Self-renewal poly-Schiff base/gallium-based liquid metal composite coatings triggered via water for superior antimicrobial performance under water

Antimicrobial and antifouling coatings, containing either biocides or antibiotics, are extensively employed in medical facilities, marine engineering and various daily settings. Nonetheless, the misapplication of these substances has caused the proliferation of super-resistant bacteria and ecological destruction. While liquid metals present an encouraging option for antimicrobial purposes, the currently available technologies encounter issues associated with particle uniformity and the regulation of Ga3+ release. A water-triggered degradable polymer, namely polyurea-modified poly Schiff base polymer (PIPT), is designed and prepared successfully. The imine bond and urea group of PIPT efficiently generate and stabilize gallium-based liquid metal particles (GLPs). After the solvent evaporation, we obtain a poly-Schiff base/gallium-based liquid metal composite coating (PIPT/G) with a PIPT cover layer measuring approximately 1–2 μm. This cover layer successfully prevents both outflow and contamination of the liquid metal inside. PIPT/G coatings are easily applicable to various kinds of substrates, including fabric, glass and plastic tubes. The degradability of poly-Schiff base materials promotes self-renewal of the coating and control the contact state of water with liquid metal, regulating release of Ga3+. These bifunctional PIPT/G composite coatings exhibit >99 % pathogen eradication by combining antimicrobial action with self-renewal capabilities. This simple yet innovative coating method has the potential to produce highly effective antimicrobial surfaces.