Description
TitleInterfacial molarities in ionic surfactant aggregates
Date Created2016
Other Date2016-10 (degree)
Extent1 online resource (xxii, 160 p. : ill.)
DescriptionThe striking effects of a variety of salts on protein solubility and stability was first discovered by Franz Hofmeister in 1888. For more than a century, ion-specific effects on the properties of ionic colloids, biomembranes and proteins in solution have been demonstrated thousands of times, and the ion-specific order is often called the Hofmeister series. However, a molecular level explanation for ion-specific effects has not been elucidated. Here we are trying to characterize the ion-specific effects at the molecular level by using the chemical trapping method developed by our group. The method is based on the reaction between two specifically designed probes 4-alkyl-2,6-dimethylarenediazonium ion, z-ArN2BF4 (z=16, hexadecyl, z=1, methyl), and weakly basic nucleophiles, such as water, halides, and alcohols in the interfacial region of micelles and other association colloids. This method provides estimates of interfacial molarities of water, counterions for cationic surfactants, and headgroups for anionic surfactants. Our results supports that the ion specific effects in ionic surfactant aggregates depend on a delicate balance-of-forces controlled by ion-pairing, and that hydration interactions within the interfacial region, can be explained by the shift of the interfacial ion-pair/hydration equilibrium. Chapter 1 is a general introduction on pertinent background information including surfactants and their aggregates, ion specific effects, and the logic of chemical trapping method. Chapter 2 describes the characterization the ion specific effects of acetate (AcO-), mesylate (MsO-), chloride (Cl-), bromide (Br-), and iodide (I-) on micelles composed of the twin tail gemini surfactants 1,2-ethanebis(dimethyldecylammonium) (10-2-10 2X) by both the chemical trapping method and MD simulations. In chapter 3, the chemical trapping method is applied to estimate the interfacial water and counterion molarities in 10-2-10 2X (X = MsO, Cl, and Br) gemini surfactant solutions in the presence of added counterion salts NaX (X = MsO, Cl, and Br, respectively). Chapter 4 shows the specific anion effects in micelle-to-vesicle transitions in AOT/salt solutions are determined by the shift in the interfacial ion-pair/hydration equilibrium.
NotePh.D.
NoteIncludes bibliographical references
Noteby Changyao Liu
Genretheses, ETD doctoral
Languageeng
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.