Fabrication And Properties Of Superhydrophobic Surface Through The Sol-Gel And Electrodeposition Methods

Superhydrophobic phenomena are widely found in nature,such as lotus leaf,rose petals,water strider legs and shark skin,whose organs have special wetting properties.Inspired by the superhydrophobic phenomena of these flora and fauna,the exploration and research of bionic superhydrophobic surface has become a hot spot in recent years.Benefit from the special non-wetting of super-hydrophobic surface to water,superhydrophobic surface has important application value in self-cleaning,fluid drag reduction,anti-icing,anti-bio-fouling,anti-corrosion and oil-water separation.Though have the preparation technologies of superhydrophobic surface been developed.There are still many problems,including the mechanical stability,physical and chemical stability and thermal stability of the hydrophobic surface,are an urgent need to be solved.Super-hydrophobic surface of the current preparation method has a complex process,high cost,harsh conditions and other shortcomings,not suitable for large-scale production.Therefore,how to improve the quality of superhydrophobic surface process,reduce production costs,simplify the process are the current research hotspot in the field.The main contents of this thesis are as follows:Firstly,the sol-gel method was used to prepare the transparent superhydrophobic surface.Multi-layer network structure were formed through the hydrolysis and condensation of methyl triethoxysilane using MTES as the polymerization monomer,GO as the main film-forming material.The micropores on the coating surface were formed by the solvent methanol evaporation.Then the rough structure of transparent superhydrophobic surface was formed.Combined with the-CH3 in coating itself,transparent super-hydrophobic surface were prepared on the glass substrate.The effects of different ratios of MTES and GO on the contact angle of transparent superhydrophobic surfaces were investigated.It was found that the optimum performance was obtained when the volume ratio of MTES and GO aqueous solution(C = 10 mg/mL)was 10: 4 while the water contact angle(WCA)of transparent superhydrophobic surface reached 154 °.The results of scanning electron microscopy(SEM)show that the spherical particles were formed on the transparent superhydrophobic surface and rough structure was constructed by siloxane polycondensates.The acid and alkali resistance of the transparent superhydrophobic surface was investigated.The results showed that the WCA values of the transparent superhydrophobic surface reached 153°?152°? 152° while immersed in aqueous solution with pH=1,pH=14 and 3.5 wt.% NaCl solution with pH=7,respectively.It indicated that the prepared transparent superhydrophobic surface had a good acid and alkali resistance.Furthermore,the oil-water separation performance of prepared sponge-based superhydrophobic surface was studied.The results showed that the amount of n-heptane was about 47.6 times of that of the siloxane polycondensate.It indicated that the prepared sponge-based superhydrophobic surface had a very excellent oil-water separation performanceSecondly,stainless steel mesh was used as the substrate to fabricate copper plated superhydrophobic stainless steel mesh via an electrodeposition method.0.1 mol/L CuSO4 and 0.01 mol/L H2SO4 solution were used as the plating solution.Rough structures of copper plated stainless steel mesh were prepared by constant current method successfully.Then copper plated superhydrophobic stainless steel mesh was prepared by modified with n-octadecyl(ODT).The effects of different current density and electrodeposition time on the performance of superhydrophobic stainless steel mesh were investigated.It was found that the optimal performance stainless steel mesh was got and its WCA value reached 153° while electroplated at a current density of 0.1 A/cm2 for 35 s.The results of SEM observation showed that the petal-like micro-nano scale rough structures were successfully constructed on the surface of stainless steel mesh by electrodeposition method.The mechanical stability of the superhydrophobic stainless steel mesh was explored.It was found that the WCA value of stainless steel mesh was still above 140° while the sliding angle was below 10° when rubbed 80 cm on the sandpaper under the pressure of 50 g weight,which showed that the prepared copper plated superhydrophobic stainless steel mesh had good mechanical stability.The corrosion resistance of the stainless steel mesh was investigated by electrochemical impedance spectroscopy(EIS).The corrosion potential and corrosion current of the prepared copper plated superhydrophobic stainless steel mesh were 1/2 and 1/6 of the blank stainless steel mesh respectively.It indicated that the corrosion resistance had been greatly improved through electrodeposition and ODT modification process.Furthermore,the oil-water separation performance of prepared copper plated superhydrophobic stainless steel mesh was explored.The results showed that the separation efficiency of the mixture of dodecane and water reached 96%,which indicated that the prepared copper plated superhydrophobic stainless steel mesh had excellent oil and water separation performance.