Step-wise Anion-Exchange in Layered Double Hydroxide Using Solvothermal Treatment

Synthetic layered double hydroxides (LDHs), [Mg₄Al₂(OH)₁₂]CO₃·nH₂O, were prepared in the submicron size of plate-like polycrystals. Anion-exchange reactions with various linear dicarboxylic acids were performed to produce LDH/organic hybrid materials by solvothermal treatment in toluene. X-ray powder diffraction spectra for the products indicated that the interlayer spacings of LDHs remarkably changed, up to 20 A when 1,10- decanedicarboxylic acid anions were intercalated as an organic guest. Dicarboxylates-LDHs samples could be also re-exchanged consecutively with other dicarboxylic acids or carbonate without serious destruction of layer structure under the scanning electron microscopic observation