ISBN 9783843920810

978-3-8439-2081-0, Reihe Verfahrenstechnik

Sandra Storm
Molecular Modeling and Experimental Design of Surfactant-Based Extraction Processes

169 Seiten, Dissertation Technische Universität Hamburg-Harburg (2015), Softcover, A5

Zusammenfassung / Abstract

This work focusses on the investigation of micellar extraction processes and the phenomena of micelle formation either in aqueous or in nonpolar organic solutions. These surfactant aggregates facilitate or enhance the extraction of various target compounds, which is important in many industrial and pharmaceutical applications. Therefore experimental techniques and different modeling approaches are combined in this work. By this combination, new insights in surfactant-based processes from the atomic level to the experimental implementation are gained.

In the first part of this work, the reverse micellar extraction of polar biomolecules is investigated via the thermodynamic models COSMO-RS and COSMOmic and experiments. Up to now no predictive models have been used to study the pH-dependent partition behavior in detail, which has been achieved in this work for the first time. Additionally, experiments demonstrated the feasibility of the pH-sensitive selective extraction not only of amino acids and their mixtures, but also of industrial relevant enzyme mixtures from aqueous solutions. In a second part of this thesis, the focus lies on the surfactant aggregation process. In order to understand the mechanism, that take place molecular dynamics simulations (MD) of the surfactant self-assembly in aqueous phases are performed for pure and mixed surfactants. Subsequently, micelles formed by MD, were combined with the model COSMOmic, an extension of COSMO-RS. As a result, free energy profiles of various target molecules (solutes), solubilized in micelles are obtained. These profiles indicate the location of the solutes, as well as probable energy barriers in the system and the total partition behavior can be quantified in terms of partition coefficients. In terms of mixed surfactant systems also synergistic effects were studied.

Thus, this work gives new insights in the process of different micellar solubilization processes, especially in detail on molecular level. The findings can be applied to improve and develop extraction processes, such as the reverse micellar extraction of biomolecules or drug delivery systems or other industrial areas.