Design And Preparation Of Wear-resistant Hydrophobic Self-cleaning Antireflection Coating

The actual use environment of solar photothermal and photovoltaic modules is relatively bad,which requires that the coating used on solar photothermal or photovoltaic modules not only has good antireflection effect,but also puts forward requirements for the wear resistance and self-cleaning performance of the coating.Therefore,the antireflection coating with superhydrophobic function has important practical value in solar energy industry components.It can not only reduce the reflection loss of incident sunlight in the process of energy conversion,but also reduce the cleaning cost of the coating and prolong the service time of the coating.In this study,three kinds of wear-resistant hydrophobic antireflection coatings with different characteristics were prepared by using different silicon raw materials and processes.The main research contents are as follows:1.The ultra clean and self cleaning Al OOH-SiO₂ antireflective coating was prepared by hydrothermal sol-gel process.A transparent and stable rod like Al OOH sol was prepared by hydrothermal reaction with aluminum isopropyl alcohol as the aluminum source and glacial acetic acid.The SiO₂sol was prepared by sol-gel method after adding PFDTES and TMOS into the sol as silica source.TEM characterization results show that the originally monodisperse rod Al OOH is connected to each other into a network after adding pfdtes and TMOS.Further research shows that the relative content of PFDTES and the length diameter ratio of rod Al OOH will affect the optical properties,self-cleaning properties and mechanical properties of the coating.Under the optimized experimental conditions of Al OOH:PFDTES:TMOS=1:0.05:0.675,a wear-resistant superhydrophobic antireflection coating was prepared by the above sol-gel pulling method.The average transmittance of the coating in the visible light range is 95%,the hydrophobic angle is 157°,and the hardness is 3 H.The coating has good friction resistance.After 40times of friction with a 500 g weight loaded on non-woven fabric,the average transmittance of the coating is only reduced by 0.43%,and the hydrophobic angle is only reduced by 16°.The antireflection coating with superhydrophobicity and wear resistance has practical outdoor application value.2.SiO₂ superhydrophobic antireflective coating was prepared by sol-gel method and TEOS-MTES as raw material.Network SiO₂ nanoparticles were prepared with TEOS-MTES as precursor and ammonia as catalyst.Then cetyltrimethoxysilane was used for hydrophobic modification.Through the hydroxyl condensation between it and network SiO₂ nanoparticles,long-chain hydrophobic methyl groups were successfully introduced.The above sol was used to prepare friction resistant and superhydrophobic antireflection coating on glass substrate.The average transmittance of the coating in the visible light range is 94.55%,and the maximum transmittance is 96.01%.The average transmittance in the visible light range is about 2.44%higher than that of the blank high borosilicate glass.The hardness of the coating reached 4 H.After using the non-woven friction coating for 40 times under the load of 500 g,the average transmittance of the coating decreased by only0.74%.The coating not only meets the practical needs of excellent wear and moisture resistance,but also has antireflection effect,which is expected to show value in practical application.3.High hardness hydrophobic antireflection coating was prepared by SiO₂hydrosol and MTES.Sol-gel method was used to prepare the SiO₂ sol and gas silica as raw materials,glacial acetic acid as catalyst and MTES with organichydrophobic functional groups as binder.The hydrophobic Si-O generated by MTES hydrolysis was combined with SiO₂hydrosol nanospheres and the surface hydroxyl of gaseous silica surface to form a network.When SiO₂hydrosol with particle size of 10-15 nm is used as the coating material,n（MTES）:n（SiO₂）=1:1,and the addition amount of nano fumed silica is 0.1 g,a dense antireflection coating can be formed.After 40times of friction on the coating surface with 500 g weight loaded on non-woven fabric,the transmittance of the coating in the visible light range is only reduced by 0.3%,and the surface Hardness of the coating is as High as7 H.The coating can be used in scenes with high requirements for surface wear resistance and hardness.