Surface-grafted polymer brushes with controlled properties and nanoscale thickness are ideal candidates for transparent coatings to prevent biofouling. However, maintaining long-term antibacterial performance in natural environments remains a significant challenge. The adhesion of microorganisms compromises the performance of optical devices, often forcing a choice between antibacterial activity and transparency. Reporting in Frontiers of Chemical Science and Engineering , researchers present a coating strategy that overcomes this trade-off.
The team first fabricated a poly(methacrylic acid) brush layer with a thickness of about 52 nm on a substrate. Transition metal ions such as copper and silver were then incorporated through coordination with the brush's carboxyl groups and subsequently reduced in situ using dimethylformamide, forming the metalated polymer brush coating. The final coating thickness reached about 60.07 nm for the copper-incorporated version and about 57.45 nm for the silver-incorporated version.
Advanced characterization confirmed the successful metal integration. X-ray photoelectron spectroscopy revealed the presence of both metallic and oxide states on the surface, with atomic ratios of 7.49% for copper and 7.12% for silver. Despite the metal addition, the coating maintained a high optical transmittance of approximately 86%.
The antibacterial performance proved particularly striking. The metalated polymer brush coating achieved an inhibition rate of about 99.99% against both Escherichia coli and Staphylococcus aureus, far exceeding the performance of the polymer brush alone. The coating also exhibited notable antifouling properties, showing minimal adhesion of model proteins in laboratory tests.
For practical validation, the team coated a camera lens with the copper-incorporated version and immersed it in natural outdoor water—both clear and turbid—for 31 days. Throughout the entire testing period, the lens consistently transmitted high-resolution images. The optical transmittance of the coated glass decreased by less than 2%, and the surface atomic ratio of copper showed only a slight decrease from 7.49% to 7.12%.
This work demonstrates a viable pathway toward creating durable, transparent, and antibacterial surfaces. The metalated polymer brush coating holds significant promise for applications where optical clarity and long-term resistance to biofouling are critical, including underwater imaging equipment, medical optics, and touch display interfaces.
Frontiers of Chemical Science and Engineering
Experimental study
Not applicable
Metalated polymer brush coatings with excellent transparence and antibacterial properties
5-Dec-2025