Synthesis and characterisation of layered double hydroxide dispersions in organic solvents†
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.