含Si-O-P键的减反膜结构及性能影响因素研究

采用SiO₂水溶胶(ACS)为硅源, H₃PO₄为桥联剂, H₂O₂为活化剂在玻璃表面成功制备了一种性能优异的新型减反膜。利用FTIR、XRD、FESEM、TEM、AFM对薄膜结构、形成机理及性能进行了研究, 结果表明, 在成胶过程中, H₂O₂的导入有效修复了SiO₂胶粒的表面羟基, 提高了SiO₂的反应活性; 而在焙烧过程中, H₃PO₄通过其自身脱水形成的偏磷酸链状体分别与SiO₂胶粒及玻璃基底表面的Si-OH进行了脱羟基缩聚, 构架了坚固的Si-O-P网络交联, 最终形成了稳定的磷硅酸盐凝胶网络结构, 提高了成膜质量。当n(H₃PO₄) : n(H₂O₂) : n(EtOH) : n(SiO₂)= 0.49: 0.52: 30: 1时, 制备的SiO₂减反膜在可见光区平均透光率高达98%, 硬度可达6H。

Structure of Antireflective Films with Si-O-P Bonds and Impact Factors on Its Performance

An antireflective (AR) film was successfully prepared by dip-coating on silica glass substrate. During the preparation, aqueous colloidal silica (ACS) was used as silica source, orthophosphoric acid as adhesion promoting agent and hydrogen peroxide as activating agent. The structure, formation mechanism and performance of the film were investigated by FTIR, XRD, FESEM, TEM and AFM. The hydrogen peroxide in silica sol repairs the surface Si-O^- bonds of colloidal silica particles greatly. As a result, their stabilities and reaction activities are improved. During the heat-treatment of the film, the orthophosphoric acid is firstly transformed into the chain of metaphosphoric acid and subsequently reacted with surface Si-OH from colloidal silica particles and the substrate, resulting in the formation of the numerous Si-O-P cross-linkings and the stable silicophosphate gel structure. When molar ratio of H₃PO₄: H₂O₂: EtOH: SiO₂ is 0.49: 0.52: 30: 1, the average transmittance of the film in the visible light is 98%, and the pencil hardness grade reaches 6H.