Yingge Du

Understanding topotactic phase transitions in epitaxial oxide thin films

Yingge Du
Physical Sciences Division, Pacific Northwest National Laboratory

Thursday, Sept. 26
4-4:50 p.m.
Johnson 102

 

Abstract

Structurally ordered oxides exhibit a broad range of structural, compositional, and functional properties, which can be further tuned by means of judicious elemental doping, strain and defect engineering. As such, they have found widespread application in energy storage and conversion devices, particularly for use as electrocatalysts, cathodes, and solid state ionics. However, as-designed materials can undergo dramatic changes due to ion diffusion, which, in many cases, leads to performance degradation and device failure.

This talk will highlight our most recent effort aiming to modify complex oxides through heteroepitaxy to achieve tunable functional properties. Combining in situ and environmental transmission electron microscopy (TEM), 18O2 labeled time-of-flight secondary ion mass spectrometry (ToF-SIMS), and ab initio simulations, we elucidate the structural and chemical evolution pathways in selected materials systems and reveal how such changes impact their functional properties. The first part of my talk focuses on Brownmillerite (BM)-structured SrFeO2.5 (BM-SFO), and rhombohedral-structured SrCrO2.8 (R-SCrO), which are perovskite (ABO3)-associated structures that contain ordered oxygen vacancy channels. We show that at relatively low temperatures, a topotactic phase transition between BM-SFO (R-SCrO) and perovskite SrFeO3 (SrCrO3) can be promoted, delayed, or prohibited based on the interfacial strain conditions, highlighting the importance of interface engineering in designing robust and efficient ion conducting materials. In another example, I will present the epitaxial growth and in situ TEM studies of LiCoO2 with or without overlayers to understand the Li transport processes and device failure mechanisms. In both cases, the high spatial and temporal resolution offered by advanced electron microscopy allows the visualization of reaction onset, kinetics, intermediates, and final products, which is critical for the rational design of functional materials.

 

About Dr. Du

Dr. Yingge Du is a senior staff scientist in the Materials Group of the Physical and Computational Sciences Directorate. Upon receiving his PhD from the University of Virginia, he joined PNNL in 2007 and became a staff member in 2010. He served as technical lead in the acquisition and commissioning of a new state-of-the-art oxide molecular beam epitaxy (MBE) system for the EMSL user facility located at PNNL. His current research focuses on growth and characterization of epitaxial metal oxide films and superlattices for energy conversion and storage applications.

Dr. Du is the recipient of a 2016 DOE Early Career Award, which supports him to conduct basic research that aims to understand, predict, and ultimately control cation/anion ordering and topotactic phase transitions occurring in transition metal oxide thin films. Achieving so will enable energy materials (e.g., catalysts, electrodes, and electrolytes) with desired functionalities to be designed, synthesized, stabilized, and harnessed for technological benefits.

 

Identifying Active Surface Entities for Catalytic Conversion by Multimodal Surface X-ray Probes

Hua Zhou 
Advanced Photon Source, Argonne National Laboratory  
 
Monday, Sept. 30 
4-4:50 p.m. 
Johnson Hall 102 
 

Abstract

Electrocatalysts are materials designed to provide a facilitating environment for electrochemical conversion and synthesis of materials and fuels from atmospheric molecules, which is one of the most important challenges facing societal need of energy in 21st century. One of the major hurdles developing electrocatalysts is the lack of holistic information of the evolving surface structure of materials during electrochemical operation. This is particularly formidable for oxygen evolution reaction (OER), where the oxidizing environment is corrosive and can significantly rearrange the electrocatalyst surface structure. Surface-sensitive X-ray probes from modern synchrotron sources including surface X-ray scattering and grazing incidence X-ray spectroscopy provide a very powerful suite of toolkits to decipher the surface subtlety and evolution. If utilizing these techniques in a well-coordinated approach, one can deliver thorough and deep fundamental insights of surface transformations (e.g. structural, chemical and electronic) during the electrocatalytic process.

