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Faculty News | Pages
Jason F. Weaver, Ph.D., the ExxonMobil Gator Alumni Faculty Endowed Professor, received a National Science Foundation (NSF) grant to study selective methane oxidation using elaborately structured IrO2-based mixed metal oxides.
In this project, Dr. Weaver will collaborate with UF ChE researchers Helena Hagelin-Weaver, Ph.D., an associate professor, and David Hibbitts, Ph.D., an assistant professor and holder of the Moreno Rising Star Professorship, to develop a fundamental understanding of the selective conversions of methane to more valuable chemicals using well-defined oxide catalysts.
“Designing catalyst structures with atomic-level precision is an important step toward efficiently and selectively converting methane to chemicals. In our new project we are trying to synthesize catalysts with small amounts of Ir dispersed throughout a less reactive host oxide. Our guiding hypothesis is that atomic scale Ir-O moieties will be able to efficiently break the first C-H bond(s) of CH4 but that the lower reactivity of the host oxide will suppress extensive oxidation and instead enable the resulting hydrocarbon groups to undergo partial oxidation or coupling to value-added products,” said Dr. Weaver.
Currently, direct catalytic processes to convert methane to chemicals are scarce and unsuitable for commercial use. The main difficulty is that most catalytic materials must operate at high temperatures to initiate chemical conversions of methane, however milder conditions are needed to direct the subsequent chemistry toward desirable products.
“Developing efficient catalytic processes to transform methane, the primary component of shale and natural gas, to more valuable products is a grand challenge for the chemical industry and would have significant economic and environmental benefits,” said Dr. Weaver. “The availability of new and cost-effective methane-to-chemicals processes could encourage the use of shale and natural gas as a chemical feedstock rather than a combustion fuel, thereby reducing greenhouse gas emissions and assisting in a transition toward renewable energy.”
This award will provide opportunities for high school and undergraduate students to participate in their research and focus on recruiting students from underrepresented groups to engage in these activities. The project also involves a collaboration with faculty in the Chemistry Department at Brookhaven National Laboratory. For a couple of weeks each year, UF students will work in the labs of Drs. Sanjaya Senanayake and Jose Rodriguez at BNL to conduct sensitive spectroscopic measurements of catalytic methane oxidation.
The Weaver Group focuses on advancing the understanding of reactions occurring on solid surfaces on a molecular level. Such reactions are fundamental to heterogeneous catalysis and semiconductor processing yet remain poorly understood at the molecular level. They investigate surface chemical reactions using analysis methods based on ultrahigh vacuum (UHV) surface chemistry and physics as well as in situ techniques.
Orazem Awarded Research Contract with Canada’s Nuclear Waste Management Organization
Mark Orazem, Ph.D., a Distinguished Professor and the Dr. and Mrs. Frederick C. Edie Professor, was awarded a three-year research contract from the Nuclear Waste Management Organization (NWMO) of Canada to develop a damage model of copper corrosion within nuclear fuel waste containers placed in deep geological repositories. The NWMO is responsible for the safe, long-term management of Canada’s used nuclear fuel.
A multiple-barrier system is designed to safely contain, and isolate used nuclear fuel and protect people and the environment. The present design of Canadian nuclear fuel waste containers consists of a thick-walled steel vessel coated with a thin copper layer intended to provide corrosion protection. Each of the five barriers provides a unique and stand-alone level of protection. If any of the barriers deteriorate, the next one comes into play.
Dr. Orazem and Chen You, a Ph.D. student in the Orazem lab, are developing a model to understand how the copper-coated container will withstand humidity inside the repository environment. This modeling will help the NWMO better understand the long life cycle of the repository.
Dr. Orazem is a renowned expert in corrosion modeling and has previously worked on other international deep geological repository projects, including the SKB project in Sweden, among many other industrial and public projects.
“The NWMO’s research has already demonstrated the multiple barrier system is a safe, long-term solution for used nuclear fuel. The work being done at the University of Florida by Dr. Orazem’s team will further underscore our safety assessment work and add more confidence in the copper-coated container’s ability to withstand any contact with moisture, even centuries in the future,” said Dr. Scott Briggs, an Associate Engineer with the NWMO. “The modeling being worked on will increase our confidence in the corrosion allowance — the amount of copper that can be damaged over time — while still ensuring the long-term integrity of the container.”
