Synthesis and characterisation of layered double hydroxide dispersions in organic solvents

Abstract

Aqueous Miscible Organic Solvent Treatment (AMOST) Mg₃AlCO₃–LDHs have been prepared using twelve different (AMO) solvents. We find that the AMOST process produces significant changes to the crystallinity, morphology, thermal behaviour and dramatically increases the surface areas of the LDHs compared to conventional LDHs. Remarkably AMO–LDHs platelets are now hydrophobic and can be dispersed in a range of organic liquids. Clear dispersions of AMO–Mg₃AlCO₃–LDHs are observed in aromatic solvents. Overall, we found that the optimum AMO–Mg₃AlCO₃–LDHs organic solvent dispersions are obtained using 1-propanol as a treating solvent and ethyl benzene as the dispersion solvent. This system produces a monophasic dispersion at loading up to 140 g L⁻¹ of Mg₃AlCO₃–LDH in ethyl benzene. At a maximum loading of 160 g L⁻¹ Mg₃AlCO₃–LDH this mixture becomes a thick monophasic gel.