摘要： 为满足隔热涂料拥有高近红外反射率的同时还具备较低的导热性能的需求，研发了一种优秀的隔热填料：中空 TiO₂微球。中空 TiO₂微球空腔结构可储存大量空气，使得导热系数较低，同时壳层结构对红外线具有较强反射能力，是理想材料之一。以自制粒径约 340 nm单分散 SiO₂微球为硬模板，采用牺牲模板法在最优条件下成功制备粒径约 510 nm，壳厚 120 nm，空腔尺寸 260 nm左右，分散较均匀的中空 TiO₂微球。探究氨水浓度、反应时间对 SiO₂微球粒径影响，得出适宜反应时间为 2h，且氨水浓度在一定范围内增大， SiO₂粒径随之增大。研究了水热时间、温度、蚀刻液种类对中空 TiO₂微球形貌的影响，其中 50~60 ℃ NaOH溶液蚀刻 1h最适宜。测试了中空 TiO₂微球在 300~ 2 500 nm的反射率， 400~1 350 nm内反射率维持在 90%。用中空 TiO₂微球制备隔热涂料，隔热性能比用钛白粉、空心玻璃微珠制得的隔热涂料好，隔热温差达 10 ℃左右。

关键词: 中空 TiO₂微球；牺牲硬模板法；水热碱蚀刻；隔热涂料

Abstract: To meet the requirement of high near-infrared reflectance and low thermal conductivity of thermal insulation coatings，an excellent thermal insulation filler，hollow TiO₂ microspheres，had been developed. The hollow structure of TiO₂ microspheres could store a large amount of air，resulting in low thermal conductivity，while the shell layer structure had a strong infrared reflection ability. Using self-made monodisperse SiO₂ microspheres with a particle size of about 340 nm as the hard template，the hollow TiO₂ microspheres with a particle size of about 510 nm，a shell thickness of 120 nm，and a cavity size of about 260 nm were successfully prepared using the sacrificial template method under optimal conditions. The dispersed TiO₂ microspheres were relatively uniform. By exploring the effects of ammonia concentration and reaction time on SiO₂ microspheres，it was found that the appropriate reaction time was 2 hours，and as the ammonia concentration increased within a certain range，the SiO₂ particle size also increased. The effects of hydrothermal time，temperature，and type of etching solution on the morphology of hollow TiO₂ microspheres were studied，and 50-60 ℃ NaOH solution etching for 1 hour was the most suitable. The reflectivity of hollow TiO2 microspheres was tested at 300-2 500 nm，and the reflectivity remained at 90% within400-1 350 nm. Thermal insulation coatings prepared with hollow TiO₂ microspheres had betterthermal insulation performance than using titanium dioxide and hollow glass microspheres， with a thermal insulation temperature difference of about 10 ℃.

Key words: hollow TiO₂ microspheres；sacrificial hard template method；hydrothermal alkali etching；thermal insulation coating

中图分类号: 

• TQ637. 6