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Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.

Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-Liquid Interface

1Department of Chemical and Biomolecular Engineering, University of Notre Dame, 2Department of Aerospace and Mechanical Engineering, University of Notre Dame, 3Department of Chemistry and Biochemistry, Notre Dame Radiation Laboratory, University of Notre Dame

Video Coming Soon

JoVE 56833


 JoVE In-Press

Characterization of Electrode Materials for Lithium Ion and Sodium Ion Batteries Using Synchrotron Radiation Techniques

1Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 2Department of Chemistry, University of Illinois at Chicago, 3Stanford Synchrotron Radiation Lightsource, 4Haldor Topsøe A/S, 5PolyPlus Battery Company

JoVE 50594


 Engineering

Calibration Curves

JoVE 10188

Source: Laboratory of Dr. B. Jill Venton - University of Virginia

Calibration curves are used to understand the instrumental response to an analyte and predict the concentration in an unknown sample. Generally, a set of standard samples are made at various concentrations with a range than includes the unknown of interest and the instrumental response at each concentration is recorded. For more accuracy and to understand the error, the response at each concentration can be repeated so an error bar is obtained. The data are then fit with a function so that unknown concentrations can be predicted. Typically the response is linear, however, a curve can be made with other functions as long as the function is known. The calibration curve can be used to calculate the limit of detection and limit of quantitation. When making solutions for a calibration curve, each solution can be made separately. However, that can take a lot of starting material and be time consuming. Another method for making many different concentrations of a solution is to use serial dilutions. With serial dilutions, a concentrated sample is diluted down in a stepwise manner to make lower concentrations. The next sample is made from the previous dilution, and the dilution factor is often kept constant. The advantage is that only one


 Analytical Chemistry

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

1School of Chemistry, University of Sydney, 2Institute for Superconducting & Electronic Materials, University of Wollongong, 3Australian Synchrotron, 4Australian Nuclear Science and Technology Organisation, 5School of Mechanical, Materials, and Mechatronic Engineering, University of Wollongong, 6School of Chemistry, University of New South Wales

JoVE 52284


 Engineering

Determining the Chemical Composition of Corrosion Inhibitor/Metal Interfaces with XPS: Minimizing Post Immersion Oxidation

1Corrosion and Protection Centre, School of Materials, The University of Manchester, 2Laboratorio de Caracterización de Materiales Sintéticos y Naturales, Instituto Mexicano del Petróleo, 3Departamento de Metalurgia y Materiales, Instituto Politécnico Nacional

JoVE 55163


 Chemistry

Measuring Electrical Conductivity of Living Microbial Biofilms

1Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, 2George Mason University, 3Chemistry Division, Naval Research Laboratory, 4Departments of Physics, Biological Sciences, and Chemistry, University of Southern California, 5Department of Chemical Engineering and Materials Science, Michigan State University

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JoVE 54671


 JoVE In-Press

Internal Standards

JoVE 10225

Source: Laboratory of Dr. B. Jill Venton - University of Virginia

The goal of many chemical analyses is a quantitative analysis, where the amount of a substance in a sample is determined. In order to accurately calculate the concentration of an unknown from a sample, careful sample preparation is key. Every time a sample is handled or transferred, some of the sample can be lost. There are strategies however, for minimizing sample loss. There are also strategies for coping with sample loss and still making accurate measurements of concentration. To minimize sample loss, the ideal is to minimize the number of sample handling and transfer steps. For example, massing a solid sample directly into a flask that a solution will be made in reduces a transfer step. If it's necessary to transfer from one flask to another and a dilution is being made, then triple rinsing the glassware helps ensure all the sample is transferred. Other strategies are more specific to the sample. For example, samples that adsorb to glass, such as proteins, might better be handled in polypropylene disposable tubes. The tubes are not hydrophilic, so if a small amount of sample is to be pipetted in water, it is best to have already added the water to the tube, so the sample can be pipetted directly into the solve


 Analytical Chemistry

Method of Standard Addition

JoVE 10201

Source: Laboratory of Dr. Paul Bower - Purdue University

The method of standard additions is a quantitative analysis method, which is often used when the sample of interest has multiple components that result in matrix effects, where the additional components may either reduce or enhance the analyte absorbance signal. That results in significant errors in the analysis results. Standard additions are commonly used to eliminate matrix effects from a measurement, since it is assumed that the matrix affects all of the solutions equally. Additionally, it is used to correct for the chemical phase separations performed in the extraction process. The method is performed by reading the experimental (in this case fluorescent) intensity of the unknown solution and then by measuring the intensity of the unknown with varying amounts of known standard added. The data are plotted as fluorescence intensity vs. the amount of the standard added (the unknown itself, with no standard added, is plotted ON the y-axis). The least squares line intersects the x-axis at the negative of the concentration of the unknown, as shown in Figure 1. Figure 1

