TiO_(2)对中空硅减反射涂层硬度的影响

Effect of TiO_(2) on the Hardness of Hollow Silica Antireflection Coating

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TiO_(2)后,制备HSNs@TiO_(2)胶体溶液。将HSNs@TiO_(2)胶体溶液与酸性硅溶胶(ACSS)复合,制备HSNs@TiO_(2)/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@TiO_(2)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@TiO_(2)/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TiO_(2)沉积在HSNs表面后,减反射液中HSNs@TiO_(2)纳米粒子的粒径较HSNs粒径增大1~30 nm不等。由HSNs@TiO_(2)/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@TiO_(2)纳米粒子的HSNs@TiO_(2)/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TiO_(2)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TiO_(2)沉积之后,HSNs@TiO_(2)/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TiO_(2)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。

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@TiO_(2) colloidal solution is prepared by depositing nano-TiO_(2) on the surface of HSNs through hydrolysis and condensation of titanium isopropoxide(TTIP).The HSNs@TiO_(2)/ACSS AR solution is prepared by mixed the HSNs@TiO_(2) colloidal solution and acidic silica sol(ACSS).The morphology of HSNs and HSNs@TiO_(2) 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@TiO_(2)/ACSS AR coating are analyzed by UV-visible spectrophotometer and nanoindenter respectively. After the nano-TiO_(2) is deposited on the surface of HSNs, the particle size of the HSNs@TiO_(2)nanoparticles in antireflection liquid increased by 1~30 nm compared with the particle size of the HSNs;Particles and clusterson the surface of AR coating that prepared by HSNs@TiO_(2)/ACSS AR liquid are obvious, and the surface roughness (RMS) ofthe AR coating could reach 9.61 nm, which is much higher than 3.62 nm of HSNs/ACSS AR coating;HSNs@TiO_(2)/ACSS ARcoating with larger HSNs@TiO_(2) 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-TiO_(2) deposited, the hardness and elastic modulus of the HSNS/ACSS AR coatingare 2.3 GPa and 56.3 GPa, respectively, the hardness of the AR coating is significantly improved after the nano-TiO_(2) deposited,the hardness and elastic modulus of the HSNs@TiO_(2)/ACSS AR coating are 3.3 GPa and 55.2 GPa, respectively. The nano-TiO_(2)deposited on HSNs by sol-gel method could effectively improve the hardness of AR coatings, so the environmental applicabilityof AR coatings is expected to be further improved.