A team from Jiangsu University of Technology, Soochow University, and Ghent University has engineered a transparent, self-healing polyurethane coating that repairs scratches under moderate heat and simultaneously inhibits bacterial growth. The material, strengthened by dynamic selenonium salts, addresses long-standing challenges in protective coatings for electronics, marine sensors, medical devices, and public surfaces. Published in the Chinese Journal of Polymer Science (DOI:10.1007/s10118-025-3414-7), the study demonstrates a coating that maintains high transparency, mechanical stability, and antibacterial function even after recycling or prolonged seawater exposure.
Polyurethane coatings are widely used to protect cars, ships, electronics, and touch surfaces, but they are prone to scratches, fouling, and microbial attachment, which degrade clarity and performance over time. Traditional self-healing films often rely on microcapsules that work only once or compromise transparency, and few combine healing with antibacterial properties. The new coating embeds selenonium salts into a polyurethane network via a one-pot synthesis and thermal curing. This dynamic chemistry allows polymer chains to rearrange under heat, giving the coating vitrimer-like reprocessability while remaining robust at room temperature.
When scratched, the coating, designated PU2-C7, healed visibly within one hour at 140 °C. With slight pressure, recovery time shortened to about 20 minutes. Even after multiple cut-and-remold cycles, the films preserved their chemical structure and mechanical behavior. Antibacterial tests showed that selenonium-containing samples dramatically inhibited E. coli and S. aureus growth, with high-loading PU3-C7 nearly eliminating colonies. Scanning electron microscopy revealed ruptured bacterial membranes, indicating a contact-killing mechanism. Optical measurements confirmed ~90–91% light transmittance, comparable to bare glass, and the coating remained clear after two weeks of simulated seawater immersion with minimal swelling. Pencil hardness reached 1H and adhesion was rated 4B–5B, meeting standards for protective coatings on devices and marine windows.
“This coating behaves like a living surface—it can recover from damage and defend itself against bacteria,” the authors explained. “The key lies in the dynamic selenonium chemistry, which allows the polymer network to reorganize during healing while keeping the surface hostile to microbes.” The technology could benefit phone screens, touch panels, underwater lenses, public facilities, medical devices, and ship equipment, where scratches and microbial contamination are daily challenges. Its high clarity means it can coat optical components without image loss, while recyclability supports circular material design.
The work was financially supported by the National Natural Science Foundation of China (Nos. 21971177 and 52503155), Natural Science Foundation of the Jiangsu Higher Education Institution of China (No. 22KJA150004), China Scholarship Council (No. 202206920034), Research Foundation Flanders (FWO) (Application 1S34725N), and other programs. The original source URL is https://doi.org/10.1007/s10118-025-3414-7. For further information, visit http://chuanlink-innovations.com.
