Browsing by Subject "Electrochemistry"
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Item Bi-potential Pulsed Electrochemical Detection of Copper(2017-01-01) Cunning, William Michael; LaCourse, William R; Chemistry & Biochemistry; ChemistryCopper in its pure form is a lustrous red-orange metal that is valued for its electrical, mechanical and aesthetic properties. Aqueous copper is often found in either the +1 or +2 oxidation state, and is used in a variety of applications including: as a dietary supplement, as a biocidal marine paint additive, as an algal and fungal control agent, as an antimicrobial agent, and as the treatment for the protozoan Cryptocaryon irritans (a.k.a. Marine "Ich"). The level of copper in drinking water is strictly monitored by the US EPA, with a maximum contaminant limit of 1.3 parts per million. Literature is replete with analytical methods for the analysis of aqueous copper, with research on this topic dating back centuries. New research seeks to simplify the analysis and broaden matrix compatibility to include beverages and seawater, but reported methods often require extensive sample preparation and preconcentration or, in the case of electrochemical methods, complex chemical electrode modification to achieve the reported sensitivity and selectivity. This research explores the application of bi-potential pulsed electrochemical detection (BPED) to the analysis of copper and other metals after ion chromatography separation. Copper was successfully separated and quantified in the presence of cadmium and lead in fresh water samples. Additionally, copper was quantified in various dietary supplements used to treat copper deficiency in humans. Additional work is presented that shows BPED is capable of being developed into a stand-alone analytical technique for copper at gold and glassy carbon electrodes ? with emphasis on waveform development and optimization techniques. Directions for future work are also explored.Item How Modifying Electrode Shapes Impacts the Fractals Formed During Electrochemical Deposition(2018) Bardzell, Jacob; Casanova, Mason; PhysicsElectrochemical deposition is a process by Electrochemical deposition is a process by which ions migrate to a specific location, solidify, and form clusters. Clusters formed by copper ions during electrochemical deposition can be influenced by the electric field between the electrodes. This electric field can be modified by changing the shape of the outer electrode. The influence of this change can be quantified by determining the relative probabilities that a branch will form towards particular regions. This paper will discuss the impact of the electrode shape on the directional probabilities of individual branches as well as expected cluster growth patterns.Item The Electrochemical Study Of Promethazine HCl In Aqueous Solution At Glassy Carbon Electrode(2012) Tambe Takaw, Robert; Iwunze, Maurice O.; Chemistry; Master of ScienceThe electrochemical oxidation of promethazine hydrochloride (PMT) was studied on glassy carbon electrode (GCE) whose surface area (6.0 x 10 3 cm2) was determined electrochemically. The reference electrode was a commercial calomel electrode and the counter electrode was a wound platinum wire. The electrochemical reaction was conducted at room temperature in a one-electrochemical cell using an electrochemical analyzer supplied by Cypress Systems. The important electrochemical parameters such as the redox potential, Eo, the half-wave potential, E1/2, the diffusion coefficient, D, the number of electrons transferred in the reaction, n, the electron transfer coefficient, &alpha, and the heterogeneous rate constant, ks, were determined in a solution of 4.0 x 10-3 M. These parameters were used in formulating a plausible reaction mechanism of this compound in an aqueous solution. The effect of different surfactants on its stability was also studied. The results of the obtained data indicate that: 1) The electrochemical parameters obtained for this compound were: Eo = 0.60V, E1/2,/super> = 0.67V, D = 3.9 x 10-5 cm2/s, n = 1mole, á = 0.33, ks = 2.45 x 10-4; 2) The peak potential was observed at about 0.60 - 0.80 V and was linearly dependent on the concentration; 3) The observed current intensity which was determined as a function of the voltammetric scan rate, was seen to be linearly related to the square root of the scan rate; 4) The observed peak potential and the peak current were influenced by the pH of the solution; 5) The stability of PMT in different surfactant (cationic, anionic and non-ionic) shows a decrease when compared to the control solution over twenty days. During this period, it was observed that the anionic and the non-ionic surfactants were more effective stabilizers than the cationic surfactants.