Preparation And Applications Of Structural Antibacterial-Anti-smudge Coatings With Highly Transparent

Life is full of various stains,and to maintain a healthy and comfortable environment,anti-smudge materials that exhibit strong repellency to both water-and oil-borne smudge have become an ideal choice for people.And the existing anti-smudge materials have disadvantages,such as low optical transparency,poor wear resistance,and difficulty in long-term anti-smudge.However,the smooth polymer-based anti-smudge coating effectively overcomes the above problems,and its excellent self-cleaning,liquid repellency,and anti-graffiti performance make it have potential applications in the anti-dust of glass curtain walls of high-rise buildings,anti-corrosion of civil infrastructure,etc.Besides,the antibacterial ability expanded by incorporating antibacterial agent into the anti-smudge system enlarges the protection range of the coating effectively.The coating,which has excellent rejection effects on non-biological stains and living bacteria,is more suitable for practical application,and its strategy of preventing contamination and bacterial adhesion from the source is desired.Therefore,the preparation of such antibacterial-anti-smudge materials is of great significance.In this paper,a fluorine-free and omniphobic anti-smudge coating was prepared by introducing hydroxyl-terminated polydimethylsiloxane(PDMS)into the heavily cross-linked polyurethane system.Only 5wt%PDMS content was required to reduce the surface energy of the coating to 24.32 m J m^-2,and the prepared coating exhibited excellent wettability and self-cleaning properties.The surface of the coating was smooth and flat,and the root-mean-square roughness was only 0.406 nm,showing high optical transparency.Besides,the anti-smudge coating also endowed various excellent ink resistance to various smooth substrates(glass,wood and metal plates,etc.),and imparted super-hydrophobicity to cotton fabrics.Moreover,the anti-graffiti and anti-artificial fingerprint liquid performance of the coating provided a solution for urban graffiti and screen pollution of electronic devices.The coating still maintained the excellent wettability even after being immersed in extreme corrosive solution for 12 h,which indicated the remarkable chemical stability of the coating.Strictly,outstanding mechanical performance made it in the impact,scratch and bending still maintain a significant ink resistance,and the coating was wear-resistant.A highly transparent antibacterial-anti-smudge coating was prepared by covalently grafting small molecule antibacterial agent hexahydro-1,3,5-tris(hydroxyethyl)-s-triazine(TNO)into the original anti-smudge system.When the content of TNO was increased to 8 wt%,the prepared coating could eliminate over 98%of E.coli and S.aureus,and there was no inhibition zone around the coating,indicating that the coating was structural antibacterial material with non-leaching performance.In addition,the surface wettability of the coating decreased due to the decreased of the proportion of PDMS.However,the smooth and flat coating with a root-mean-square roughness of 0.42 nm were still highly transparent,and XPS analysis showed that the enrichment effect of PDMS segments on the surface layer was reduced,thus exposing more TNO molecular chains,which endowed the coating with excellent antibacterial-anti-smudge performance.Besides,the coating with excellent self-cleaning performance,anti-graffiti performance and anti-artificial fingerprint liquid performance showed outstanding anti-adhesion performance against bacteria,and maintained excellent ink resistance even after severe physical damage.