A tetrabutylammonium–H2Ti4O9·xH2O intercalation compound was obtained by a guest exchange reaction between tetrabutylammonium hydroxide and an ethylammonium–H2Ti4O9·xH2O intercalation compound, and its dispersion state in aqueous and non-aqueous solutions were studied. Spontaneous exfoliation of H2Ti4O9·xH2O into colloidal nanosheets occurred when the tetrabutylammonium–H2Ti4O9·xH2O intercalation compound was dispersed in water, methyl alcohol, isopropyl alcohol, acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, and propylene carbonate, while exfoliation did not occur in tetrahydrofuran. A tetrabutylammonium–H2Ti4O9·xH2O film was obtained by a reassembly process by casting the colloidal suspension containing exfoliated nanosheets, while a H2Ti4O9·xH2O film was directly obtained by electrophoretic deposition. Thermal treatment of the electrophoretically deposited film led to an oriented TiO2(B) film with the (0k0) planes lying perpendicular to the substrate.
