pH and surface tension dependence of mixed sodium deoxycholate-dehydrocholate pre-micellar aggregation in aqueous solution

MARCOS D. FERNANDEZ LEYES; PAULA V. MESSINA; PABLO C. SCHULZ

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS

Elsevier

Lugar: Amsterdam; Año: 2008 vol. 329 p. 24 - 30

0927-7757

The behavior of the sodium dehydrocholate (NaDHC)-sodium deoxycholate (NaDC) mixed system was studied by a battery of methods that examine effects caused by the different components of the system: monomers, micelles, and both components. The behavior of the mixed micellar system was studied by the application of Rubingh´s model. The obtained results show that micellar interaction was repulsive when the aggregates were rich in NaDHC. The gradual inclusion of NaDC in micelles led to a structural transformation in the aggregates and the interaction became attractive. The bile salts´ behavior in mixed monolayers at the air-solution interface was also investigated. Mixed monolayers are monotonically rich in NaDC, giving a stable and compact adsorbed layer. Results have shown that the interaction in both micelles and monolayer is not ideal and such behavior is assumed to be due to a structural factor in their hydrocarbon backbone