Study On The Preparation And Performance Of Modified SiO₂ Hollow Sphere Sol And Its Antireflection Film

In recent years,issues such as environmental pollution and energy crisis have received increasing attention.Solar energy is a kind of clean energy,so its development and utilization are of great significance.However,it has been confirmed that glass widely used in solar devices has a reflectivity(loss rate)of more than 8% to light,leading to a significant energy loss.Therefore,the study of antireflective(AR)coatings has been a significant research subject for the effective utilization of solar energy.The hollow silica nanospheres(HSNs)AR coatings has important application value due to its high permeability.But for outdoor use,the anti-reflective film should also have good mechanical properties and weather resistance.In this paper,the HSNs AR coatings were prepared by using the HSNs sols to hybridize the modified acid-catalyzed silica(ACS)sols.In this paper,the HSNs sols,ACS sols and modified ACS sols were prepared by sol-gel method.The AR coatings were prepared by dipping and pulling method,and the performance of the AR coatings was characterized by ultraviolet-visible spectrophotometer,field emission scanning electron microscope(SEM),transmission electron microscope(TEM),energy spectrometer and video contact angle analyzer.With the analysis,the specific experimental content and conclusions are as follows:In this paper,PAA was used as the template and TEOS was the silicon source.Because PAA is soluble in water,the template was removed by centrifugal water washing to obtain a complete HSNs structure.The effects of the amount of PAA,ammonia and TEOS and the reaction temperature on the performance of HSNs sols and HSNs AR coatings were studied.It was found that the changes of various factors would reduce the optical performance of the AR coatings.The morphology and performance of the anti-reflection film were characterized.The results showed that the peak value of the transmission of the AR coatings prepared can reach99.1%,but its hardness is 1H.The HSNs AR coatings has good optical properties,but the mechanical properties and weather resistance are poor.In this paper,ACS sols were prepared,and it was found that HCl as a catalyst can affect the performance of AR films by controlling the rate of TEOS hydrolysis.The change of aging time will change the viscosity of the sols,which will affect the performance of the anti-reflection film.The peak value of the transmission rate of the ACS AR coatings is only95.0%.Therefore,in order to improve the transmission rate of the AR coatings,DDS is used as a pore-forming agent to modify the ACS AR coatings.The factors which affected the performance of modified ACS sols and modified ACS AR films were also analyzed.After characterizing the morphology and performance of the modified ACS AR coatings,it is concluded that the peak transmittance can reach 97.7%.Interestingly,the hardness was more than 6H and the transmittance did not decrease after the weathering test.Therefore,after using DDS to modify the common ACS AR coatings,its optical performance is significantly improved and has good mechanical properties and weather resistance.Because the HSNs AR coatings has good permeability,and the modified ACS AR coatings has high mechanical properties,the modified HSNs AR coatings were prepared by mixing the two sols in different proportions.The transmittance peak values were 98.9%,98.6% and 98.0% and the hardness values were 3H,6H and more than 6H while the ratios between the HSNs and the modified ACS sols were 9:1,8:2 and 7:3,respectively.The addition of modified ACS sols will reduce the optical performance of the AR coatings,but will improve the scratch resistance,adhesion and friction resistance of them.Meanwhile,the pores on the surface of the AR coatings can easily absorb the moisture and pollutants,the weather resistance of the coatings is also improved.