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Chemical and Biomolecular Engineering

Congratulations to Chemical and Biomolecular Engineering graduate student Johnny Ching-Wei Lee, who has been selected to receive the 2020 Prize for Outstanding Student Research from the Neutron Scattering Society of America.

Lee is a member of professor Simon Rogers’ lab. His research has focused on how molecules rearrange and affect the flow and deformation characteristics of soft materials, such as synthetic and biological polymers, under dynamically-changing flows.

“I’m deeply pleased and honored to receive this prestigious award,” said Lee, who wished to thank his advisor and his collaborators at the National Institute of Standards and Technology and Institut Laue-Langevin.

Johnny Ching-Wei Lee

NSSA established the prize to recognize outstanding accomplishments in neutron scattering by students who have performed much of their work at North American neutron facilities. Nominations are reviewed by a committee of experts in the field of neutron science.

The award will be presented at the society’s annual meeting this summer.

Lee completed his undergraduate studies at National Taiwan University and joined the University of Illinois Department of Chemical and Biomolecular Engineering as a graduate student in 2015.

His work involves characterization and molecular design of synthetic and biological soft materials under flows. He combines advanced rheological methods with neutron scattering techniques to simultaneously monitor the macroscopic material response and in-situ molecular rearrangements. He has successfully unveiled complex structure-rheology correlations, leading to new design criteria for soft materials.

After he graduates from Illinois with his PhD in Chemical Engineering, Lee plans to join Corteva as a research scientist with its Formulation Science and Technology R&D Team.

Chemical and Biomolecular Engineering graduate student Johnny Ching-Wei Lee (left), Professor Simon Rogers (right) and collaborators are challenging previous assumptions regarding polymer behavior with their newly developed laboratory techniques that measure polymer flow at the molecular level. Photo by L. Brian Stauffer.

Before designing the next generation of soft materials, researchers must first understand how they behave during rapidly changing deformation. In a new study, researchers challenged previous assumptions regarding polymer behavior with newly developed laboratory techniques that measure polymer flow at the molecular level.

This approach may lead to the design of new biomedical, industrial and environmental applications – from polymers that aid in blood clotting to materials that more efficiently extract oil and gas from wells.

The findings are published in the journal Physical Review Letters.

Understanding the mechanics of how materials molecularly react to changing flows is critical to developing high-quality materials, the researchers said, and defining a framework for interpreting and describing these properties has eluded scientists for decades.

“When polymeric materials – synthetic or biologic – are deformed, they react at both macroscopic and molecular scales,” said Simon Rogers, a University of Illinois chemical and biomolecular engineering professor and lead author of the new study. “The relationship between the two scales of response is complex and has been, until now, difficult to describe.”

Previous studies have attempted to characterize the relationship between the microscopic and macroscopic behaviors of polymer deformation mathematically, the researchers said, but have been unable to relate the physics to any well-defined microstructural observations.

“In our study, we wanted to measure both the structural and mechanical properties of polymers during deformation, directly shedding light on the origin of unique mechanical properties,” said Johnny Ching-Wei Lee, a graduate student and study co-author. “We thought perhaps it was best to try and use direct observations to explain the complex physics.”

In the lab, the researchers simultaneously measured multiscale deformations by combining traditional tools for measuring stress and deformation at the macroscopic level with a technique called neutron scattering to observe the structure at the molecular scale.

The team found something unexpected.

“With simultaneous neutron scattering and flow measurements, we are able to directly correlate structure and mechanical properties with a time resolution on the order of milliseconds, ” said study co-author Katie Weigandt, a researcher from the National Institute of Standards and Technology Center for Neutron Science. “This approach has led to fundamental understanding in a wide range of nanostructured complex fluids, and in this work, validates new approaches to making polymer flow measurements. ”

“Previous research had assumed that the amount of applied deformation at the macroscale is what soft materials experience at the microscale,” Lee said. “But the neutron-scattering data from our study clearly shows that it is the deformation that can be recovered that matters because it dictates the whole response, in terms of macroscopic flow – something that was previously unknown.”

The researchers said this development will help rectify several poorly understood phenomena in polymers research, such as why polymers expand during three-dimensional printing processes.