ORAZEM PARTICIPATES IN NATIONAL ACADEMIES VIRTUAL WORKSHOP
Dr. Orazem participated in a virtual workshop on Laboratory and Field Geotechnical Characterization for Improved Steel Corrosion Modeling on March 9-10, 2021. The workshop was organized by the National Academies of Sciences, Engineering, and Medicine.
“I discussed our efforts to model the cathodic protection of pipelines and the use of impedance spectroscopy to explore the properties of the steel-soil interface,” said Dr. Orazem. “I am honored to be asked to participate.”
Dr. Orazem contributes to the National Academies’ study of field, laboratory, and modeling methods for characterizing corrosion of steel buried in earth materials and knowledge of new developments in the prediction and monitoring of corrosion of steel in earth applications and environments.
The Rinaldi-Ramos Research Lab Investigates Nanoparticles as Diagnostic and Therapeutic Agents
Fast Nanoparticle Diffusion in Synovial Fluid may hold key to Joint Disease Recovery
The application of nanoparticles as diagnostic and therapeutic agents has been of great interest over the last few decades. Understanding the diffusion of nanoparticles in biological environments is critical in their design and eventual clinical application. However, there is incomplete understanding of nanoparticle diffusion in synovial fluid, the fluid inside the joint, which consists of a mixture of the polyelectrolyte hyaluronic acid, proteins, and other components.
University of Florida professors Carlos M. Rinaldi-Ramos, Ph.D., and Kyle D. Allen, Ph.D., from the Department of Chemical Engineering and the J. Crayton Pruitt Family Department of Biomedical Engineering, are investigating the application of nanoparticles as diagnostic and therapeutic agents for joint diseases, such as osteoarthritis. In a recent study published in Science Advances, their research provides new insight into the diffusion of nanoparticles in synovial fluid and their analogues through application of state-of-the-art instrumentation to measure the translational and rotational motion of these tiny materials in complex biological fluid environments.
The study, led by recent graduate Mythreyi Unni, Ph.D., (Ph.D. ChE ’19) is the first to report faster than expected nanoparticle translational and rotational diffusion in synovial fluid and in concentrated solutions of the polyelectrolyte hyaluronic acid, one of the principal components in synovial fluid. To achieve this, the team leveraged instrumentation at the UF to measure nanoparticle rotational diffusion and at the Advanced Photon Source (APS), a U.S. Department of Energy User Facility at DOE’s Argonne National Laboratory, to measure nanoparticle translational diffusion. The study was conducted in collaboration with scientists from Argonne and Poland’s AGH University of Science and Technology.
“Our results suggest that polyethylene glycol (PEG) coated nanoparticles should be able to rapidly diffuse throughout the synovial fluid, potentially reaching targets such as cartilage, synovium, and the cells within those tissues,” said Mythreyi Unni, Ph.D., first author of the paper.
Unni is a Ph.D. alumna in the Rinaldi-Ramos Research Laboratory lead by UF Department of Chemical Engineering Chair and Dean’s Leadership Professor, Carlos M. RinaldiRamos, Ph.D. The Rinaldi-Ramos Research Laboratory investigates biomedical applications of magnetic nanoparticles, and the stability and transport of nanoparticles in complex and biological fluids.
The work was performed using the ultrabright X-rays at the APS. UF students visited the APS several times over a period of two years to measure nanoparticle translational diffusion using a technique called x-ray photon correlation spectroscopy.
“Recent advances in ultrafast x-ray detectors and enhancements in coherence of the x-rays have enabled probing dynamics in biological systems, which paves the way for many such scientific breakthroughs,” said Suresh Narayanan, Ph.D., of Argonne, a co-author in the study.
Mythrei Unni, Ph.D. Ph.D. ChE ‘19
Carlos M. Rinaldi-Ramos Ph.D. and Mythreyi Unni, Ph.D.
“Although these findings are exciting, this is only the beginning. Future studies will provide insight into the role of nanoparticle properties, such as size and charge, and joint disease state, which affects the composition of synovial fluid, on nanoparticle diffusion. We expect that the knowledge gained through these studies will help design next generation nanoparticle drug carriers to treat joint diseases,” said Dr. Rinaldi-Ramos, the senior corresponding author in the study.
