一种新型纳米增透防雾膜对光学镜片的表面改性

Effect of a new anti-reflection, anti-fogging nano-film on surface modification of optical glasses

背景:利用乙烯基双键的加聚反应原理对透明基材进行表面改性,可研制既能与光学玻璃等透明基材牢固连接,又具有高亲水性和高透光率的防雾材料。目的:通过表面改性的方法研制透光性高、防雾效果好的稳定光学防雾膜。方法:以正硅酸乙酯、乙烯基三乙氧基硅烷为基质,加入乙醇、盐酸、双蒸水,采用溶胶-凝胶法制备增透、高硬度防雾膜前体物。以前体物为基质,加入丙烯酸铵、甲基丙烯酸铵和过硫酸铵,并加入甲基丙烯酸β-羟乙酯、甲基丙烯酸甲酯等辅助官能团,采用加成聚合法制备纳米级增透、高硬度亲水防雾膜。以红外光谱分析仪、X射线衍射仪测定膜层结构,以紫外分光光度计测定镀膜前后材料的透光率,以扫描电子显微镜测量材料表面结构,并测量材料的粒径大小、膜层硬度和水接触角。结果与结论:亲水防雾膜中不仅存在Si-O-Si网状结构,还存在有机聚合亲水基团。镀膜透光率最高值为94.6%,提示该膜层具有良好的透光性。液态防雾材料粒径为(265.0±43.8)nm。水接触角为14.5°,显示为高亲水性材料。"铅笔法"测得膜层硬度为6H,结合度为95.1%。采用正硅酸乙酯、乙烯基三乙氧基硅烷等材料制成的Si-O-Si网状结构在乙烯基双键打开后可以连接亲水性官能团。当水滴接触防雾膜表面时会铺展开来并形成均匀的水膜,提高透光率。在保证膜层增透、高硬度的同时,还保证了光学镜片的防雾功能。该制备工艺可行性好,质量控制方法简便、可靠。

BACKGROUND： We use the addition polymerization of vinyl double bond to surface modify transparent substrate, and make a new film that has more ideal performances, such as fastened binding force, high hydrophilicity and enhanced transmittance. OBJECTIVE： To prepare a stable optical anti-fogging coating and high-quality anti-reflective characteristics by surface modification. METHODS： Anti-reflective and high-hardness Si-O-Si network structure precursor was made by tetraethyl orthoslicate, vinyl triethoxy silane, ethanol, HCl and H2O with the sol-gel method. The nano-film was prepared using addition polymerization theory, by using Si-O-Si as solvent, mixing ammonium acrylate, ammonium methacrylare and ammonium persulfate together, and using 2-hydroxyethyl methacrylate, methyl methacrylate as auxiliary functional groups. The structure was determined by fourier transform infrared spectroscopy and X-ray diffraction, the transmittance was assayed with UV spectrophotometer before and after coating, surface structure was measured by scanning electron microscopy, the particle size, film hardness and water contact angle were measured. RESULTS AND CONCLUSION： The hydrophilic anti-flogging nano-film not only had Si-O-Si network structure, but also had polymeric hydrophilic groups. The maximum transmittance was 94.6%, which mean a good transmittance of the film. The particle size of nano-film was （265.0±43.8） nm in diameter; the water contact angle was 14.5°, which showed good hydrophilicity. The coating hardness was 6 H, and the binding degree was about 95.1%. The nano-film had-CH = CH2 bond in the Si-O-Si network structure, therefore, it could connect with hydrophilic groups. As soon as the water droplet contacted the surface covered with the nano-film, it would spread over the surface, suggesting that a high transmittance surface would be achieved. Besides high transmittance and hardness, this film had other properties such as antireflection and antifogging. The preparation technology is feasible, and the quality controlling method is simple and reliable.