“We have come up with what we call a structure-property-processing relationship,” Rogers said. “This subtle, yet fundamentally different way of thinking about the polymer behavior summarizes what we see as a simple and beautiful relationship that we expect to be quite impactful.”

The research brings key insights to the long-standing challenge in soft condensed matter, and the team said the established structure-property-processing relationships could provide a new design criterion for soft materials.

Katie M. Weigandt and Elizabeth G. Kelley of the Center for Neutron Research at the National Institute of Standards and Technology also contributed to the study.

The National Science Foundation supported the research.

To reach Simon Rogers, call (217) 333-0020; sarogers@illinois.edu

The paper “Structure-property relationships via recovery rheology in viscoelastic materials” is available online and from the U. of I. News Bureau.

DOI: 10.1103/PhysRevLett.122.248003

Simon Rogers, assistant professor of chemical and biomolecular engineering, has won a National Science Foundation Early CAREER Award for his research proposal on understanding the ways soft materials transition from acting as solids to acting as liquids.

The National Science Foundation’s Faculty Early Career Development Program’s CAREER Awards are prestigious and competitive awards given to junior faculty who exemplify the role of teacher-scholar through outstanding research, excellent education, and the integration of education and research within the context of the mission of their respective organizations.

“I’m honored and excited to receive this award. It’s a great chance to pursue my research goals over an extended period of time and to have the chance to train and inspire the next generation of soft matter scientists,” Rogers said. The award is a reflection of the hard work of my students, and of the expert mentoring I’ve received from my senior colleagues.”

Simon Rogers, assistant professor of chemical and biomolecular engineering

The title of his proposal is, “Time-dependent Structures of Soft Materials under Flow: A Rheo-Scattering Approach to the Study of Thixotropic Yield Stress Fluids.”

Yield-stress materials can be utilized in a variety of ways—in 3D printing applications, pharmaceuticals, photovoltaics, food, and more. No matter their application, yield-stress materials need to retain a desired shape under certain conditions but also be able to flow on demand. In some types of 3D printing, for instance, it’s important to use inks that can flow out of a nozzle but then turn into solids once printed, allowing for a variety of structures to be formed.

“We seek to understand these behaviors at a molecular level, so we can design and engineer smart responsive materials for a variety of applications,” Rogers said. Currently, however, there is no accurate way of determining the precise conditions under which these materials yield.

For this project, Rogers and members of his lab will develop experimental methods that link the mechanical changes we observe on human length scales to what happens at a molecular level. This will enable the design of new materials as well as more efficient industrial processes.

The NSF CAREER program will provide five years of support to Rogers’ research as well as a number of public engagement activities for school-age children and mentorship for undergraduate and graduate students. Members of the Rogers Lab will teach budding scientists about the complexity of soft matter research through programs that target underrepresented groups. In addition, undergraduate classes will be enhanced by incorporation of higher-level material obtained through this work.

Stiff microbial films often coat medical devices, household items and infrastructure such as the inside of water supply pipes, and can lead to dangerous infections. Researchers have developed a system that harnesses the power of bubbles to propel tiny particles through the surfaces of these tough films and deliver an antiseptic deathblow to the microbes living inside.

Biofilms are slimy colonies of microbes held together by internal scaffolds, clinging to anything they touch. About 80 percent of all medical infections originate from biofilms that invade the inner workings of hospital devices and implants inside patients. Eradication is difficult because traditional disinfectants and antibiotics cannot effectively penetrate a biofilm’s tough surface, the researchers said.

In the journal ACS Applied Materials and Interfaces, a team led by researchers at the University of Illinois at Urbana-Champaign describes how they used diatoms – the tiny skeletons of algae – loaded with an oxygen-generating chemical to destroy microbes.

From left: Simon Rogers, professor of Chemical and Biomolecular Engineering; Jun Pong Park, postdoc; Yongbeaom Seo, postdoc; and Hyunjoon (Joon) Kong, professor of Chemical and Biomolecular Engineering. Photo by L. Brian Stauffer.