UF RESEARCHERS USE MAGNETIC CRYOPRESERVATION AGENTS TO EXTEND DONOR ORGAN PRESERVATION TIME
Researchers at UF are using colloidally stable nanoparticles and magnetic cryopreservation agents (mCPAs) to extend the preservation time of donor organs.
Currently, the preservation time window ranges from 4-36 hours depending on the organ. This time window severely restricts the time for adequate donor-to-recipient matching and the distance over which transplant organs can be offered. Researchers have been able to extend this time frame for up to one week without evidence of damage to the organ.
Since its inception, organ transplantation has saved millions of lives and improved the quality of life for many more. Despite advances in surgery and organ preservation technologies, about 70% of organs suitable for transplant are discarded. One critical reason is exceeding preservation time limits in taking organs from donors to potential recipients. are not ideally matched to recipients, based on size or immunological factors.
“Nanowarming of cryopreserved organs perfused with magnetic cryopreservation agents (mCPAs) could increase donor organ utilization by extending preservation time and avoiding damage caused by slow and non-uniform rewarming,” said Carlos M. Rinaldi-Ramos, Ph.D., principal investigator, Dean’s Leadership Professor and Chair, UF Department of Chemical Engineering.
Dr. Rinaldi-Ramos; Andreina Chiu-Lam, Ph.D.; Edward D. Staples, M.D., an associate professor in the division of thoracic and cardiovascular surgery in the UF College of Medicine, and Carl J. Pepine M.D., in the Division of Cardiovascular Medicine, have their findings published in Science Advances.
The promise of nanowarming for biobanking, also known as tissue banking, of whole organs relies on the ability to uniformly perfuse an organ, vitrify the organ, and rapidly rewarm the organ to room temperature, avoiding damage caused during the rewarming step. It also requires removal of the solutions containing biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) used to rewarm the organ.
The study results highlight the important role of SPION stability in formulating mCPA solutions and support the potential of nanowarming as a strategy for biobanking transplant tissues.
ChE Welcomes Two New Faculty Members
DEPARTMENT ENJOYS STEADY GROWTH WITH 12 NEW FACULTY HIRED SINCE FALL 2018
Won Tae Choi, Ph.D.
August 2021. Assistant Professor Ph.D., Georgia Institute of Technology
Won Tae Choi, Ph.D., joined the faculty of the Department of Chemical Engineering at the University of Florida as an assistant professor in
Dr. Choi’s research covers design, engineering, and analysis of electrochemically active soft materials for energy conversion and storage applications. He was trained on advanced techniques, such as scanning electrochemical microscopy and ultramicroelectrodes for fundamental electrochemical analysis.
Dr. Choi was a postdoctoral researcher under supervision of Prof. Allen J. Bard in the Department of Chemistry at The University of Texas at Austin. Prior to this, he worked in the corrosion research group under supervision of Prof. Preet M. Singh in the School of Materials Science and Engineering at Georgia Institute of Technology, where he earned knowledge and skills to investigate electrochemical reactions that occur at interfaces in harsh environment. He earned a Ph.D. degree in Chemical and Biomolecular Engineering from the Georgia Institute of Technology in 2017 under the supervision of Prof. Dennis W. Hess.
Sumant S. Patankar, Ph.D.
Professor in January 2021. Instructional Assistant Professor Ph.D., The Ohio State University
Sumant S. Patankar, Ph.D., has joined the faculty of the University of Florida Department of Chemical Engineering as an Instructional Assistant
Dr. Patankar’s research focused on studying the properties of supercritical fluids under nanopore confinement – a system relevant to geological systems such as shale gas. His teaching interests include semiconductor processing, and design and analysis of experiments.
Dr. Patankar received his bachelor’s degree in Chemical Engineering from the Institute of Chemical Technology (ICT), Mumbai, India. He earned a Ph.D. degree in Chemical Engineering from The Ohio State University in 2016 under the guidance of Dr. David Tomasko. He also worked for Intel Corp. in Hillsboro Oregon as a Process Engineer from 2017-2020. At Intel, he worked on developing lithography processes for the next generation of semi-conductor products.
