| The superhydrophobic phenomenon on the surface of lotus leaves has great research value and application potential in the areas of self-cleaning,anti-fouling,anti-fog,and waterproof due to its unique surface structure and performance.The micro-nano rough structure and low surface energy substances are the necessary conditions to form a superhydrophobic surface.Based on superhydrophobic surface,great progress has been made.However,building curtain walls,glass and solar cells put higher requirements on the transparency of superhydrophobic coatings.Currently,the problem of transparent superhydrophobic coatings is that the preparation conditions are harsh and has no possibility of large-scale preparation.The nano-rough structure is relatively fragile and the stability of the coating is poor.Therefore,exploring transparent superhydrophobic coating with a simple preparation method and good stability has very important research significance.In this paper,a transparent superhydrophobic coating was prepared by modifying SiO2.The research contents of this thesis are as follows:1.The interaction between silicic acid obtained by hydrolysis of TEOS,SiO2 nanoparticles gives micro-nano structure roughness to the surface of the substrate,and the low surface energy substances are bonded to the SiO2 surface by a hydrothermal reaction.A superhydrophobic coating was successfully synthesized on the glass substrate surface.By testing the wettability of the coating surface,it was found that the highest contact angle of the coating surface was 164°.Different silane coupling agents have an important influence on the hydrophobicity of the coating surface,mainly due to the difference in the reaction kinetics of HMDS(hexamethyldisilazane)and TMCS(trimethylchlorosilane).The chemical composition of the surface was tested by FT-IR,XPS.Through FE-SEM and AFM,it was found that different silica content had a significant effect on the roughness and hydrophobicity of the coating surface.With the increase of SiO2 content,the higher the surface roughness,the better the hydrophobicity.The UV-Vis shows that the prepared coating has very good light transmittance,and its maximum transmittance can reach 90%.This superhydrophobic coating has good temperature stability and can still have superhydrophobicity after being treated at low temperature to-15? and high temperature at 300?.In addition,the coating can maintain its superhydrophobicity after being treated with an aqueous solution of pH=4-10.2.The nano-SiO2 was dispersed in anhydrous ethanol,propyltrimethoxysilane was added,and after acid hydrolysis,the methyl group was successfully modified on SiO2 by stirring at room temperature.The precursor solution was coated on the substrate and successfully synthesized by heat treatment.Superhydrophobic coating;through FE-SEM,it can be seen that the content of SiO2 increases with the increasing of the surface roughness and the surface contact angle.UV-Vis shows that the prepared superhydrophobic coating has very good visible light transmittance,it can reach up to 90%.The superhydrophobic coating can maintain its superhydrophobicity at low temperature of-15? and high temperature of 200?.The prepared superhydrophobic coating in acidic and salt environment shows very good tolerability without alkali resistant.3.A transparent durable superhydrophobic coating was prepared by compounding the silane coupling agent-modified SiO2 with PDMS.Through FE-SEM and AFM,it can be seen that the greater the amount of PDMS added,the lower the roughness of the surface and the smaller the contact angle.By UV-Vis,the transparency of the coating surface is reduced after adding PDMS,and its maximum transmittance can reach 80%.The composite coating has good thermal stability and can maintain its superhydrophobic characteristics at a low temperature of-15? and a high temperature of 500?.The composite coating has good chemical stability and can maintain its superhydrophobic properties in acidic,alkaline,neutral,and salt environments.The coating has good mechanical stability and can resist water flow erosion. |
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