A contrast variation small-angle scattering study of the microstructure of 2,5-dimethyl -7- hydroxyl -2, 5-diazaheptadecane-toluene-butanol oil-in-water metallomicroemulsions.

Metallosurfactants comprising copper(ii) (Cu(NO3)2) and zinc(ii) (Zn(NO3)2) nitrate complexes of 2,5-dimethyl-7-hydroxy-2,5-diazaheptadecane were found to form stable oil-in-water microemulsions - metallomicroemulsions - that could solubilise toluene in the presence of butanol. A detailed contrast-variation scattering analysis, employing both neutrons and X-rays, in conjunction with pulsed-gradient spin-echo NMR and simple phase diagram construction, demonstrated that the system formed is that of a conventional microemulsion - a core comprising toluene, separated from the aqueous phase by the surfactant and co-surfactant/co-solvent. This study further demonstrates the versatility of metallosurfactants and the similarity of their physical chemistry behaviour to that of conventional surfactants.