chemistry

UK Chemistry Alum Bryan Ingoglia Works to Improve Molecular Construction

This article is part of a series of articles on “UK Chemistry Alumni: Where Are They Now?”  Here we feature former undergraduate Bryan Ingoglia who is now is a graduate student in the Department of Chemistry at Massachusetts Institute of Technology. 

Glazer and Heidary Award from the National Science Foundation

The National Science Foundation has awarded a new grant to Drs. David Heidary and Edith Glazer for the development of chemical tools to study RNA. The project, titled “Inorganic-aptamer hybrids for live cell imaging”, leverages the complementary expertise of the investigators in the development of optical cellular assays and the creation of photoactive inorganic molecules.

Developing and Testing Redox Active Organic Molecules for Nonaqueous Redox Flow Battery Applications

Abstract: Non-emissive, sustainable energy sources such as solar, wind, and geothermal power have continued to provide an increasing amount of electricity to support electrical grids. Due to the intermittent nature of renewable energy sources like wind and solar, grid energy storage systems must adjust for variations in and mismatches between electricity production and consumption. Among the available energy storage technologies, redox flow batteries (RFBs) are expected to play a critical role in the grid energy storage due to their decoupled energy and power, long service life, and simple manufacturing. However, the worldwide market penetration of RFB systems is still limited due to technical and economic challenges. The commercially available aqueous vanadium redox flow batteries offer durable performance but suffer from low energy density and high chemical costs. A key advantage of transitioning from aqueous to nonaqueous systems is the possibility of achieving higher energy density through the wider windows of electrochemical stability associated with organic solvents. Further, nonaqueous systems would provide a greater selection of redox materials which do not fit into the aqueous systems due to lower solubility, instability or redox potentials outside the stability window of water. Despite these promises, nonaqueous flow batteries are still an immature concept and, to date, no redox chemistry has proven competitive due to a combination of low solubility and stability of redox couples and a lack of selective membranes/separators. This thesis focuses on designing and testing robust, redox active organic molecules intended for use as either positive or negative active materials in nonaqueous RFBs. The two main redox active cores evaluated in this study are phenothiazine (as a positive active material) and viologen (as a negative active material) where both served as learning platforms. The molecules were functionalized through simple and scalable molecular synthetic approaches with particular emphasis on increasing solubility, ionic conductivity, redox potential, and chemical stability. Further, change in chemical stability of variably functionalized electron donating redox active organic cores (phenothiazine, triphenylamine, carbazole, dialkoxybenzene, and cyclopropenium) with different oxidation potentials was explored to identify the correlation between chemical stability of charged forms (radical cation) and coulombic efficiency in galvanostatic cycling. The analysis of chemical and electrochemical stabilities of developed redox active materials were conducted through a variety of spectro-electro analytical technique including cyclic voltammetry, UV-vis spectroscopy, bulk electrolysis, and flow cell cycling.

Date: 
Friday, September 4, 2020 - 2:00pm to 3:00pm
Location: 
Zoom
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Synthesis of Metal Oxide Surface and Interface Arrays by a Combined Solid-Liquid- Vapor/Vapor-Liquid-Solid Approach

This project was motivated by an in situ heating experiment in the transmission electron
microscope (TEM) in which gold (Au) nanoparticles were observed to dissolve tin dioxide (SnO2)
nanowires (NWs) under vacuum. The explanation for this observation was that the hightemperature
and low-pressure environment of the TEM caused the reverse reaction of the wellknown
vapor-liquid-solid (VLS) method commonly used to grow NWs. In the VLS process, a
metal catalyst absorbs reactant vapor until it becomes supersaturated. The precipitation of the NW
occurs at the liquid-solid interface, which ceases when there is no longer reactant vapor, and the
diameter of the NW is determined by the diameter of the original catalyst. The reverse process, the
solid-liquid-vapor (SLV) method occurs when atoms in a solid NW diffuse into the metal catalyst.
Eventually, the metal catalyst becomes supersaturated and the vapor escapes at the liquid-vapor
interface. In this dissertation we demonstrate the combination of the SLV and the VLS mechanisms
to create embedded heterogeneous interfaces in a variety of metal oxides. Metal catalysts are first
used to etch metal oxide surfaces producing hollow channels that we term “negative nanowires”,
and after etching the metal catalyst is reused to grow a NW of a different material from within the
channel to form a crystalline interface. Understanding the chemical structure at these interfaces is
both crucial and fascinating because diverse materials may interact in a variety of ways, including
atomic mixing of the two structures and/or the formation of an abrupt crystalline interface or gap.
We present our approach, therefore, towards gaining a comprehensive understanding of the
structure-function relationship of these materials, focusing on particular on the interfacial region,
to allow the design of new nanomaterials with tailored functionality.

Date: 
Wednesday, July 15, 2020 - 1:00pm to 2:00pm
Location: 
Zoom

Charles Herschel Holmes Griffith: Laboratory Supervisor & Legend

By J. Susan Griffith, M.D.

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Dr. Sean Parkin Named Section Editor of Acta Crystallographica E

Congratulations to Dr. Sean Parkin, named

Section Editor of Acta Crystallographica E!

Read the full story here.

The Story of a 1949 UK Chemistry Graduate

It was 1949, World War II had ended and twice as many students were enrolled in universities across the country compared to pre-war enrollment, many were on the GI Bill. I was one of those June 1949 GI Bill seniors, graduating from UK with a BS degree in physical chemistry. My name is Alan Veith.

Chemistry Professor Miller Receives Einstein Foundation Award to Support Research in Germany

The Einstein Foundation of Berlin (Germany) has awarded a prestigious three-year fellowship to Prof. Anne-Frances Miller (Department of Chemistry) to support collaborative research to take place in Berlin.  In search of insight as to how new materials and devices can make more versatile and efficient use of energy, Prof. Miller has been studying enzymes from ancient lineages of bacteria.  While on sabbatical two years ago, she initiated high-level computations and spectroscopic studies to complement her biochemical work, funded by the N.S.F.

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