Theoretical modeling of micellization and solubilization in ionic surfactant systems

Ionic surfactants constitute a very important class of surfactants, both from an academic as well as from a commercial viewpoint. In most commercial applications involving ionic surfactants, the selection of the surfactant is based on its aqueous bulk solution properties, including its micellization characteristics and its micellar solubilization characteristics (that is, the capacity of the surfactant micelles to encapsulate hydrophobic solutes in their interior, leading to a significant increase in the aqueous solubility of the hydrophobic solutes). Accordingly, the development of comprehensive, predictive, molecularly-based theories that relate the bulk solution properties of an ionic surfactant to its chemical structure should facilitate significantly the rational design, selection, and optimization of commercial surfactant formulations. The first major contribution of this thesis was the development of a molecular-thermodynamic theory of micellization of ionic surfactant-electrolyte systems, which takes into account the possibility that counterions (inorganic or organic, monovalent or multivalent) released by the ionic surfactant polar heads and by any added electrolytes can bind onto the charged micelle surface. By minimizing the free energy of micellization, various micellar solution properties were predicted quantitatively in the context of this theory, including : (i) the degree of binding of each counterion species onto the charged micelle surface, (ii) the micelle surface electrostatic potential, (iii) the critical micelle concentrations (CMC's), and (iv) the optimal shapes and average sizes of the micelles formed in solution.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2003

Author dc:creator

• Srinivasan, Vibha, 1976-

Advisor dc:contributor.advisor

• Daniel Blankschtein.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/29608

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/29608