Comparison of Methyl Glucamine and Glycoside Surfactant Headgroup Synergism with Alkyl Sulfates

The study of biosurfactants is important in making many industries more environmentally conscience. One way to encourage use of biosurfactants is to determine which biosurfactants display better synergism with more commonly used surfactants. Linear alkyl sulfates were selected as the commonly used surfactants, and alkyl N-methyl glucamines and alkyl glucopyranosides or glycosides were chosen as the biosurfactants to display synergism. Six pairings were chosen based on similar CMC in order to ensure that observed synergism was based mostly on surfactant interaction (the β parameter). These are S12S-MEGA10, S12S-9GPN, S10S-MEGA9, S10S-8GPN, S9S-MEGA8, and S9S-7GPN. Mixtures of these were made at varying mole fractions and varying concentrations. These solutions were tested and evaluated to determine critical micelle concentration (CMC), surface tension at the CMC, surface tension reduction efficiency, and solubilization power with decane. The results were evaluated and show synergism in both the alkyl sulfate-alkyl methyl glucamine as well as the alkyl sulfate-alkyl glycoside systems. However, a much greater interaction was seen between the sulfate headgroup and the methyl glucamine headgroup.