The Materials Science RPA periodically runs funding competitions across a variety of categories including Seed Grants, Equipment Grants, Vouchers for User Center Access, Conference Grants, Student Support Grants, and Faculty Success. See below for recent awardees listed by category with project abstracts.
FY2024 Materials Science Awards Abstracts
Seed Grants
Single Atom Catalysts on Chalcogenide Supports Through Intense Pulsed Light - Aron Huckaba, Chemistry
Heterogeneous metal catalysts are the most used type of catalyst used industrially. Unfortunately, the metal catalyst particle size distribution and metal catalyst dispersion within the support are difficult to control with current synthesis protocols. One especially important type of reaction is the hydrogen evolution reaction, which will are useful in water electrolyzer devices. To make meaningful improvements to the gold standard material (20% Pt/C), the metal catalyst should be reduced as much as possible while increasing the catalyst loading in the support as much as possible. Accordingly, the ideal catalyst would then be single atom catalysts that could be dispersed inn the support at high catalyst loadings. This project aimed to accomplish both of these goals through the intense pulsed light annealing of Pt (IV) precursors. We studied how varying the mixing method between the Pt precursor, (H)2(PtCl6), and the WS2 support affected the Pt loading and the catalytic performance. Additionally, we synthesized alternative Pt precursors (NH4)2(PtCl6) and (H3CNH3)2(PtCl6). We found that when using the (H)2(PtCl6) precursor, the highest mass activity during the hydrogen evolution reaction was highest for slurry mixed catalysts, followed by dry mortar and pestle mixed, then followed by solution phase mixing. Each of the catalysts outperformed the reference catalyst material, 20% Pt on C.
Addressing the instability issue of Fe-N4-C single atom catalysts for oxygen reduction reaction (Doo Young Kim, Chemistry)
Oxygen reduction reaction (ORR) is a key cathodic reaction that determine the overall efficiency of hydrogen fuel cells. Also ORR is a key half-reaction in electrochemical energy storage (e.g., metal-air batteries). Platinum (Pt) nanoparticles attached to high-surface-area carbon support (Pt/C) are a state-of-the-art cathodic electrode for ORR. However, Pt/C is not suitable for commercial applications because of the expensiveness and scarcity of Pt. Therefore, it is pivotal to develop alternative catalysts that require no or sufficiently less amount of platinum. Fe-N/C single atom catalysts (SACs), where earth-abundant iron (Fe) is atomically dispersed in porous, conductive graphitized carbon network, have shown excellent ORR activity, comparable to or exceeding commercial Pt/C. The coordination of Fe metal center with 4 nitrogen atoms (Fe-N4) enables Fe to have an optimal binding strength for adsorption and desorption of O2 molecules for ORR. Despite its great potential, a gradual decay in the long-term activity of Fe-N/C is a critical hurdle against the large-scale implementation of this catalyst in commercial fuel cells. It was reported that this instability is linked to the demetallation of Fe centers during ORR. The consensus is that Fe demetallation originates from insufficient bond strength between Fe and N ligands. To balance between ORR activity and stability, foundational knowledge of the structure-function-activity relationship of Fe-N/C as well as molecular-level modification of ligands are crucial. This project will (1) investigate ORR mechanistic pathway of Fe-N/C, (2) determine its deactivation mechanism, (3) determine its chemical nature and local microenvironment using various chemical probe and spectroscopic techniques, and (4) perform the molecular-level modification of ligands.
Multifilament spinning of PEDOT:PSS conductive fibers toward electronic textile applications
E. Ashley Morris, Center for Applied Energy Research
Evaluating and eliminating electrode-induced degradation in organic electrochemical transistors
Alexandra Paterson, Chemical & Materials Engineering
Organic electrochemical transistors (OECTs) simultaneously couple ionic and electronic charge transport. While OECT research has made significant advances in recent years, poor stability is the bottleneck impacting all technologies in the enormous OECT application space: From biosensors, medical devices for drug delivery, and adaptive healthcare technologies, to artificial synapses for coupling neurons and controlling prosthetic devices, neuromorphic hardware for advanced computing, and chemical sensing for precision agriculture. A key source of instability is the interface between the metallic electrode and conjugated polymer. This project combines Paterson’s (College of Engineering) OECT device fabrication and characterization with Graham’s (College of Arts and Sciences) electrochemical and photoemission spectroscopies to investigate chemical degradation reactions as a function of the electrode/organic interface in OECTs. The project uses both bare metal electrodes and metal electrodes with self-assembled monolayers (SAMs) to determine the impact of the metal/organic interaction on degradation reactions, while also testing the ability of the SAM to improve OECT stability. Overall, this project aims to enhance OECT stability, while uncovering the fundamental mechanisms thereof.
