Sugimoto T, Okada K, Itoh H
Institute for Advanced Materials Processing, Tohoku University, Katahira 2-1-1, Aobaku, Sendai, 980-77, Japan
J Colloid Interface Sci. 1997 Sep 1;193(1):140-3. doi: 10.1006/jcis.1997.5037.
Uniform spindle-type titania (TiO2) particles were prepared by a novel gel-sol method. A mixed solution of titanium(IV) isopropoxide and triethanolamine at molar ratio 1:2 prepared in a drybox was mixed with doubly distilled water to make the final concentration of titanium(IV) 0.50 mol dm-3. The mixture was further mixed with an equal volume of 2.0 mol dm-3 ammonia solution, and the resulting solution was aged for 24 h at 100°C. By this aging a highly viscous gel was formed, but there was no sign of nucleation of titania at this stage. The gel was then aged at 140°C for 3 days to nucleate and grow the titania particles. The gel network formed in the first aging played a decisive role in the second aging to produce the uniform particles of titania, as a reservoir of the metal ions to lower the supersaturation for preventing extensive nucleation and as an anticoagulant fixing the growing particles in the matrix. The product was identified by XRD as anatase particles elongated in the direction of the c-axis. The aspect ratio, as well as the size of the resulting particles, was reduced as the concentration of ammonia was decreased. Copyright 1997Academic Press
采用一种新型凝胶 - 溶胶法制备了均匀的纺锤形二氧化钛（TiO₂）颗粒。在干燥箱中制备的摩尔比为1:2的异丙醇钛和三乙醇胺混合溶液与双蒸水混合，使钛（IV）的最终浓度为0.50 mol dm⁻³。将该混合物进一步与等体积的2.0 mol dm⁻³氨水溶液混合，所得溶液在100℃下老化24小时。通过这种老化形成了高粘性凝胶，但在此阶段没有二氧化钛成核的迹象。然后将凝胶在140℃下老化3天以使二氧化钛颗粒成核并生长。在第一次老化中形成的凝胶网络在第二次老化中对产生均匀的二氧化钛颗粒起决定性作用，作为金属离子的储存库以降低过饱和度以防止大量成核，并作为抗凝剂将生长的颗粒固定在基质中。通过XRD鉴定产物为沿c轴方向拉长的锐钛矿颗粒。随着氨浓度的降低，所得颗粒的长径比以及尺寸减小。版权所有1997学术出版社
