摘要
Microemulsions of both O/W and W/O types were formulated by using Brij76, Brij97 and Tween80 as nonionic surfactant and propanol or butanol as cosurfactant with isopropyl myristate oil and water. Low concentrations of sodium salts of hexanoic, decanoic, palmitic and stearic acids were added to the prepared microemulsions to assess their ability to enhance microemulsion stability. Solubilization capacity of microemulsions was estimated and compared with their conductivities at the same water content. Solubilization capacity for YweenS0-containing microemulsions was found to be lower than that of Brij containing microemulsions. Different effects of the ionic surfactants at the maximum solubilization capacity were observed in both O/W and W/O microemulsions. Microemulsion conductivity results showed that different ionic surfactants exerted minor and comparable effects regardless to the implemented nonionic surfactant. Analysis of solubilization conductivity revealed that the presence of ionic surfactant can improve microemulsion solubilization capacity and provided that optimum physicochemical properties for both surfactants are fulfilled. These properties have direct impact at the goodness of the interracial film.