Nanoporous Materials for Selective Separation and Purification of Phenolic Oligomers from Lignin-First Biomass Processing
Stephen Rankin, Chemical & Materials Engineering
Equipment Grants
Acquisition of a pycnometer
Malgorzata Chwatko, Chemical & Materials Engineering
Gas pycnometer was successfully purchased to provide enhanced capabilities to determine density and porosity of varying materials. The pycnometer has numerous cell sizes to accommodate varying specimen sizes. Samples such as polymers, ceramics, metals are expected to work well as long as enough sample is available. The instrument is available in ASTeCC, please reach out to Gosia Chwatko, m.chwatko@uky.edu for access.
Surface Profiler through the Center for Nanoscale Science and Engineering
Todd Hastings, Electrical and Computer Engineering
The new Bruker Dektak XT surface profiler is now available for use in the Center for Nanoscale Science and Engineering. The profiler quickly measures step heights and surface roughness up to 1 mm high over distances up to 50 mm. The built-in microscope allows alignment to specific features or areas of interest. In addition, the profiler features the 2D stress measurement option for determining thin-film stress and the low force measurement option for accurately characterizing soft samples without damage. The instrument is located in room A368 of the ASTeCC building (central campus, connected to Grehan, McVey, and Raymond). Requests for training and reservations for use may be made through Facility Online Manager (https://uky.fomnetworks.com/fom/) using your linkblue credentials. Please contact Todd Hastings (todd.hastings@uky.edu) with any questions.
New and Enhanced Research Infrastructure: Building SEM In Situ Nanoindentation Capabilities
Paul Rottmann, Chemical & Materials Engineering
The development of advanced materials is crucial for various real-life applications, from aerospace and automotive industries to biomedical implants and electronic devices. Understanding the mechanical properties of these materials at the micro- and nanoscale is essential for optimizing their performance and reliability in different environmental conditions. Our project aims to advance materials science by providing unprecedented insights into the mechanical behavior of Multi-Principal Element Alloy (MPEA) thin films under different treatment conditions, ultimately bridging the gap between nanoscale material behavior and macroscale performance. To achieve this goal, we are utilizing the FemtoTools In-situ SEM/FIB Nanoindenter (FT-NMT04), compatible with the Helios 660 SEM at the University of Kentucky's Electron Microscopy Center. This state-of-the-art system allows for real-time observation of material deformation processes during mechanical testing, providing a comprehensive understanding of the process-structure-property relationships in MPEAs.
The FT-NMT04 nanoindenter enables the quantification of critical mechanical properties such as hardness, elastic modulus, and strain rate sensitivity. With its impressive force range up to 200 mN and low noise floor of 500 nN, the system offers exceptional versatility and precision for our research. The nanoindenter is optimized for testing metals, ceramics, thin films, and micro-scale structures like metamaterials and MEMS. Its modular design with interchangeable tips (Berkovich, flat punch, and dog-bone tensile grip) and ability to apply both monotonic and cyclic loading allow for comprehensive material characterization. Typical applications of this advanced setup include quantifying plastic deformation mechanisms through micro-pillar compression testing, tension testing of dog-bone shaped specimens and thin films, and fracture testing of micro-cantilevers using continuous stiffness measurement (CSM) for J-integral quantification of fracture toughness and crack growth events.
Two 200 mN diamond tip Berkovich force sensing probes for this system were purchased using funds awarded by the m-RPA. The FemtoTools FT-NMT04 system is available for collaborative use. Interested m-RPA members should email Paul Rottmann (paul.rottmann@uky.edu).
