中空TiO_2微球的制备及对聚丙烯酸酯薄膜性能的影响

采用阳离子聚苯乙烯微球作为模板,钛酸四丁酯为钛源,氨水为催化剂,制备了中空TiO_2微球.采用X射线衍射、扫描电镜及比表面测定仪对其形貌和结构进行了表征,并考察了模板粒径、钛源用量以及催化剂用量对中空TiO_2微球形貌的影响.通过物理共混法将其引入至聚丙烯酸酯乳液中并成膜,研究了复合薄膜的保温性能、抗紫外性能及力学性能.结果表明,锐钛矿相中空TiO_2微球模板粒径、钛源用量以及催化剂用量影响中空TiO_2微球的空心尺寸、壁厚及壳层致密性.中空TiO_2微球可显著提升聚丙烯酸酯薄膜的保温性能、抗紫外性能和力学性能.采用不同粒径的模板制备的中空TiO_2微球对复合薄膜的各项性能均有影响,其中模板粒径为140 nm时复合薄膜性能最优,光反射率提升63%,导热系数降低27%,且在波长小于360 nm范围内,紫外透过率几乎为0,抗张强度增加100%,断裂伸长率提升62%.

Fabrication of Hollow TiO2 Spheres and Effect on Properties of Polyacrylate Film

Hollow TiO2 spheres were prepared using cationic polystyrene microspheres as templates, tetrabutyl titanate as titanium source and ammonia as catalyst. The morphology and structure were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Teller analysis. The influence of template size, titanium source and catalyst dosage on the morphology of hollow TiO2 spheres were studied. Then, the hollow TiO2 spheres were introduced into polyacrylate emulsion by physical blending method. The thermal insulation, UV-shielding and mechanical performance of composite films were investigated. As a result, the anatase phase hollow TiO2 spheres were obtained. The hollow size, thickness and compactness of the shell of hollow TiO2 spheres were influenced by the template size, titanium source and catalyst dosage. Hollow TiO2 spheres as filler can enhance the thermal insulation, UV-shielding and mechanical performance of polyacrylate film, significantly. At the same time, it was proved that the hollow TiO2 spheres prepared with different size templates have effects on the performance of the composite films. In which, the properties of the composite film containing the hollow TiO2 spheres prepared with template of 140 nm was optimal. The reflectivity was improved about 62.2%, the thermal conductivity was decreased by 17. 71%, and the ultraviolet transmittance was almost zero under 390 nm wavelength.