In this talk, we will firstly render a brief survey of various surface sensitive X-ray techniques to specifically probe structural and chemical aspects of electrocatalytic materials, in particular the combined approach to differentiate the contribution from surface and bulk layers. Following the survey, we would like to present a few prototypic studies of model systems (e.g. functionalized graphene and metal oxides) for surface catalytic processes. First example is the detailed understanding of the noncovalent functionalization of graphene by small molecule aromatic adsorbates (e.g. phenanthrenequinone), which demonstrates persistent redox activity associated with proton‐coupled‐electron‐transfer reactions. Surface X-ray scattering analysis integrated with ab-initio calculations reveals how the prior introduction of defects and oxygen functionality (hydroxyl and epoxide groups) to the graphene basal plane effectively stabilizes its noncovalent functionalization. The second major demonstration is to present a comprehensive study of the emergent surface transformation of SrIrO3, the most active OER electrocatalyst reported to date, especially the amorphous boundary layer that forms from the pristine crystalline structure on the surface with OER cycling. In virtue of multimodal X-ray probing, a step-by-step transformation mechanism of the amorphization process could be explicitly illuminated. Our X-ray results show that the amorphization is triggered by the lattice oxygen activation and the structural reorganization facilitating coupled cation and anion diffusions is key to the realization of the OER active structure in the final SryIrOx form which exhibits stronger disorder than conventional amorphous IrOx, explaining its champion OER activity. In the end, I will give a short commentary on future opportunities in X-ray studies of multifunctional surfaces and interfaces for energy conversions enabled by the exciting advancements towards ultimate storage rings, in particular with enhanced high-energy and coherence capabilities.

 

About Dr. Zhou 

Dr. Hua Zhou is a staff physicist at the Advanced Photon Source (APS) in Argonne National Laboratory. He has managed and developed scientific programs dedicated for in-situ/operando and real-time X-ray studies of advanced materials synthesis, functionality and applications, in particular on surface/interface phenomena and processes in complex environments (e.g. thin film deposition of epitaxial nanostructures and heterostructures, emergent physics of strongly correlated condensed matters, versatile solid/liquid/gas interfaces for electrochemical energy storage and conversion systems) at the APS since 2011. He has extensive research experience using synchrotron-based X-ray techniques to characterize and uncover surface/interface structural modifications and dynamics of epitaxial thin films and heterostructures by using phase retrieval direct methods. Before he joined the APS, he was a postdoctoral fellow in National Synchrotron Light Source at Brookhaven National Laboratory and in Chemical Science and Engineering Division at Argonne National Laboratory. He received his Ph.D. degree in Materials Science from University of Vermont in late 2007. His work and contributions on thin films/heterostructures and surface/interface X-ray scattering techniques have been featured in book chapters, reviewers and more than 120 peer-reviewed publications. He has presented about more than 30 invited speeches in international conferences, universities and national labs.

Development of Alternative Water Supplies: Innovative Technologies for Water Reuse and Desalination

Pei Xu 
Department of Civil Engineering, New Mexico State University
 
Monday, Oct. 7
4-4:50 p.m. 
Johnson Hall 102 

 

Abstract

Water scarcity and the need to meet the increasing water demands have driven the development of alternative water supplies including seawater, brackish water, agricultural, municipal and industrial wastewaters. Given the energy intensity of existing water infrastructures, it is critical to develop sustainable paradigms for water and wastewater engineering that will balance energy consumption, economic benefits, ecological impacts, and social acceptance. This presentation will highlight a number of innovative technologies for improving process efficiency, reducing carbon footprint, recovering resources from wastewater, generating water with quality tailored for various uses, and an integrated decision support tool for produced water treatment and reuse.

 

About Dr. Xu

Dr. Pei Xu is a professor in the Department of Civil Engineering at the New Mexico State University. She teaches courses in introduction to environmental engineering, physical/chemical/biological treatment processes, environmental engineering field session, advanced water treatment and reuse, sustainability in food-water-energy-environmental systems, and capstone design projects. Pei's research focuses on water reuse, desalination, and concentrate treatment for inland applications. The goal of her research is to address critical water shortage challenges in arid and semi-arid regions. Her work has been funded by NSF, DOE, BoR, USGS, Water Research Foundation, NASA, and water industry. She currently is a member and co-lead of the Engineering Thrust of the NSF Engineering Research Center for Re-Inventing the Nation's Urban Water Infrastructure (ReNUWIt). She was recently selected as the AAAS Leshner Fellow on Food and Water Security, PESCO Endowed Professorship and C. Herb Ward Family Endowed Interdisciplinary Chair at NMSU.

