A robust, room-temperature curable and molecular-level superhydrophobic coating with excellent antibacterial and antifouling properties

Abstract

This work proposed a novel molecular-level superhydrophobic coating. The superhydrophobicity was achieved by using polydimethyl siloxane (PDMS) as the low-energy substance and nanoparticles of metal organic framework (MOF) as the roughness-improving components. The nanoparticles were synthesized by using 2-aminoterephthalic acid as the ligand to obtain molecular level amination, and PDMS was molecular-level aminopropyl terminated prior to the coating preparation. These made the coating molecular-level superhydrophobic. Epoxy resin and triclosan were further used to improve the mechanical strength and to ensure the bactericidal property, respectively. These four components (NH2-PDMS, NH2-MOF, epoxy resin, triclosan) were cured in one-step at room temperature by using a “jointly shared” hexamethylene isocyanate (HDI) as the crosslinker via chemical interaction between isocyanate group in HDI and amino groups in NH2– PDMS and in NH2-MOF and hydroxyl groups in epoxy resin and in triclosan. The chemical immobilization of triclosan in the coatings avoids its leaching and is friendly to the environment. The as-prepared superhydrophobic coatings are room temperature curable, fluorine-free and have excellent wear-resistant, antibacterial and antifouling performance. The coating can be prepared by simply brushing and spraying, and has a potential for large-scale industrial application.