Stoppel Awarded Department of Defense Grant to Develop an All-Natural Hemoglobin Carrier
Whitney L. Stoppel, Ph.D.,
an assistant professor, was awarded a Peer Reviewed Medical Research Program (PRMP)/Discovery Award from the Department of Defense (DoD) to develop all-natural, cost-effective, and pathogenfree oxygen carrying particles.
Oxygen is carried in our blood by a protein called hemoglobin which is inside red blood cells. Following a traumatic injury or in patients with other medical complications, the blood may not be able adequately deliver oxygen to the tissues throughout the body. In the hospital, patients can get a blood transfusion; however, there are situations which may prevent a patient from receiving a blood transfusion (e.g., medical complications, religious reasons) or other supply chain complications that lead to shortages in pathogen- or virus- free blood donations.
“We aim to address gaps in the field of oxygen therapeutics through the development of an all-natural silk protein-based material with controllable and tunable oxygen delivery capabilities using salmon hemoglobin. While we are currently focused on therapeutic oxygen delivery in patients, there may be additional applications for use in transplant organ preservation or other pharmaceutical delivery applications,” said Dr. Stoppel. “Our goal is to design and develop the particles so that they do not require refrigeration. This feature will make the technology easily adaptable to a broad range of places and patients.”
Dr. Stoppel is spearheading the project with Co-PI Bruce D. Spiess, MD, FAHA, in the Department of Anesthesiology at the UF College of Medicine. Dr. Spiess is a worldrenowned expert in the field of artificial oxygen carriers and alternatives to blood transfusions. Together, they will investigate how silk and salmon hemoglobin can be combined to improve the ability of the all-natural nanoparticles to deliver oxygen at clinically relevant rates.
Silk fibroin is a natural protein found in the cocoons of silkworms. The body can degrade it into simple protein building blocks without any extra efforts or adverse side effects. Silk fibroin nanoparticles make good carriers for bioactive molecules as shown by many others in the field. However, without the addition of a hemoglobin molecule or other artificial oxygen carrier, they don’t aid in oxygen delivery. The researchers aim to incorporate hemoglobin from fish into the silk particles. Fish use their hemoglobin to help them control their buoyancy in addition to keeping their bodies alive. The innovative part of this project is the unique combination of a novel fish hemoglobin with an allnatural silk-based particle.
The Stoppel Lab builds dynamic and adaptable natural biomaterials that can be leveraged to alter the behavior of cells both in vitro and in vivo for repair and rehabilitation of damaged or diseased tissue.
Promotions and Awards
David Hibbitts, Ph.D., was promoted to Associate Professor with tenure
Mark E. Orazem, Ph.D.,
was awarded the Doctoral Dissertation Advisor/ Mentoring Award from the Herbert Wertheim College of Engineering
Redefining the Scale of Unit Operations
Faculty miniaturized the experience students received in the lab.
When the world closed down due to the global pandemic, faculty in the UF Department of Chemical Engineering devised new ways to continue delivering the same high-quality education while remaining physically distant.
First used in Fall 2020, the Unit Operations Lab Kit, a low-cost, 3D printed kit was provided to each student to perform their own guided lab experiments at home. The kits included miniaturized versions of the equipment that they would utilize in the lab. Students were able to run their own guided experiments, analyze their own findings, and remain physically distant.
Fernando Mérida, Ph.D., an Instructional Assistant Professor, gave an update on the kits, and the lessons learned along the way.
Q: How have the kits been used in and outside of class?
A: Every student in the face-to-face (F2F) and online section received a box with materials required to run experiments including the 3D-printed prototypes (heat exchangers, fluidic devices, fixed bed columns, pipe connectors) and a long list of ancillary elements including pumps, electronics, sensors, plastic ware, etc. In the classroom, each student was working on a wide oval-shaped table with a large TV monitor that was used by the course instructor to project slideshows with introductory lectures, announcements, experimental procedures, etc., but students also had the freedom to connect their own computers to the TV monitor thus having experimental procedures visible at all times. Students in F2F sections brought their kit box every day of classes and took it back home once experiments were done for the day. Indeed, lots of logistics to coordinate! For students working remotely, logistics were simpler because they would keep their experimental setup in their desk at all times without the need of relocating it when compared to students in F2F sections. Experiments were conducted individually by each student, but individual results were consolidated in a group. At the end of the semester, most of the kit components were returned by students, however they were allowed to keep the 3D-printed prototypes as mementos!
