Zinc/Catechol Resin-Based Microsphere Coating for Durable Antibacterial Cotton Fabrics

Zinc oxide nanoparticles (ZnO NPs) exhibit strong and broad-spectrum antibacterial properties, making them a promising agent for textile applications. However, their weak adhesion to fibers and poor washing durability have hindered practical use. In this work, we report zinc/catechol resin-based microspheres (Zn/CFRs) synthesized via a one-pot hydrothermal route and applied to cotton fabric through a pad-dry-cure process. The resulting Zn/CFRs exhibit a monodisperse spherical morphology, with zinc ions concentrated on the surface and ZnO NPs encapsulated within the resin matrix. The finished fabric demonstrates potent, non-leaching antibacterial activity, achieving over 99.99% inhibition against S. aureus, E. coli, and C. albicans, with excellent performance retention even after 50 laundering cycles. Furthermore, we observed that catechol oxidation in the Zn/CFRs proceeds slowly under UV light, which may contribute to the durable adhesion of the coating. Moreover, the functional finishing does not compromise the fabric's tensile strength, hand feel, or breathability, which positions it favorably for scalable adoption in functional textile manufacturing.