Faculty of Science and Health Technology, Kalasin University, Kalasin 46230, Thailand.
⁵ Department of Community Medicine, Faculty of Medicine, Naresuan University, Phitsanulok 65000, Thailand.
⁶ Department of Industrial Engineering, Faculty of Engineering, Naresuan University, Phitsanulok 65000, Thailand.

Abstract

This work demonstrates a novel method to deposit an antibacterial TiO₂ thin film on a polymer substrate at room temperature. A combination of sol-gel and photon assistance was used in the experiment in order to avoid any thermal processes of thin film crystallization. The morphological photograph of samples indicated that the TiO₂ thin film was perfectly coated on the PVC substrate without any cracks or pinholes. Chemical analysis by EDS and XPS reported that the thin film consisted of titanium (Ti), oxygen (O), and carbon (C). The Raman spectrum proved that the thin film was the anatase phase of TiO₂ and, furthermore, that it was contaminated with carbon remaining from the photon assistance process. In addition, the optical band gap of the thin film was 3.35 eV, suggesting that the photocatalytic activity of TiO₂ should occur under UV-A radiation. The bacteria viability assay was examined using E. coli and S. typhimurium as indicator strains under UV-A irradiation (365 nm) at different times. The data from OD and CFU count revealed that >97% of bacteria were killed after 60 min of irradiation, and the bacteria were completely killed at 120 min for E. coli and 180 min for S. typhimurium.

Keywords: E. coli; S. typhimurium; antibacterial coating; disinfection surface; titanium dioxide.