Q: How did it work overall?
A: It worked very well! Lots of students were enthusiastic about working with these kits and despite a few technical difficulties (mostly, minor water spills and sensors not working due to electrical misconnections) occurring during kit assembly and experiment execution. Students had a good grasp of the underlying concepts of Fluid Mechanics and Heat Transfer by running these small-scale experiments. Of course, the small scale experiments will never replace the experience students can get in a Unit Operations Lab with larger equipment and instrumentation, but most students were aware of these limitations. On the other hand, there were some advantages of using small-scale experiments when compared to those traditionally conducted in the Unit Operations Lab. For example, students were able to set up experiments in multiple configurations which is something that, due to the larger scale, cannot be done (or at least not easily) in the lab. Due to this flexibility, the third week in each experimental module was used for “alternative experiments” - experiments not listed in lab manuals but open to the student’s creativity. And yes, we had lots of creative ideas including setting up pumps and heat
Fernando Mérida Ph.D., and his students using the Unit Operations Lab Kits. “CHEMICAL ENGINEERS SHOULD
NOT SCALE-UP PROCESSES FOR
INDUSTRIAL APPLICATIONS ONLY...
WE MUST MOVE IN BOTH
DIRECTIONS AND IN ALL SCALES.
THAT’S WHAT WE ARE DOING NOW
AT UF CHEMICAL ENGINEERING.”
Fernando Mérida, Ph.D. Instructional Assistant Professor
exchangers in series and parallel arrangements, using sewing & jewelry materials as packing for fixed bed columns, creating tubing coils to emulate flow restriction done by a valve, etc. Things got creative and nerdy!
Q: What challenges have you faced?
A: One of the greatest challenges was the increased amount of work not only for contact hours but also for material preparation, kit troubleshooting outside the class, grading, etc. Technical difficulties with kits in the classroom were easily solved in most cases, but those happening with students doing experiments at home were sometimes very hard to fix. As for students in F2F sections, a huge challenge was the transportation of kit materials from home to school and back every day of classes, and the need of assembling & disassembling everything over and over again. The latter is a challenge I experienced too; I was required to pickup everything after classes and leave the table clean and tidy because it was a shared space.
Q: What have you learned? Any surprises?
A: I learned that some of the things we were told as Chemical Engineering students regarding the scale-up nature of processes is not entirely true, or it should be redefined at the very least. Let me explain…Typically, our knowledge in Mathematics, Physics, and Chemistry allow Chemical Engineers to design processes that typically start in small laboratories with bench top equipment and then using our knowledge of Process Economics and Design, Optimization, and Unit Operations will help in scaling up the designed processes to meet the requirements of efficiency and sustainability of large manufacturing industries. While this is true, it does not mean that the same knowledge cannot be applied to flow in the opposite direction (from large to small) and this is something that is not traditionally taught in Chemical Engineering classes or projects unless they are dealing with a more research-oriented focus. By designing, creating, and incorporating these miniaturized experiments in a UO1 class both in-person and online, I learned that the same principles for scaling-up can also be used to scale-down processes, and that alternating or even combining the direction of scales is something we should start doing in the instruction of core and elective Chemical Engineering classes.
Q: What are the plans for the kits moving forward?
A: The plan for the kits is to keep using them as long as possible. Taking the lessons learned from using these kits for two semesters, along with great ideas from students, the Unit Operations class now has six experimental modules and three of them are hybrid: small- and pilot-scale experiments. Plans for subsequent semesters include coupling more miniaturized prototypes for existing modules with pilotscale experiments only. Did I mention before that designing Chemical Engineering processes should range in any direction of the scale? Well, I took it seriously and that has been implemented already in UO classes. Kits will also be available for outreach activities especially those aiming to increase the recruitment of undergraduate students to our program. Important core classes in Chemical Engineering such as Materials and Energy Balances, Fluid and Solids Operations and Energy Transfer Operations are encouraged to incorporate at least one experiment throughout the semester, so kits will also be available for this purpose.
