Preparation And Application Of Transparent Superhydrophobic Coating Based On Fiuorine-containing Nanoparticles

The superhydrophobic surface has broad application prospects in the fields of anti-fouling,anti-fogging,self-cleaning,antibacterial,deicing,and oil-water separation.In recent years,due to its unique properties,superhydrophobic surfaces have attracted widespread attention in scientific research and practical applications.However,conventional superhydrophobic surfaces have poor light transmittance and cannot be used on substrate surfaces that require high transparency,such as automobile rearview mirrors,airplane windshields,solar panels,etc.The light transmittance greatly limits the application range of superhydrophobic materials.Therefore,this article takes the improvement of light transmittance as the starting point,prepares a transparent superhydrophobic coating based on high fluorine-containing nanoparticles,and selects three substrates:glass,paper,and cotton to carry out related basic theories and performance studies.The main work of the paper is as follows:(1)Using glycidyl methacrylate(GMA)and perfluorooctyl ethyl methacrylate(FOEMA)as raw materials,the fluoropolymer P(GMA-r-FOEMA)was synthesized by the traditional free radical polymerization method.Characterize the polymer by Fourier Transform Infrared Spectrometer and Hydrogen Nuclear Magnetic Resonance Spectroscopy.The silane coupling agent(KH550)was used to modify nano-silica(NS),and the success of the modification was proved by Fourier Transform Infrared Spectroscopy.Explore the mechanism of KH550 modified NS and P(GMA-r-FOEMA)synthesis mechanism.(2)P(GMA-r-FOEMA)is used to construct the hydrophobic surface,and then the solution soaking method and the controlled variable method are used to determine the best construction conditions as follows:the soaking concentrations of glass,paper and cotton are 5 g/L,2 g/L,and 20 g/L,respectively,soaking time is 30 min,drying temperature is 120?,drying time is 30 min.Under the best construction conditions,the water contact angles(WCA)of glass,paper and cotton surface are 120°,143°and 148°,respectively,and the rolling angles(WSA)of paper and cotton are 7°and 21°,respectively.After modification,the Gibbs Free Energy(GFE)of the surface of glass,paper and cotton decreased by 1 88.1 dyne/cm,34.9 dyne/cm,and 58 dyne/cm,respectively.GFE and WCA have an inverse relationship.The surface of the modified substrate has good self-cleaning,wettability,acid and alkali resistance and durability.The fluoropolymer has no effect on the light transmittance of the glass.When the oil is n-hexane,the continuous separation efficiency—after the last oil-water separation is over,the next separation will be carried out immediately,and drying re-separation efficiency—after the last oil-water separation,dry the cotton used at 120? for 30 min,and then proceed to the next separation,of the modified cotton are both as high as 92%.When the oil is chloroform,the continuous separation efficiency and drying re-separation efficiency of the modified cotton are 89%and 90%,respectively.The surface of modified cotton and modified paper has obvious silver mirror phenomenon,and the modified cotton has floating phenomenon and selective adsorption.(3)Hybrid assembly of P(GMA-r-FOEMA)and MNS grafted with KH550,and then use P(GMA-r-FOEMA)/MNS to construct a transparent superhydrophobic surface.The optimal construction conditions are determined by the solution soaking method and the controlled variable method:the soaking concentration of glass,paper and cotton are 0.5 g/L,2 g/L,and 10 g/L,and the soaking time is 30 min,30 min,and 5 min,the number of soaking is 2 times,the drying temperature is 120?,and the drying time is 5 min,30 min,and 5 min,respectively.Under the best construction conditions,the WCA on the surface of glass,paper and cotton are 163°,160°and 164°,respectively,and the WSA are 2°,2°and 6°respectively.After modification,the GFE on the surface of glass,paper and cotton decreased by 202.9 dyne/cm,237.5 dyne/cm,and 59.3 dyne/cm,respectively.The surface of the modified substrate has good self-cleaning,wettability and durability.After acid-base treatment,the WCA of the substrate surface is greater than 150°.The transmittance of the modified glass was reduced by 4%,but it did not affect the actual application performance of the glass.When the oil is n-hexane,the continuous separation efficiency and drying re-separation efficiency of the modified cotton are both as high as 98%.When the oil is chloroform,the continuous separation efficiency and drying re-separation efficiency of the modified cotton are 95%and 97%,respectively.There are obvious silver mirror phenomenon,floating phenomenon and selective adsorption on the surface of modified cotton and modified paper.