Small-angle neutron scattering will investigate in phase diagrams from binary mixtures of different chain lengths of 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imides ([R-MIM][Tf2N]). Previous work with mixtures of the 1-ethyl and 1-dodecyl derivatives (Sans2d) showed organisation of the long-chain material in the shorter one. This study extends the work to examine self-organisation in different combinations of chain lengths. First experiments will look at the organisation of [C12MIM][Tf2N] in [Cn-MIM][Tf2N] (n = 4, 6, 8, 10) and of [Cn-MIM][Tf2N] in [EMIM][Tf2N] (n = 4, 6, 8, 10): results will allow inform the design of a second series of experiments that will look at different binary combinations. One of the ionic liquids will be used in perdeuterated form to generate usable contrast.