Figure 6. The effect of precursor concentration of the morphology of the product.

(a) Under high supersaturation conditions (i.e. high precursor concentration; 83 mM of Ti(IV)-butoxide), bundles of radiating rutile crystals are formed, producing spherulitic particles. Each bundle is composed of minute rutile crystals twisted few degrees away from the common c-axis, whereas individual bundles in such a cluster appear to be linked by twinning. (b) With decreasing supersaturation (56 mM of Ti(IV)-butoxide) the alignment between the rutile becomes more perfect while their length increases. (c) On even further decrease of supersaturation (28 mM of Ti(IV)-butoxide) well-defined multilevel branched crystals of rutile are assembled through perfect lateral assembly and twinning. The samples were synthesized using 4.4 M HCl and HT treated at 180 °C for 3 hours. Illustrations show rutile clusters developed at various degrees of supersaturation.