X-ray spectroscopy and scattering study on aqueous solutions of small organic molecules
Abstract/Contents
- Abstract
- Water interacts with molecules through many different ways. Polarity of the solute molecule plays a very important role in inter-molecular interactions in aqueous solutions of organic molecules. Techniques of X-ray spectroscopy and scattering have been developed since last decade to investigate the hydrogen bond (H-bond) structures in liquid water and solutions. This thesis summarizes the results of studies by those techniques on interactions between water and apolar (hydrophobic effects) or polar groups (dipole interaction and H-bond ) of small organic molecules. Size dependence of hydrophobic effects were studied in amphiphilic (CnH2n+1)4NBr solutions as the size of cations grows with n increasing from 1 to 4. Oxygen K-edge X-ray absorption measuring the H-bond structure of water in 1 molality amphiphilic solutions shows crossover of hydrophobic hydration by relating the change in the Hbond structure to a corresponding temperature change and small angle x-ray scattering demonstrates the crossover of hydrophobic interaction by associating diffraction peaks to cation contact pairs. The difference in the temperature effects on interaction between cations further strengthens the hypothesis of the crossover of hydrophobic effects in the solution by XAS and SAXS at room temperature. The aqueous solution of MeCN is explored to demonstrate how water interacts with polar solutes. Both hydrogen bond and dipole interaction between the two species are present in the solution resulting micro-heterogenity or density fluctuation as confirmed by small angle X-ray scattering. However, it is found that dipole interaction between water and MeCN is dominant at interface by oxygen K-edge X-ray absorption in combination with density functional theory calculations, which show changes due to interfacial water directly interacting with MeCN.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2011 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Huang, Ningdong |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Doniach, S |
| Primary advisor | Nilsson, Anders, 1956- |
| Thesis advisor | Doniach, S |
| Thesis advisor | Nilsson, Anders, 1956- |
| Thesis advisor | Lindenberg, Aaron Michael |
| Advisor | Lindenberg, Aaron Michael |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Huang Ningdong. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2011. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2011 by Huang Ningdong
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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