Physicochemical Studies on the Interfacial and Bulk Behaviors of Sodium N-Dodecanoyl Sarcosinate (SDDS)

摘要

Sodium N-dodecanoyl sarcosinate (SDDS), a novel amino-acid based surfactant, has immense biological and industrial importance. Although it is being used in a number of cosmetic formulations, systematic analysis of the bulk and interfacial properties of the surfactant is scarce in the literature. In this study, effects of salt, temperature, and pH on the self-association and related properties of SDDS have been examined in detail using methods such as tensiometry, conductometry, fluorimetry, pH-metry, spectrophotometry, calorimetry, and circular dichroism. The nature of amphiphilic packing and the aggregation numbers of the assemblies have been deciphered. Properties of the acid form of the surfactant have also been explored. The results have been conceptually rationalized and systematically presented together with associated energetics of the interfacial adsorption and self-aggregation of the surfactant in the bulk.