| Because of the special wettability of the surface,the superhydrophobic coating has a good application prospect in self-cleaning and anti-ice or fog.However,there are still many problems in the process of preparing superhydrophobic coating,such as coating dip coating film performance is poor,it is difficult to re-coating,coating adhesion and light transmittance is lower.In this paper,aiming at the problems existing in the application,the formulation of the coating and the optimization of process parameters were studied,and the super-hydrophobic coating with good film forming performance(film uniformity,recoating performance,coating adhesion)was prepared.The silica sol was modified by wet chemical method using ethanol as solvent,the cross-linking degree of commercial silica sol was enhanced by TEOS,and then the deionized water content,silica sol type,modifier type and modifier content in the coating were optimized to prepare the coating suitable for immersion coating.The results show that the coating obtained by using 17 F modified waterborne silica sol with commercial chain has better film forming performance and can be repainted3-4 times.The coating prepared by dip coating has excellent hydrophobic property,and the droplet contact Angle is greater than 160°.The coating can resist the impact of water column with a speed of3m/s for 1min,showing good adhesion.The light transmittance of the coating is 87.5-90%,with good antifouling self-cleaning ability and certain anti-condensation effect.TEOS self-hydrolyzed silica sol was synthesized by sol-gel method using ethanol as solvent,the cross-linking degree of self-hydrolyzed silica sol nanoparticles was strengthened by silane coupling agent kh550/560,and then the self-hydrolyzed silica sol was modified by 17 F or HMDS to prepare a superhydrophobic coating suitable for immersion.The results showed that the coating obtained by modifying with 17 F and adding HMDS after 24 h had good film forming performance and could be repainted for about 15 times.The coating prepared by dip coating has excellent hydrophobic property,the contact Angle of water droplets is greater than 160°,and the rolling Angle is less than 8°.The coating can resist the impact of water column with a speed of 3m/s for 2min,showing better adhesion.The light transmittance of the coating is more than 90%,with good antifouling and selfcleaning ability,the coating will not be damaged in the frosting and condensation cycle.To remove the smell of ammonia in the coating,the use of L-arginine,tetramethyl hexamethylenediamine instead of ammonia and sodium hydroxide alkaline substances,but the preparation of the coating will reduce settlement and hydrophobic,ammonia in formula that cannot be replaced by other alkaline substances,therefore can only use spin steaming method to remove the ammonia in the coating without affecting the membrane performance.In order to improve the wear resistance of the coating,the wear resistant superhydrophobic coating based on porous adhesive layer was prepared by the bottom surface composite method.PU/FEVE mixed resin was used as the primer,and iso-hexadecane as the foaming agent.When the mass ratio of PU and FEVE was 1:1,the content of iso-hexadecane was 50wt%,the foaming temperature was130℃,and the preheating time was 100 s,the composite coating on the bottom surface had good wear resistance.The experimental results show that with rubber as the wear material,the 700 rolling angles are still less than 20° under the load of 300 g.When silk is used as wear material under the same load,the wear rolling Angle of 300 times is 22°.The long-term heat resistant temperature of the coating is lower than 60℃,and the 6h heat preservation of the coating at 80℃ begins to yellow aging.In addition,the coating has good blister resistance and can be soaked for about 15 days at room temperature. |
