COLLOID-CHEMICAL INTERACTIONS DURING THE PROCESS OF METAL CONCENTRATION BY REVERSE MICELLES OF ETHOXYLATED SURFACTANTS - A GEOMETRICAL APPROACH

The effects of the volume of a solubilized aqueous solution, the type and concentration of a background electrolyte (HCl and NaCl), and the presence of small amounts of chloroform on the radius of reverse micel les of Neonol AF(9)-4 in n-decane are investigated by photon-correlati on spectroscopy. In solubilization of aqueous HCl solutions, the effec tive hydrodynamic radius of micelles reaches a maximum, whose intensit y depends on the HCl concentration. It is shown that when micellar sys tems containing solubilized aqueous solutions are diluted with n-decan e the size of reverse micelles sharply increases. When the same system s are diluted with chloroform, the hydrodynamic radius decreases and t he solubilized aqueous solution is separated out to form the individua l phase. A number of models describing solubilization processes throug h the relation of geometrical parameters of micelles with the solubili zation capacity of micellar solutions is proposed. It is shown that th e most plausible mechanism of solubilization is the coalescence of mic elles with no change in the area per surfactant molecule in the surfac e layer.