Physical properties of dicarboxylated amino acid based surfactants in presence of diamine alkane counterions

Surfactants are being examined for many different fields such as chemical, medical, cosmetics, and phar- maceutical applications. Surfactants consist of two regions a hydrophobic and a hydrophilic region. The hydrophobic region is the head in most surfactants, while the hydrophilic region is the tail. Surfactants are dynamic molecules and able to form micelles. The micelles form when the hydrophobic region aggregates together and forms different shapes. The concentration at which micelles are formed is called the critical micelle concentration (CMC). The CMC is the lowest concentration needed for the surfactants to form mi- celles. Many different types of surfactants can be created. The surfactants that were examined consisted of dicarboxylated amino acid groups (glutamic and aspartic) with a 11 and 13 caron chain hydrophobic tails. The CMC of these surfactants were measured in presence of 1,2 diamino ethyl, 1,3 diaminopropane, 1,4 diaminobutane, 1,5 diaminopentane and 1.6 diaminohexane. The effects of the different amino acids, tail structures, and counterions were tested by comparing the CMC values of the solution. The CMC was measured using the change in solution conductivity at different surfactant concentrations. Preliminary re- sults indicated that the hydrophobic chain length and the counterion type significantly effects aggregation behavior of the dicarboxylated amino acid surfactants in solution.