纳米二氧化钛粉体表面的吸附特征及其对粉体分散性的影响

以四氯化钛(TiCl4)为原料,采用3种不同的沉淀剂制备了纳米二氧化钛粉体.用TG-DTA和FT-IR对前驱体进行了分析.结果表明,不同沉淀剂导致粉体表面状态不同.以乙酸和尿素为沉淀剂的粉体表面不仅沉淀剂可以形成化学吸附,水分子也参与反应并在粉体表面形成-OH基团,而以EDTA为沉淀剂的粉体表面只吸附沉淀剂.煅烧后,用TEM对颗粒形貌进行了表征.实验发现,以EDTA为沉淀剂制备的粉体分散性优于其他沉淀剂制备的二氧化钛颗粒.这些差异主要是由于沉淀剂的性质及其在粉体表面的吸附状态不同.

Surface adsorption characteristics of nano-titania colloid particles and its influences on the dispersity of nano-titania powders

TiO_2 Nano-powder was fabricated by hydrolysis-sediment process, using TiCl_4 as starting material. The samples prepared by acetic acid, urea and EDTA were characterized by FT-IR and TG-DTA. The results indicated that the structure difference of nano-titania particles surface is attributed to the different property of precipitants. When using acetic acid and urea as precipitants, the precipitants along with water can be adsorbed on the surface of nano-titania particles, while using EDTA as precipitants, only the precipitant can be adsorbed on the surface of nano-titania particles. After calcination, the samples were also characterized by TEM. The results showed that the dispersity of nano-titania particles prepared by EDTA is much better than that of particles prepared by other precipitants.