超临界流体干燥法制备纳米级TiO2的研究

本文以廉价无机盐为原料，采用溶胶-凝胶法（Sol－Gel）结合超临界流体干燥（SupercriticalFluidDrying简称SCFD）制备了纳米级TiO₂，并采用XRD、DTA－TG、TEM技术研究了Sol－Gel过程中溶液的pH值、浓度、陈化时间及SCFD技术等条件对TiO₂粒径大小的影响，实现了干燥晶化一步完成．用该方法制得的TiO₂超细粉体，粒径大都在3～6um之间，呈球形微粒，粉体晶型为锐钛矿型，并具有纯度高、热稳定性好、失重小和粒度分布均匀等特性．

Preparation of TiO2 Ultrafine Powder in Terms of SCFD Technique

Titanium dioxide ultrafine powders were prepard by sol-gel and supercritical fluid drying(SCFD) methods from cheap inorganic salts as raw materials. The ultrafine powders were characterized in terms of XRD, DTA-TG and TEM techniques. The dependence of particle size onsolution PH value, concentration, ageing time and SCFD condition was also investigated. It wasfound that the ultrafine powders so obtained eXhibit small crystallite sizes of 3-6urn, better thermal stability and less weight loss.