| Abstract: | AgCl and AgBr nanoparticles formation conditions were studied by a thermochemical method in AOT (sodium bis(2-ethylhexyl)sulfosuccinate)
inverted micellar systems, in AOT—dioctyl sulfide (DOS) mixed micelles, and (for comparison) in aqueous solutions. The heats
of formation of AgCl and AgBr nanoparticles in AOT micelles in exchange reactions with potassium halides are, respectively,
−55.5 × (1 ± 0.07) and −68.6 × (1 ± 0.07) kJ/mol, that is, smaller in magnitude than the values obtained for aqueous solutions
(−68 × (1 ± 0.07) and −88 × (1 ± 0.07) kJ/mol). This difference arises from the existence of particle interactions causing
the formation of coagulation contacts between halide particles followed by precipitation in an aqueous phase and the absence
of such interactions in a micellar medium. DOS interacts with AOT (to form mixed micelles) and with silver ions (in long-term
contact), thus reducing the heats of reactions. |
