S. Takenaka et al., Structural study of mesoporous titania prepared from titanium alkoxide andcarboxylic acids, J SOL-GEL S, 19(1-3), 2000, pp. 711-714
Mesoporous titania with regulated pore size as well as high specific surfac
e area was prepared from titanium alkoxide and various carboxylic acids wit
h different alkyl-chain length [CH3(CH2)(n)COOH : n = 0-20]. Although the p
ore size and pore volume of titania changed slightly at n < 10, they increa
sed with increasing the alkyl-chain length of carboxylic acid at n greater
than or equal to 10. Each carboxylic acid forms a complex with titanium alk
oxide in an organic-inorganic precursor, while the precursor prepared by us
ing carboxylic acid with n greater than or equal to 10 consists of a lamell
a-type mesophase. The interplanar distance of the lamella structure increas
es with increasing the alkyl-chain length of carboxylic acid. During calcin
ation, the lamella structure collapses together with the combustion of orga
nic moieties and titania particles crystallized to anatase aggregate to pro
vide pores. Although carboxylic acid does not act as a true template, the f
ormation of the lamella-type mesophase in the precursor plays an important
role in controlling the pore size of titania.