Light-controllable antibacterial composite films based on modified waterborne polyurethane

Abstract

Economical and eco-friendly antibacterial functional materials with smart responses are desirable for numerous applications. Here, novel kind of light-controllable switch self-release reactive oxygen species (ROS) functional composite films based on waterborne polyurethane with photoinduced response are developed. A photoactive 3,3′-benzophenone dicarboxylate polyethylene glycol-4,4′dicarboxylic acid (BPPGA) chain extender is introduced into the framework of WPU to increase its solubility. The functionalized WPU releases ROS when irradiated by ultraviolet light. The photochemical reactions, ROS generation, and antibacterial activity of WPU films with different BPPGA contents are investigated. The frontier molecular orbitals and energy gap of the films are calculated using density functional theory at the B3LYP/6−31 G (d) level. The thermal properties, hydrophilicity, and mechanical properties of the WPU films are evaluated. The BPPGA-modified WPU films exhibit excellent photoinduced antibacterial activity against S. aureus and E. coli through ROS generation; the film with a BPPGA content of 30 % decreased S. aureus and E. coli concentrations by 99.57 % and 99.87 %, respectively. The light-controllable functional films have great potential as antibacterial composites coatings on textile surfaces.