William Prusinski

Biocompatible and Bioactive Surface Coatings for Selective Interactions in Complex Media

William Prusinski
Doctoral Student in Chemical Engineering 

Monday, Oct. 14
4-4:50 p.m.
Johnson 102

 

ABSTRACT

Surfaces that contact blood must often be biocompatible to resist fouling via protein adsorption while simultaneously presenting biological activity. We will describe our work toward a universal nanocoating platform created by attaching biomolecules to a hyperbranched pendent hydrophilic polymer brush. This approach integrates a generic priming layer with in situ surface-initiated atom-transfer radical polymerization (SI-ATRP). Enzymes with desirable activity are then immobilized using highly specific click chemistry with non-canonical amino acids, which are incorporated into the peptide sequence at precisely controlled locations through genetic code expansion (GCE) techniques. The brush layer generally retains its protein-repulsive properties after the immobilization. This selectively fouling technology is expected to decrease the cost of bioactive coatings by providing a unified method for coating of various materials, and by eliminating expensive pre-purification steps required by conventional conjugation methods. These coatings may provide a safer and less expensive surface for bioprocessing, biomedical devices, biosensors, and other applications where resistance to protein adsorption must be coupled with biological activity.

 

ABOUT WILLIAM PRUSINSKI

William Prusinski is a third-year doctoral student majoring in chemical engineering at Oregon State University. He works in the Biomaterials and Biointerfaces Laboratory with mentorship from Profesor Kate Schilke, where he researches biocompatible and bioactive surface coatings comprised of enzymes immobilized on hydrophilic polymer layers. He studies the interactions between these coatings and proteins in complex media. The goal of this research concerns improving the antifouling properties of materials for biomedical device applications. Prior to studying at Oregon State, Will earned a Bachelor of Science in Biochemistry from Valparaiso University in 2016 and then interned in the Office of Energy Policy and Systems Analysis at the U.S. Department of Energy in Washington, D.C.

Alyssa Saito

Chlorinated Ethene Degradation by Pseudomonas mendocina KR1 Grown on Various Substrates: Pure Culture and Co-encapsulated with Slow Release Compounds

Alyssa Saito
Master's Student in Environmental Engineering 

Monday, Oct. 21
4-4:50 p.m.
Johnson 102

 

ABSTRACT

Half of the population of the United States relies on groundwater for domestic uses, and yet many of the aquifers across the nation contain low levels of contamination of volatile organic compounds (VOCs). A class of VOCs that are common and hazardous contaminants are chlorinated solvents such as trichloroethylene (TCE), cis-dichloroethene (cis-DCE), 1,1-dichloroethene (1,1-DCE) and vinyl chloride (VC). One method of treatment is through bioremediation by microbes capable of aerobic cometabolism; the induction of oxygenase enzymes in microorganisms growing on a primary substrate that fortuitously degrades contaminants. Pseudomonas mendocina KR1 is a toluene-utilizing bacteria that can cometabolically transform chlorinated ethenes through the activity of the toluene-oxidizing enzyme, toluene-4-monooxygenase (T4MO). This research investigated both the level of induction of the T4MO in KR1 grown on various growth substrates, as well as the novel development of co-encapsulating KR1 with a slow release compound (SRC) in gellan gum for long-term transformation of contaminants. The level of T4MO expression was evaluated by two methods: 1) Activity based labeling (ABL); a gel assay method used to identify catalytically active monooxygenases (e.g. T4MO), and 2) resting cell kinetic tests in which a known mass of cells grown on a primary substrate are exposed to a contaminant of interest and initial rates of degradation and transformation capacities are determined. Potential SRCs were co-encapsulated with KR1 in gellan gum macro-beads and evaluated through kinetic tests in batch systems over time.

