NIR‐Responsive Polyurethane Nanocomposites Based on PDA@FA Nanoparticles with Synergistic Antibacterial Effect

At present, high‐performance antibacterial polymer materials have attracted widespread attention, possessing huge application prospects in the fields of medical and biological science, and packaging. In this work, polydopamine nanoparticles (PDA NPs) with photothermal ability and active sites are designed to adsorb fusidic acid (FA) molecules with targeted antibacterial capability; then, polydopamine@fusidic acid (PDA@FA) is introduced into the polyurethane (PU) to obtain multifunctional and antibacterial PU materials (PUDA@FA). The structures and morphologies of PDA NPs and PDA@FA are successfully characterized by Fourier transform‐infrared spectroscopy and scanning electron microscopy. With the introduction of PDA@FA, the nano‐sized reinforcement not only greatly improves the mechanical properties (tensile strength 19.31 MPa and toughness 10.6 MJ m−3) of PU film but also due to the photothermal effect of PDA NPs and the antibacterial of FA, the scavenging activities of DPPH and ABTS reach 70–85% and 55–70%, respectively. The antibacterial rate of Staphylococcus aureus reaches more than 99.9% and presents long‐term antibacterial ability. In this way, this work provides new guidance for the preparation of high‐performance PU materials with both antibacterial and anti‐oxidation properties, broadening the application scope of antibacterial materials. The plate counting method, inhibition zone test, and scanning electron microscopy are used to characterize the synergistic antibacterial properties of PUDA@FA nanocomposite film. In this regard, the incorporation of PDA@FA nanoparticles endows the polyurethane material with superior photothermal conversion, mechanical properties, and excellent antibacterial/antioxidant capacities, which have a wide range of applications in the biomedical field, photothermal, and household products.