66 Surfactants In Green Chemistry Part 1: Their Use as Solvents for Titrations of Water Insoluble Compounds

Wednesday, June 24, 2009: 11:20 AM
2101/2103/2105 (Marriott Inn and Conference Center University Of MD University College)
Shyam Shukla , Department of Chemistry and Center for Green Science and Technology, Lamar University, Beaumont, TX
Paul Anastas , Chemical Engineering, Yale University, New Haven, CT
Julie B. Zimmerman , Chemical Engineering Department, Environmental Engineering Program, Yale University, New Haven, CT
S. Bhanumati , Chemistry Department, Reader, New Delhi, India
Mohammad Musaddaq , Department of Chemistry and Center for Green Science and Technology, Lamar University, Beaumont, TX
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. 
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