Electrochemical Investigations Of Self-assembled Monolayers Modified Electrode And Liquid/liquid Interface

Studies of Self-Assembled Monolayers and charge (electron and ion) transfer across a liquid/liquid interface (L/L interface) are one of the novel areas in the field of electrochemistry and electroanalytical chemistry. In my dissertation, the progress and historical background of these areas are briefly reviewed. Electrochemical methods such as cyclic voltammetry and stripping voltammetry are used. New materials such as carbon nanotubes, zeolite membrane and ionic liquid are used to investigate modified electrode and liquid / liquid interface. This dissertation consists of three parts, the main results are as follows:L-cysteine and carboxylated multi-walled carbon nanotubes(MWNTs) chemically assembled on gold substrate was employed as working electrode to determinate trace heavy metal ions using Lead ion as an example. As a new method to the determination of trace level heavy metal ions, instead of mercury-free electrode, it demonstrated its high sensitivity, selectivity, stability and practical application for a simple, rapid and economical determination.The modification of the water/1, 2-dichloroethane interface with a new typeβ-zeolitic membrane is studied. As a means of investigating the analytical potential of this interface, the facilitated transfer of various alkali cations have been investigated using voltammetric methods. This work allows the observation of the transfer of extremely hydrophilic ions, due to the size-exclusion of organic ions from the interior of the zeolitic framework. Additionally, volume exclusion effects are shown to affect facilitated ion transfer processes involving alkali metal cations. It is hoped to extend this study to investigate the diffusion of ions within the zeolite pores with electrochemical methods, and to apply these properties to size selective sensors.The aqueous phase containing a redox couple is supported on the surface of Ag/AgCl electrode, then the electrode is inverted and immersed into the ionic liquid along with reference and counter electrode to construct a classical three-electrode system. Charge transfers have been studied using this novel system. This method is a novel approach and is important to extend this field. This work allows the observation of the potential window and the transfer of ferrocene ion in the water / liquid interface. The results showed that instead of classical organic phase support electrolyte, using ionic liquid as organic phase solvents, the conductivity of the organic phase support electrolyte can be enhanced. The impact on the potential window of adding organic phase and the supporting electrolyte can also be avoided. It is hoped that this approach can solve the problems of liquid / liquid interface and have a certain sense in electrochemical studies for the choice of supporting electrolyte solvent.