具有超亲水光催化性能的λ/4-λ/2型两层宽频增透膜的制备和性能研究

doi:10.15541/jim20180116

摘要/Abstract

摘要：

以多孔SiO₂/TiO₂复合膜为膜层材料, 采用溶胶-凝胶法制备得到λ/4-λ/2型无峰两层宽频增透膜, 此工艺制备过程简, 单且对膜层折射率要求较低, 镀制两层膜的K9基片在500~700 nm波段维持较高的透过率, 在此区间透过率平均值为99.4%, 在可见光区400~800 nm的平均透过率为99.0%。两层膜表现出优异的超亲水性能, 在无需紫外光照的条件下, 其在0.5 s的水接触角仅为2.2°, 且超亲水性能能够维持超过20 d。同时, 两层膜表现出一定的光催化降解有机污染物的能力。

关键词: 宽频增透膜, 超亲水, 光催化, 二氧化硅, 二氧化钛

Abstract:

Antireflective (AR) coatings, which can suppress the undesired interfacial Fresnel reflections, are widely used in optical devices and energy-related instruments. Conventional single-layer quarter-wave AR coatings, which only work at a single wavelength, have been seriously limited in some practical applications because of this inherent property. In this work, broadband AR coatings were designed and prepared based on the concept of λ/4-λ/2 double-layer interference film by Sol-Gel dip-coating method. Substrates (K9 glasses) coated with the double-layer films attained consistent high transmittances at 500-700 nm with an average transmittance of 99.4%, and the average transmittance at visible region was 99.0%. The λ/4-λ/2 broadband antireflective coatings were achieved without low-refractive- index materials. So high-refractive-index TiO₂ could be introduced into the double-layer films to endow the films with self-cleaning property. The double-layer films exhibited outstanding superhydrophilicity with water contact angle of 2.2° in 0.5 s, and the superhydrophilicity lasted for 20 d in the absence of UV illumination. The double-layer coatings also showed a good ability to decompose organic substances under UV irradiation. The broadband of AR coatings with photocatalysis and durable superhydrophilicity may be applied in the fields of opto- and microelectronics.

Key words: broadband antireflective coatings, superhydrophilicity, photocatalytic activity, SiO₂, TiO₂

中图分类号:

李远洋,江波. 具有超亲水光催化性能的λ/4-λ/2型两层宽频增透膜的制备和性能研究[J]. 无机材料学报, 2019, 34(2): 159-163.

LI Yuan-Yang, JIANG Bo. λ/4-λ/2 Double-layer Broadband Antireflective Coatings with Superhydrophilicity and Photocatalysis[J]. Journal of Inorganic Materials, 2019, 34(2): 159-163.

图/表 8

图1 计算机模拟得到的底层折射率为1.6的λ/4-λ/2两层膜的透过率曲线

Fig. 1 Simulated transmittance spectra of modeled double- layer coatings with the refractive index of bottom layer of 1.6

图2 制备和计算机模拟两层膜的透过率曲线与裸片的透过率曲线

Fig. 2 Transmission spectra of simulated and experimental double-layer AR coatings compared with that of bare K9 glass

图3 TiO2、硅钛复合膜和两层膜的(a)0.5 s和(b)静态接触角随时间的变化曲线

Fig. 3 Time-dependent variations of (a) 0.5 s spreading and (b) static water contact angle of TiO2, TiO2-SiO2 and double- layer films Insets: water contact angle images of the double-layer film for 0, 30 d and 60 d

图4 二氧化硅, 二氧化钛和两层膜的红外谱图

Fig. 4 FT-IR spectra of SiO2 film, TiO2 film and double-layer film

图5 同一标度下各膜层的3D-AFM形貌图

Fig. 5 AFM surface topographies of (a) TiO2 film, (b) TiO2- SiO2 composite film (20wt% TiO2), and (c) double-layer film

图6 镀有硬脂酸的两层膜在紫外光照下的红外吸收峰衰减情况

Fig. 6 Evolution of FT-IR spectra of stearic acid coated double- layer film with UV illumination

图S1 (a)硅钛复合膜的折射率随膜层中二氧化钛的含量变化曲线图 (b)不同F127含量的硅钛复合膜(20wt% TiO2)的折射率变化曲线图

Fig. S1 (a) Changes of refractive indexes of composite films as a function of TiO2 content, (b) Changes in refractive index of 20wt% TiO2 containing composite films as a function of F127 content in sols

图S2 400 ℃热处理的TiO2粉末样品的XRD衍射图

Fig. S2 XRD pattern of the TiO2 powder heat-treated at 400 ℃

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