Silver nanoparticle@catechol formaldehyde resin microspheres: One-pot synthesis and application for producing durable antimicrobial cotton fabrics

Silver nanoparticles (Ag NPs) are widely utilized as antibacterial agents, but they are easily agglomerated and have weak adhesion to the substrate, resulting in low stability in the performance of Ag NPs modified antibacterial fabrics. In this work, a one-pot hydrothermal synthesis of silver nanoparticle@catechol formaldehyde resin microspheres (denoted as Ag@CFR) was developed using catechol, hexamethlenetetramine, and silver salts as precursors. When the catechol to silver salt ratio was adjusted to 10:1, monodisperse microspheres were synthesized with the incorporation of Ag NPs both on the surface and within. Ag@CFR could be uniformly dispersed in water, showed very high antimicrobial activity against S. aureus, E. coli, and C. albicans, and had a comparatively low level of cytotoxicity to mammalian cells. Subsequently, Ag@CFR were uniformly deposited and firmly adhered onto the fabric surface using the pad-dry-cure method, resulting in the production of durable antimicrobial cotton fabrics. Ag@CFR-coated fabrics showed very high antimicrobial activities and laundering durability, which presented a high bacteriostatic and fungistatic rate of 99.99% against S. aureus, E. coli, and C. albicans even after 50 laundering cycles. Ag@CFR-coated fabrics maintained good tensile properties, hand feel, and air permeability while presenting superhydrophilicity during the test. This work presents a pioneering attempt to modify fabrics using CFR coatings via a facile method, which is suitable for large-scale production and holds significant potential for widespread applications in various fields.