Electrochemical and spectroscopic studies of novel electroactive nanostructures /
The first objective of this research was to examine the electrochemical behavior of arrays of nanometer-scale electrodes for agreement with existing microelectrode theory. The randomly-dispersed electrodes were prepared by cyanide etching of a Au(111) substrate passivated by a n-hexadecanethiol mon...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
2002.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=726477251&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The first objective of this research was to examine the electrochemical behavior of arrays of nanometer-scale electrodes for agreement with existing microelectrode theory. The randomly-dispersed electrodes were prepared by cyanide etching of a Au(111) substrate passivated by a n-hexadecanethiol monolayer. The electrode arrays were characterized by scanning tunneling microscopy (STM) and electrochemistry to determine if the measured electrode geometries predict the observed electrochemical response. A second objective was to probe for size-selective molecular recognition behavior at the nanoscale electrodes. For this purpose, a series of viologen-functionalized poly(amidoamine) (PAMAM) dendrimers having hydrodynamic radii ranging from 2 to 4 nm were prepared and electrochemically and spectroscopically characterized. It was found that the electrochemical behavior of the viologenated dendrimers at the nanoelectrode arrays was complicated by adsorption effects. Alternate methods for performing the size-based molecular recognition studies which circumvent the adsorption problem are proposed. An additional investigation was performed to probe the structure of metal ion-coordinated bilayers on Au. In this study, a monolayer of 4-mercaptobenzoic acid on Au was linked to an upper-layer of n-hexadecanethiol via a Cu- or Ag-coordinating metal ion. The bilayers were studied by fourier transform infrared-external reflectance spectroscopy (FTIR-ERS), ellipsometry, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). This study demonstrated that the Ag- coordinated bilayer exhibited twice the coverage of metal ion and n-hexadecanethiol as the copper-based bilayer. This bilayer stoichiometry is of interest for applications requiring films possessing a minimal number of defects. |
|---|---|
| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xiv, 172 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 143-171). |