A new solvothermal post-synthesis treatment for preparing high aspect ratio magnesium aluminium layered double hydroxides (MgAl-LDHs) has been developed.Treating laurate-intercalated MgAl-LDHs in pure ethanol in an autoclave for 48 h at 150 ℃ was found to produce delaminated MgAl-LDH nanosheets with a thickness of ～2.6 nm and an aspect ratio of ～105.It is proposed that the high pressure solvothermal process promotes the insertion of ethanol molecules into the LDH interlayer space,thereby facilitating delamination.This new post-synthesis treatment provides the opportunity for a facile,large scale route to highly delaminated high aspect ratio LDHs,which might be of interest towards novel nanomaterials for energy conversion and storage.