Hemimicelles and admicelles are well-investigated wonders in modern science; they are surfactant monolayers and surface adsorbed micelles, respectively. Capacitance measurements for monitoring the formation of dodecyl sulfate (DS) surfactant monolayer on positively charged gold substrates (planar gold) and the adsorbance of 2-naphthol onto DS surfactant monolayer were performed. The investigation of the electrical control of DS at various concentrations (4, 6, 16, and 32 mM) below and above the critical micelle concentration (CMC= 8 mM) on gold surfaces for analyte preconcentration, prior to chromatographic analysis, is presented. Charged ionic surfactants, such as DS, drawn to a surface of opposite charge (porous nickel substrates coated with gold) serve as a stationary phase to trap organic analytes. It is believed that these DS assemblies gain stability through surfactant chain–chain interactions. The attachment and the removal of the surfactant are controlled using an electric field. Due to the fact that the surfactantanalyte association is released by electrical control, organic solvents, which are used in conventional solid phase extraction, are not required, making this procedure environmentally friendly. Electrical Impedance Spectroscopy was used to investigate the formation of the DS layer and the preconcentration of 2-naphthol in the presence of an applied electric field. High performance liquid chromatography was used to determine 2- naphthol concentrations. Anthracene and 9-anthracenecarboxylic acid were substituted as additional test molecules as well. Presented are the results of the preconcentration of 2-naphthol, anthracene and 9-anthracenecarboxylic acid using the DS layer with various concentrations of sodium dodecyl sulfate on a gold electrode surface.
| Identifer | oai:union.ndltd.org:WKU/oai:digitalcommons.wku.edu:theses-2730 |
| Date | 01 October 2016 |
| Creators | Al-Karawi, Dheyaa Hussein |
| Publisher | TopSCHOLAR® |
| Source Sets | Western Kentucky University Theses |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Masters Theses & Specialist Projects |
Page generated in 0.0017 seconds