Research On Preparation And Antibacterial Performance Of Bionic Superhydrophobic Surfaces

Metal materials are widely used in daily life.When the materials are exposed to the humid environment,floating bacteria in the environment will adhere to the surfaces of the materials.With the continuous adhesion and accumulation of bacteria,the biofilm will be formed on the surfaces,which not only causes serious biological pollution,but also has adverse effects on society,environment and economy.After billions of years of evolution,typical organisms in nature exhibit excellent superhydrophobic structures,and their excellent superhydrophobicity originates from the synergistic effect of micro-nano hierarchical structures and low-energy surfaces.The superhydrophobic surfaces by trapping the air layers can effectively reduce the contact area between bacteria and the materials and inhibit the initial bacteria from attaching to the material surfaces,which achieves antibacterial and anti-biofilm formation.In addition,the prepared superhydrophobic surfaces also have some special functions,such as anti-corrosion,anti-fouling and self-cleaning properties.The superhydrophobic surfaces with both low cost and high performance will have broad application prospect.At the same time,after experimental design and optimization,the surface morphologies,wettability,self-cleaning,antibacterial and corrosion resistance of the prepared superhydrophobic surfaces were systematically analyzed,and the mechanism of action between materials,structures and function was revealed.Inspired by the superhydrophobic surfaces of creatures,a simple spraying method has been used to prepare the biomimetic superhydrophobic coatings with long-lasting anti-corrosion performance and enhanced anti-bacterial ability on glass,PET film,paper,fabric,stainless steel and tinplate substrates.The advantage of this design lie in its low cost and and excellent superhydrophobicity.The coatings are mainly composed of epoxy resin(EP),polydimethylsiloxane(PDMS)and KH550-modified micron ZnO and nano-ZnO.The water contact angle and sliding angle of the coatings are 162.8° ± 1° and 3° ± 1°.The coatings maintain excellent liquid repellency to various types of liquids(milk,coffee,tea,juice,cola and sprite)and enhanced anti-bacterial adhesion to E.coli.Electrochemical measurements show that the prepared superhydrophobic coatings have excellent long-lasting corrosion resistance performance.Furthermore,the prepared superhydrophobic coatings also show good chemical resistance,mechanical durability and self-cleaning performance.In addition,Inspired by the superhydrophobic microstructures of purple orchid leaves,a biomimetic stable superhydrophobic surface with the micro-nano hierarchical structures and low surface energy was prepared on the stainless steel substrates through a two-step method of laser processing structures and spraying coatings.The synergistic effect of the antibacterial adhesion and the sterilization activity gives the surfaces excellent anti-bacterial ability.The superhydrophobic surfaces with the water contact angle of 161.7° ± 1° have excellent liquid repellency for various types of droplets(milk,coffee,tea,juice,cola and sprite).Tape peeling,sandpaper abrasion and grit impact tested the mechanical durability of the superhydrophobic surfaces.Moreover,the prepared superhydrophobic surfaces also exhibit excellent chemical stability against acids,alkalis and salts solution and self-cleaning properties for grits and powders.