Physico-chemical investigation of nanostructures in liquid phases: Nickel chloride ionic clusters confined in sodium bis(2-ethylhexyl) sulfosuccinate reverse micelles.

The confinement of finite amounts of nickel chloride in the hydrophilic core of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles dispersed in n-heptane has been investigated by FT-IR, UV–vis-NIR and fluorescence spectroscopies. The analysis of experimental data consistently leads to hypothesize that NiCl2 forms small size ionic clusters stabilized by a monolayer of oriented surfactant molecules. Due to confinement and interfacial effects, these ionic clusters show peculiar photophysical properties, which are different from those possessed by the bulk material. From NiCl2/AOT/n-heptane solutions, by evaporation of the organic solvent, interesting salt/surfactant nanocomposites at various salt concentrations have been prepared and characterised by WAXS. On the other hand, after mix with Na2S-containing dry micellar systems, the formation of NiS nanoparticles have been ascertained by UV–vis spectroscopy.