 

ABOUT ALYSSA SAITO

An Oregon native from the Gorge area, Alyssa came to Oregon State University to obtain her Bachelor of Science in Environmental Engineering. Wanting to continue her education, she stayed to pursue her master's in the same field. Her interest in how microbial processes could be utilized for remediation led her to join Lewis Semprini’s research lab, which focuses on the bioremediation of chlorinated solvents in groundwater and soil. Alyssa’s research has focused on developing a novel immobilized system for in situ treatment of chlorinated ethenes.

Owen McCarty

The blood microenvironment: The good, the bad, and the sticky

Owen McCarty
Department of Biomedical Engineering, Oregon Health & Science University

Monday, Oct. 28
4-4:50 p.m.
Johnson 102

 

Abstract

Hemostatic plug formation upon blood vessel breach is initiated by platelet recruitment, activation and aggregation in concert with thrombin generation and fibrin formation. However, a similar process can also lead to pathological processes including deep vein thrombosis, ischemic stroke, or myocardial infarction, among others. We have developed narrow mechanism-specific agents targeting the intrinsic pathway of coagulation and demonstrated that experimental thrombosis and platelet production in primates is interrupted by selective inhibition of activation of coagulation factor (F)XI by FXIIa. In this seminar, I will present new data on the role of the endothelium in inactivating FXI, as well as studies on whether inhibiting FXI is beneficial in a non-human primate model of sepsis. I will present our first data from our clinical trial on the safety of inhibition of FXI, and plans to test the efficacy of FXI inhibition in dialysis. The understanding of the mechanisms by which the intrinsic pathway of coagulation promotes thrombus formation may support the rationale for the development of selective, safe and effective antithrombotic strategies targeting FXI.

 

About Dr. McCarty

A native of Rochester, Dr. McCarty received his bachelor of science in chemical engineering from SUNY Buffalo, and a doctorate in chemical engineering from Johns Hopkins University, where his research focused on the identification and characterization of tumor cell receptors for blood platelets and leukocytes. He performed his postdoctoral research on platelet cell biology in the Pharmacology Department at the University of Oxford and University of Birmingham, UK, in the group of Dr. Steve Watson. McCarty joined Oregon Health & Science University in 2005, where he holds an appointment as a professor in the departments of Biomedical Engineering and Cell, Developmental & Cancer Biology and in the Division of Hematology & Medical Oncology in the OHSU School of Medicine. McCarty serves as chair of the Biomedical Engineering Department and a fellow of the American Heart Association.

Richard Oleksak

High temperature corrosion of structural alloys in CO2

Richard Oleksak ('15 Ph.D., Chemical Engineering)
Contracting Research Scientist, National Energy Technology Laboratory

Monday, Nov. 4
4-4:50 p.m.
Johnson 102

 

Abstract

Supercritical CO2 (sCO2) power cycles represent a potentially transformative technology for electricity production in the fossil, nuclear, and concentrated solar industries. A primary barrier to the realization of this technology is identification of structural alloys that can withstand exposure to these harsh environments for the very long operating lifetimes of the plant (> 20 years). This presentation provides an overview of research at NETL aimed at understanding the high temperature oxidation (corrosion) behavior of candidate steels and Ni-based superalloys in the environments expected in future sCO2 power cycles. Both in situ and post-exposure characterization methods have been used to gain insights into alloy corrosion processes at times ranging from the very initial stages of oxidation, to more than one year of exposure. The goal of this work is to achieve a fundamental understanding of degradation mechanisms that can ultimately limit the useful life of a structural alloy component in an sCO2 power cycle.

 

About Dr. Oleksak

Richard Oleksak is a contracting research scientist working with the Structural Materials Team at the National Energy Technology Laboratory in Albany, Oregon. He received his doctorate in chemical engineering from Oregon State University in 2015. His current research focuses on understanding the oxidation and corrosion behavior of structural alloys in next-generation power systems.