A Method for Systematic Electrochemical and Electrophysiological Evaluation of Neural Recording Electrodes

1School of Psychological Science, La Trobe University, 2Intelligent Polymer Research Institute, University of Wollongong, 3ARC Centre of Excellence for Electromaterials Science, 4Health Innovations Research Institute, College of Science, Engineering, and Health, RMIT University

JoVE 51084


 Neuroscience

Structure Of Ferrocene

JoVE 10347

Source: Tamara M. Powers, Department of Chemistry, Texas A&M University 

In 1951, Kealy and Pauson reported to Nature the synthesis of a new organometallic compound, ferrocene.1 In their original report, Pauson suggested a structure for ferrocene in which the iron is singly bonded (sigma bonds) to one carbon atom of each cyclopentadiene ligand (Figure 1, Structure I).1,2,3 This initial report led to wide-spread interest in the structure of ferrocene, and many leading scientists participated in the structure elucidation of this interesting new molecule. Wilkinson and Woodward were quick to suggest an alternative formulization where the iron is "sandwiched" between two cyclopentadiene ligands, with equal binding to all 10 carbon atoms (Figure 1, Structure II).4 Here, we will synthesize ferrocene and decide, based on experimental data (IR and 1H NMR), which of these structures is observed. In addition, we will study the electrochemistry of ferrocene by collecting a cyclic voltammogram. In the course of this experiment, we introduce the 18-electron rule and discuss valence electron counting for transitio


 Inorganic Chemistry

Proton Exchange Membrane Fuel Cells

JoVE 10022

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University

The United States consumes a large amount of energy – the current rate is around 97.5 quadrillion BTUs annually. The vast majority (90%) of this energy comes from non-renewable fuel sources. This energy is used for electricity (39%), transportation (28%), industry (22%), and residential/commercial use (11%). As the world has a limited supply of these non-renewable sources, the United States (among others) is expanding the use of renewable energy sources to meet future energy needs. One of these sources is hydrogen. Hydrogen is considered a potential renewable fuel source, because it meets many important criteria: it’s available domestically, it has few harmful pollutants, it’s energy efficient, and it’s easy to harness. While hydrogen is the most abundant element in the universe, it is only found in compound form on Earth. For example, it is combined with oxygen in water as H2O. To be useful as a fuel, it needs to be in the form of H2 gas. Therefore, if hydrogen is to be used as a fuel for cars or other electronics, H2 needs to be made first. Thusly, hydrogen is often called an “energy carrier” rather than a “fuel.”

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction

1Department of Chemical and Biomolecular Engineering, North Carolina State University

JoVE 53567


 Chemistry

A Novel Technique for Generating and Observing Chemiluminescence in a Biological Setting

1Department of Radiology, Memorial Sloan Kettering Cancer Center, 2KAUST Catalysis Center, King Abdullah University of Science and Technology, 3Department of Chemistry, Hunter College, and PhD Program in Chemistry, Graduate Center of City University of New York, 4Department of Radiology, Weill Cornell Medical College

JoVE 54694


 Bioengineering

A Protocol for Electrochemical Evaluations and State of Charge Diagnostics of a Symmetric Organic Redox Flow Battery

1Joint Center for Energy Storage Research (JCESR), 2Energy & Environment Directorate, Pacific Northwest National Laboratory, 3Earth & Biological Systems Directorate, Pacific Northwest National Laboratory, 4Physical & Computational Sciences Directorate, Pacific Northwest National Laboratory

JoVE 55171


 Chemistry

Electrochemical Measurements of Supported Catalysts Using a Potentiostat/Galvanostat

JoVE 5698

Source: Laboratory of Dr. Yuriy Román — Massachusetts Institute of Technology

A potentiostat/galvanostat (often referred to as simply a potentiostat) is an instrument that measures current at an applied potential (potentiostatic operation) or measures potential at an applied current (galvanostatic operation) (Figure 1). It is the most commonly used instrument in the electrochemical characterization of anode and cathode materials for fuel cells, electrolyzers, batteries, and supercapacitors. Conventionally, these anode and cathode materials are interfaced with a potentiostat via a three-electrode electrochemical cell. The electrode leads from the potentiostat are connected to the reference electrode, the counter electrode (often called the auxiliary electrode), and the working electrode (which contains the test material of interest). The electrochemical cell is then filled with a high ionic strength electrolyte solution, such as an acidic, alkaline, or salt solution. The media for this high ionic strength solution is typically aqueous; however, for applications necessitating higher operating cell potential windows, such as batteries and supercapacitors, non-aqueous media is often used. The cell media is degassed with an inert gas (to prevent unwanted side react


 Analytical Chemistry

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