Interfacial properties between aqueous and organic phases in AOT reversed micellar system for lysozyme extraction

The interfacial tensions of several solutions of reversed micellar systems used in lysozyme extraction were measured by drop weight and pendant drop m ethods. The organic phase was 2,2,4-trimethylpentane containing sodium bis( 2-ethylhexyl)sulfosuccinate (AOT), and the aqueous phase was a solution of lysozyme and KCl, NaCl or CaCl2. The effects of salt concentration and salt type on the interfacial tension were studied. The hydration of cation asso ciated with AOT affects interfacial properties to some extent. At the same ionic strength, the interfacial flexibility decreased with type of salt, Na Cl > CaCl2 > KCl. This order corresponds to that of the cation's hydration number. Overall mass-transfer coefficients of lysozyme were also measured u nder various salt concentrations of three salt systems and were expressed b y a single curve when plotted against interfacial tension.