Characteristics of Mixed Reverse Micelles from Ternary Surfactant with Di(2-Ethylhexyl) Tails.

Abstract

To design a novel reverse micellar system for protein extraction, binary and ternary reverse micellar systems composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT), di(2-ethylhexyl)phosphoric acid (DEHPA) and di(2-ethylhexyl) phosphorothioic acid (DEPTA) in isooctane are examined for the water solubilization and the extraction characteristics of proteins. The AOT-DEHPA-DEPTA ternary surfactant system is found to be suitable for protein extraction. The size of the mixed reverse micelle was determined by the small angle X-ray scattering method. It appears that both the water content and the micelle size for the ternary system are larger than those for the AOT and DEPTA single systems. Hemoglobin was successfully extracted by the ternary system, and back-extraction can be realized by use of a weaker alkaline solution (pH 9.5) with the addition of a small amount of n-octanol in the organic phase.