 

The Quest to Unlock the Mysteries of Biological Phosphorus Removal

Adrienne Menniti
Clean Water Services

Thursday, Nov. 7
5-6 p.m. 
Johnson 102

 

Abstract

Clean Water Services is a resource recovery utility serving approximately 600,000 residents of Washington County, Oregon. CWS was one of the first utilities in the country to receive a stringent effluent phosphorus limit and has spent decades learning how to successfully achieve an effluent limit of 0.1 mg/L total phosphorus through a combination of chemical and biological phosphorus removal. Over the last five years, CWS has invested heavily in research to better understand the fundamental mechanisms governing BPR stability. In this presentation, Adrienne Menniti, principal process engineer at Clean Water Services, will provide an overview of CWS as utility, describe how research fits into the CWS mission, and provide an introduction to the BPR research program. Dr. Menniti will also discuss her career path since receiving a Ph.D. in environmental engineering from the University of Illinois at Urbana-Champaign and review job roles and opportunities for environmental professionals with post graduate degrees in the CWS organization.

 

About Dr. Menniti

Adrienne Menniti is principal process engineer at Clean Water Services, where she has worked since 2013. Prior to CWS, Dr. Menniti was a process engineer at C2HM Hill. Specializing in wastewater process design, Menniti earned both her master's and doctorate in environmental engineering from University of Illinois at Urbana-Champaign in 2008 and a bachelor of science in civil/environmental engineering from the University of Cincinnati in 2001. 

 

Everything is Just Chemistry: One ChE’s Career Journey at a DOE National Laboratory

Graham Parker ('73 B.S., Chemical Engineering) 
Emeritus Senior Staff Engineer, Pacific Northwest National Laboratory

Monday, Nov. 18
4-4:50 p.m.
Johnson 102

 

Abstract

This presentation will highlight a nearly 45 year career of Mr. Parker as a Chemical Engineer at the Pacific Northwest National Laboratory in Richland, Washington. The career path was not always as expected or planed, but was always challenging and satisfying at a laboratory that was dedicated to “Science in the Service of Mankind”. Mr. Parker’s research portfolio includes: water efficiency and wastewater management; atmospheric sciences/air emissions; aerosol physics; nuclear fuel reprocessing; environmental impact statements; indoor air quality; energy end-use metering; building efficiency; coal-to-liquids conversion; energy technology demonstration and deployment; equipment and appliances conservation standards development; and policy development. He will touch upon the education foundation at OSU that enabled him to pursue these research areas and the impacts of his research.

 

About Graham Parker

Graham Parker is emeritus staff at the Department of Energy’s Pacific Northwest National Laboratory. In nearly 45 years at PNNL, he focused on the design, conduct, and analysis of the evaluations of the performance of buildings and equipment. He has worked with domestic and international clients to develop and promulgate energy policies, improve building energy and water efficiency and deploy new and emerging technologies. Parker is a 1973 chemical engineering graduate of Oregon State University. He is a fellow in the Association of Energy Engineers and a member of the AEE Hall of Fame. He is a certified energy manager and certified energy auditor. He is a member of the Asia Pacific Economic Cooperation Expert Working Group on Energy Efficiency, serves on the Northwest Power and Conservation Council’s Regional Technical Forum, and is a member of the city of Richland's Utility Advisory Committee. He is the 2017 recipient of the Tom Eckman Lifetime Achievement Award for Energy Efficiency.

Nanomaterials-enabled biosensing

Larry Cheng
School of Electrical Engineering and Computer Science

Monday, Nov. 25
4-4:50 p.m. 
Johnson 102

 

Abstract

Physics at the nanometer scale can be vastly different from that of bulk materials.  At the nanoscale, electrokinetics of ionic electrolyte, mass transport phenomenon in solutions, and light-wave interactions may not always behave in the ways we expect. In this talk, I will give an overview of my research on nanofluidics, nanoporous materials, nanoparticles, and nanophotonics, in which we take advantage of their unique physical properties at the nanoscale to improve the performance of biosensing and other applications.

 

About Dr. Cheng

Larry Cheng is an associate professor of electrical engineering and computer science at Oregon State University. His research interests are in the development of functional materials and miniaturized devices for biosensing, wearable sensors, and point-of-care diagnostics. His current research also deals with the electrical and optical properties of nanomaterials with the focus on devices for lighting and THz applications. He received his doctorate in electrical engineering from the University of Michigan, Ann Arbor, in 2008. Before joining Oregon State in 2013, he was a research assistant professor in the Department of Chemical Engineering and Advanced Diagnostics and Therapeutics Initiative at the University of Notre Dame, working on nanobiosensors and microfluidic technologies.