TiO2对中空硅减反射涂层硬度的影响

目的 提高中空硅减反射(AR)涂层的硬度.方法 采用溶胶-凝胶法制备中空二氧化硅纳米微球(HSNs)胶体溶液,通过异丙醇钛(TTIP)的水解缩合作用,在HSNs表面沉积纳米TiO2后,制备HSNs@TiO2胶体溶液.将HSNs@TiO2胶体溶液与酸性硅溶胶(ACSS)复合,制备HSNs@TiO2/ACSS减反射液,通过旋涂法在玻璃基板上制备相应的AR涂层.通过特高分辨率场发射扫描电子显微镜、高分辨透射电子显微镜和原子力显微镜对HSNs和HSNs@TiO2纳米粒子的形貌进行分析,通过紫外-可见分光光度计和纳米压痕仪对HSNs/ACSS AR涂层和HSNs@TiO2/ACSS AR涂层的透射率、硬度和弹性模量分别进行分析.结果 纳米TiO2沉积在HSNs表面后,减反射液中HSNs@TiO2纳米粒子的粒径较HSNs粒径增大1～30 nm不等.由HSNs@TiO2/ACSS减反射液制备的AR涂层表面颗粒及团簇明显,表面粗糙度(RMS)可达9.61 nm,远高于HSNs/ACSS AR涂层的3.62 nm.含有较大粒径HSNs@TiO2纳米粒子的HSNs@TiO2/ACSS AR涂层使玻璃基板在550 nm波长处的透射率增加1.3％,低于HSNs/ACSS AR涂层的增加值2.8％.纳米TiO2沉积之前,HSNS/ACSS AR涂层的硬度和弹性模量分别为2.3 GPa和56.3 GPa,纳米TiO2沉积之后,HSNs@TiO2/ACSS AR涂层的硬度和弹性模量分别为3.3 GPa和55.2 GPa,AR涂层的硬度显著提高.结论 溶胶-凝胶法在HSNs上沉积纳米TiO2后,可有效提高AR涂层的硬度,因此AR涂层的环境适用性有望得到进一步提高.

Effect of TiO2 on the Hardness of Hollow Silica Antireflection Coating

The purpose is to improve the hardness of hollow silica antireflection (AR) coatings. In this paper, a colloidal solution of hollow silica nanospheres (HSNs) is prepared by sol-gel method, and HNSs@TiO2 colloidal solution is prepared by depositing nano-TiO2 on the surface of HSNs through hydrolysis and condensation of titanium isopropoxide (TTIP). The HSNs@TiO2/ACSS AR solution is prepared by mixed the HSNs@TiO2 colloidal solution and acidic silica sol (ACSS). The morphology of HSNs and HSNs@TiO2 nanoparticles are analyzed by ultra-high resolution field emission scanning electron microscope, high-resolution transmission electron microscope and atomic force microscope. The transmittance, hardness and elastic modulus of HSNs/ACSS AR coating and HSNs@TiO2/ACSS AR coating are analyzed by UV-visible spectrophotometer and nanoindenter respectively. After the nano-TiO2 is deposited on the surface of HSNs, the particle size of the HSNs@TiO2 nanoparticles in antireflection liquid increased by 1~30 nm compared with the particle size of the HSNs; Particles and clusters on the surface of AR coating that prepared by HSNs@TiO2/ACSS AR liquid are obvious, and the surface roughness (RMS) of the AR coating could reach 9.61 nm, which is much higher than 3.62 nm of HSNs/ACSS AR coating; HSNs@TiO2/ACSS AR coating with larger HSNs@TiO2 nanoparticles increased the transmittance of glass at 550 nm by 1.3%, which is lower than 2.8% of HSNs/ACSS AR coating; Before the nano-TiO2 deposited, the hardness and elastic modulus of the HSNS/ACSS AR coating are 2.3 GPa and 56.3 GPa, respectively, the hardness of the AR coating is significantly improved after the nano-TiO2 deposited, the hardness and elastic modulus of the HSNs@TiO2/ACSS AR coating are 3.3 GPa and 55.2 GPa, respectively. The nano-TiO2 deposited on HSNs by sol-gel method could effectively improve the hardness of AR coatings, so the environmental applicability of AR coatings is expected to be further improved.