An integrated strategy for the extraction and solidification of Th(IV) ions from aqueous HNO3 solution based on self-assembly triggered by [DODMA]+[DGA]- ionic liquids

•The novel [DODMA][DGA] ILs were designed and synthesize for the first time.•The ILs were applied to extraction and solidification of Th(IV) by self-assembly.•The [DODMA]+ ILs was introduced to the extraction field for the first time.•Self-assembly extraction was developed by expansion of inevitable third phase.•Self-assembly extraction of Th(IV) exhibited excellent DTh values and selectivity.