Lauren Tom '10 (Stevensville, Mo.) studied general electrochemistry techniques this summer with Professor of Chemistry Timothy Elgren. Electrochemistry is the study of the relationships between chemical reactions and electrical energy. There are two general types of electrochemical reactions: spontaneous reactions that produce electrical energy and nonspontaneous reactions that consume electrical energy. Both types of reactions always involve a transfer of electrons, and, according to Tom, electrochemistry basically "shows where an electron is added or taken away" during a reaction. Thus, electrochemistry is useful for studying electrically active species and aids in identifying their reduction/oxidation potentials (the tendency of a chemical species to be reduced and gain electrons or to be oxidized and lose electrons).
Tom studied electrochemical reactions using a technique called cyclic voltammetry (CV). In CV, an electric potential (i.e. voltage) is applied to the system under investigation and a reduction-oxidation (redox) reaction takes place. Since redox reactions involve a transfer of electrons between different chemical species, an electric current is produced. Tom measured these currents over a range of potentials, starting at an initial value and increasing the potential up to some pre-defined limiting value called the switching potential. After this point, current is measured as the potential is decreased from the switching potential back to the initial starting value. Since the experiment is effectively reversed, any species formed by oxidation during the first, forward scan are now reduced on the second, reverse scan and vice versa.
The experimental apparatus employed by Tom in her CV experiments consisted of a solution containing the electrically active species participating in the redox reaction and three electrodes, which were used to supply free electrons, allow current movement, and measure the voltage. The data obtained from the CV experiments were recorded by a computer, which then plotted the data in the form of a current versus potential graph. This graph is very useful in characterizing an electrically active system because it provides an estimate of the redox potential, the rate of electron transfer, and the stability of the reduced/oxidized forms of the reactants.
Tom's goal this summer was to understand basic electrochemistry techniques and see how the various electrodes behaved during the reactions. Her investigations will provide the groundwork for further applications. In the future, Tom says Prof. Elgren hopes to use electrochemical techniques to study redox active enzymes encapsulated in sol-gel materials. Since many of the redox active enzymes that Elgren studies can be reduced chemically, controlling electron flow through an electrode will allow them to control the activity of the enzyme.
This is Tom's second summer of research at Hamilton. Last year, she worked with Elgren on a different project. A possible American Studies major, Tom participates in numerous campus activities when not in the lab. She is a member of the ballroom dancing club and the volunteer organization HAVOC. This fall she will also begin her second term as the secretary/treasurer for the Class of 2010.
-- by Nick Berry '09
Tom studied electrochemical reactions using a technique called cyclic voltammetry (CV). In CV, an electric potential (i.e. voltage) is applied to the system under investigation and a reduction-oxidation (redox) reaction takes place. Since redox reactions involve a transfer of electrons between different chemical species, an electric current is produced. Tom measured these currents over a range of potentials, starting at an initial value and increasing the potential up to some pre-defined limiting value called the switching potential. After this point, current is measured as the potential is decreased from the switching potential back to the initial starting value. Since the experiment is effectively reversed, any species formed by oxidation during the first, forward scan are now reduced on the second, reverse scan and vice versa.
The experimental apparatus employed by Tom in her CV experiments consisted of a solution containing the electrically active species participating in the redox reaction and three electrodes, which were used to supply free electrons, allow current movement, and measure the voltage. The data obtained from the CV experiments were recorded by a computer, which then plotted the data in the form of a current versus potential graph. This graph is very useful in characterizing an electrically active system because it provides an estimate of the redox potential, the rate of electron transfer, and the stability of the reduced/oxidized forms of the reactants.
Tom's goal this summer was to understand basic electrochemistry techniques and see how the various electrodes behaved during the reactions. Her investigations will provide the groundwork for further applications. In the future, Tom says Prof. Elgren hopes to use electrochemical techniques to study redox active enzymes encapsulated in sol-gel materials. Since many of the redox active enzymes that Elgren studies can be reduced chemically, controlling electron flow through an electrode will allow them to control the activity of the enzyme.
This is Tom's second summer of research at Hamilton. Last year, she worked with Elgren on a different project. A possible American Studies major, Tom participates in numerous campus activities when not in the lab. She is a member of the ballroom dancing club and the volunteer organization HAVOC. This fall she will also begin her second term as the secretary/treasurer for the Class of 2010.
-- by Nick Berry '09
