Research On Preparation Technology And Strengthening Mechanism Of Wear Resistant Superhydrophobic Coatings

The application and development of superhydrophobic coatings in the aspects of self-cleaning,anti-condensation,anti-icing,oil/water separation have attracted much attention from domestic and foreign scholars,but their poor mechanical stability significantly reduces the use effect and life and restricts the practical application in these fields.Enhancing the mechanical wear resistance of superhydrophobic surfaces to effectively prolong the service life is one of the important topics in the field of superhydrophobic research.In this paper,through the introduction of resin primer,the strengthening effect of resin composition,ratio and inorganic particle composite on the superhydrophobic coating was explored.A series of superhydrophobic coatings with excellent mechanical stability were prepared,and the strengthening mechanism and model of superhydrophobic nano composite coatings were proposed.The practical application of anti-condensation and anti-icing provides theoretical basis and technical guidance.Based on the single resin primer composite technology,fluorocarbon resin,ethylene vinyl acetate resin,polyurethane resin,epoxy resin and water-borne acrylic resin are used as adhesive primers.The mechanical wear resistance of the superhydrophobic nano coating is effectively enhanced by adjusting the curing time and concentration of the primer and the type and content of the added powder.The results show that the sliding angle of the superhydrophobic nano composite coating prepared with epoxy micaceous iron resin as adhesive primer remains less than 10 degrees after 70 times hand grinding,and the sliding angle remains below 20 degrees after hand grinding for 120 times.The surface sliding angle of the 911 polyurethane with 2% silicon micro powder is higher than 10 degrees for more than50 times.When the silicon micro powder content increases to 100%,the sliding angle remains below 10 degrees after the surface hand grinding 100 times.Based on the blending resin primer composite technology,fluorocarbon/ethylene-vinyl acetate resin,fluorocarbon/polyurethane resin,polyurethane resin/ethylene-vinyl acetate resin as adhesive primers were used respectively,and the mechanical wear resistance of superhydrophobic nano coating was effectively enhanced by changing the content of adding micro powder.The results show that the super hydrophobic nano composite coating prepared by adding 10% silicon micro powder to the fluorocarbon/polyurethane blend primer still maintains the sliding angle less than 10 degrees after 100 times hand grinding.The surface sliding angle of fluorocarbon/ethylene-vinyl acetate resin with 2% silicon powder more than30 times is higher than 10 degrees.When the content of silicon micro powder increases to100%,the sliding angle remains below 10 degrees after hand grinding for 70 times.By means of wear resistance,thermal stability and chemical stability test and surface morphology characterization,the strengthening mechanism of resin composite technology for superhydrophobic nano coating was systematically explored.The results showed that the slid angle is less than 10 degrees when the superhydrophobic nanocomposite coating prepared with FEVE/PU mixed resin as adhesive primer were kept on the surface after 30 cycles of grinding,30 kPa water impact 200 min,100 g/L sand washing 90 min,200 ℃ treatment 2 h,freeze-thaw cycle 25 cycles,soaking 24 h in pH=1-14 solution or soaking 2 h in various organic solvents in pH=1-14 solution,which shows the excellent surface stability.In addition,the superhydrophobic nanocomposite coating prepared with FEVE/EVA or epoxy iron as adhesive primer also has the same surface stability,and the surface superhydrophobicity remains unchanged after 6 months of outdoor placement.The results show that the superhydrophobic nano coating can be firmly bonded on the substrate through the resin composite technology,and the nano coating is further protected by the addition of micro powder particles,thus the roughness of the surface is not easily destroyed and its wear resistance is improved.Finally,we also explore the application of superhydrophobic nanocomposite coating on oil and water separation,surface anti-icing and condensation heat transfer in air conditioning heat exchanger.