title: [Study on the preparation and properties of novel silica microporous antireflective coating by sol-gel process].
abstract: Silica sol was prepared by acid catalyzed sol-gel process using tetraethylorthosilicate (TEOS) as precursor and dimethyldietoxysilane (DDS) as pore-forming agent. A novel kind of monolayer microporous silica anti-reflective (AR) coating was obtained on K9 glass substrate by dip-coating technique and then heat treated at 500 degrees C. The effects of different DDS/TEOS molar ratios on refractive index, transmittance and hardness were investigated. A positive correlation was found between the transmittance and the DDS/TEOS molar ratio due to the increasing porosity. The maximum transmittance can reach 99.7% with the molar ratio of DDS/TEOS rising to 1 : 1. Meanwhile, the refractive index was found quite close to the ideal value 1.22. Nevertheless, higher molar ratio will lead to a bad film-forming property. On the other hand, the hardness of the coatings decreased with the DDS increasing but still remained more than 2 h when the transmittance reached highest. Besides, these coatings exhibit a well abrasion-resistance and excellent adhesivity. The maximum transmittance was only dropped by 0.071% and 0.112% after abrasion for 500 and 1 000 times respectively. Accelerated corrosion tests indicated that the transmittance of traditional coatings rapidly fell down to the substrate level (-92%) after immersion for 5 min, while the transmittance of our novel coating almost linearly decreased and was kept 93.2% after 56 min. In other words, the environment-resistance of our novel silica AR coating is ten times higher than that of traditional ones. The promotions of the coating performances benefit from its micropore structure (-0. 4 nm) with which water molecule can be effectively prevented. With its high transmittance, good mechanical properties and high environment-resistance, this kind of novel coating has a potential application in the field of solar glass modification to improve its anti-reflective properties.
authors.affiliation: Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China. mengying_s@163.com
authors.forename: Meng-Ying
authors.initials: MY
authors.lastname: Shang
authors.forename: Lin-Hong
authors.initials: LH
authors.lastname: Cao
authors.forename: Miao
authors.initials: M
authors.lastname: Liu
authors.forename: Xuan
authors.initials: X
authors.lastname: Luo
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Ren
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.forename: Yong-Jian
authors.initials: YJ
authors.lastname: Tang
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Jiang