Wednesday, June 24, 2009: 11:20 AM
2101/2103/2105 (Marriott Inn and Conference Center University Of MD University College)
Surfactants are amphiphilic molecules containing a long carbon terminated by a polar headgroup. These molecules aggregate together in a spherical structure with a hydrophobic core and an intense surface charge. Water-insoluble molecules can be solubilized in the core and pKa of any acid/base group present is modified. We have employed both of these facts to perform spectrophotometric, thermometric, potentiometric titrations of water insoluble compounds. The results are generally comparable to any traditional titrimetric procedure. It was observed that the pKa values of acids became lower in the cationic surfactant aggregates. We also performed non-linear regression analysis to obtain pKa values from potentiometric titration data. As an extension of this work, we have utilized o/w microemulsions containing oil, water, surfactant and butanol as cosurfactant for such analyses with similar accuracy well. Since surfactants are more benign molecules, their use for analytical determination can play an important role as green solvents.