Photothermal Self‐Healing Waterborne Polyurethane with Antibacterial, Hydrophobic, and Oleophobic Properties Based on Dynamic Hindered Urea Bonds

To endow polyurethane coating with photothermal self-healing, antibacterial, hydrophobic, and oleophobic properties, in this study, cellulose nanofiber coated with polydopamine and silver nanoparticles (CNF@PDA@AgNPs) and hindered urea bonds were introduced into fluorinated waterborne polyurethane as functional nanofillers and dynamic motifs, respectively. Owing to the remarkable photothermal property of CNF@PDA@AgNPs and the presence of dynamic hindered urea bonds, the photothermal self-healing fluorinated waterborne polyurethane urea (PSF-WPU) film exhibited excellent self-healing capability. Under a xenon lamp irradiation with an intensity of 100 mW/cm² for 4 h, the self-healing efficiency of its tensile strength and elongation at break reached 95.20% and 95.19% of its original properties, respectively. With the increase of CNF@PDA@AgNPs dosage, the water-oil contact angles of the PSF-WPU film increased. Furthermore, silver nanoparticles (AgNPs) as antibacterial agents endowed PSF-WPU finished fabrics with excellent antibacterial properties, with 99.37% and 90.29% against E. coli and S. aureus, respectively. This work offers a feasible approach for fabricating self-healing waterborne polyurethanes with outstanding photothermal antibacterial, mechanical, hydrophobic, and oleophobic performances that have great potential in the areas of coatings, textiles, leather, and biomedicine.