N-ALKYLAMMONIUM INTERCALATED 2-D HYDROUS TITANATES AND THEIR THERMOTROPIC PHASE-TRANSITION

The long chain alkylammonium (CnH2n+1NH3, n = 8 similar to 18) titanat es have been prepared by reacting the 2-dimensional layered hydrous ti tanate (H2Ti4O9 . 1.2H(2)O) with the corresponding alkylammonium salt in an aqueous solutions and their thermotropic phase transition was al so observed. The intercalation reaction could be carried out successfu lly by the exchange reaction between guest molecules, where the layere d titanantes were intercalated in advance with a smaller butylammonium guest before reacting with a larger and longer alkylammonium one in o rder to reduce the steric hindrance during the intercalation reaction. The interlayer distances of the alkylammonium derivatives increase al most linearly with the number of carbon atom (Delta d/Delta n = 1.19 A ngstrom) and the interlayer alkylammonium ions form bilayer with avera ge tilting angle (theta) of approximate to 70 degrees. Thermotropic ph ase transition of the intercalated compounds were also investigated wi th DSC and high temperature XRD.