“Most of us get those black or yellow spots in our showers at home,” said co-author Hyunjoon Kong, a professor of chemical and biomolecular engineering and a Carle Illinois College of Medicine affiliate. “Those spots are biofilms and most of us know it takes a lot of energy to scrub them away. Imagine trying to do this inside the confined space of the tubing of a medical device or implant. It would be very difficult.”

Looking to nature and basic mechanics for a solution, the researchers developed a system that uses naturally abundant diatoms along with hydrogen peroxide and tiny oxygen-generating sheets of the compound manganese oxide.

“We could have fabricated a particle using 3D printers, but luckily nature already provided us with a cheap and abundant option in diatoms,” said co-author and postdoctoral researcher Yongbeom Seo. “The species of diatom we selected are hollow, highly porous and rod-shaped, providing a lot of surface area for the bubbles to form and a channel for the bubbles to escape.”

The chemical reaction between the hydrogen peroxide and manganese oxide nanosheets takes place within the empty space inside the diatom. The result is a flourish of microbubbles that flow through the tiny channel, propelling the rigid diatoms forward with enough force to break up the surface and internal structure of the biofilms, the researchers said.

“We dope the particles with nanosheets of manganese oxide, then mix them with hydrogen peroxide and apply that to the surface of the biofilm,” Kong said. “Once the diatoms break through to the internal structure of the biofilm, they continue to expel bubbles and facilitate the entry of hydrogen peroxide, which is an effective disinfectant against bacteria and fungus.”

The researchers believe that their success is a result of a decision to focus on the mechanical aspects of biofilm destruction, not the chemical aspects of simply killing microbes.

“We have arrived at a mechanistic solution for this problem and the possibilities for this technology are endless,” said co-author Simon Rogers, a professor of chemical and biomolecular engineering. “We are discussing our research with clinicians who have many exciting ideas of how to use this system that we did not even think of originally, such as the removal of dental plaque.”

U. of I. researchers Jiayu Leong, Jun Dong Park, Yu-Tong Hong, Yu-Heng Deng, Vitaliy Dushnov and Joonghui Soh also contributed to this study. Additional co-authors include Sang-Hyon Chu of the National Institute of Aerospace, Cheol Park of the NASA Langley Research Center, Dong Hyun Kim of the Korea Institute of Industrial Technology and Yi Yan-Yang of the Institute of Bioengineering and Nanotechnology in Singapore.

The National Institutes of Health, the National Science Foundation and the Korea Institute of Industrial Technology supported this research.

Written by Lois Yoksoulian, U of I News Bureau

Editor’s notes:

To reach Hyunjoon Kong, call 217-333-1178; hjkong@illinois.edu.

The paper “Diatom microbubbler for active biofilm removal in confined spaces” is available online and from the U. of I. News Bureau. DOI: 10.1021/acsami.8b08643

From extracting DNA from strawberries, to making silly putty, to operating lab equipment, the 24 high school girls who participated in the Chemical and Biomolecular Engineering GAMES (Girls’ Adventures in Math, Engineering, and Science) camp this summer got to experience a bit of what chemical engineering is like. After hearing mini-lectures about a variety of chemical-engineering-related themes, the girls got to do fun, hands-on activities about the subject. Plus, during field trips, the girls got to see first-hand what a career in chemical engineering might be like. Even more importantly, they were exposed to women in chemical engineering who served as role models.

Extracting DNA from strawberries.

Director of the Chemical Engineering GAMES camp, Assistant Professor Diwakar Shukla, and a team of students from his lab led a number of activities, such as making foaming face wash. The campers also participated in a number of hands-on activities where they learned about and got a chance to do procedures using some of the lab equipment: they learned about pumps; DNA extraction, during which the girls extracted DNA from strawberries; the polymer extruder; enzymatic cleaning; continuous distillation; and acid rain. Students also took field trips, such as to the Abbott Power Plant and to the Urbana & Champaign Sanitary District’s waste water treatment facility.

Although Shukla and his students led several activities, he explained that he was just coordinating the ChBE GAMES camp and had lots of help from his colleagues. “The best part has been that nearly half of the faculty in our department—they decided to do a one-and-a-half-hour activity about their own lab. I’m just an organizer who is making sure the schedules are fixed and everything is in place.”

Using enzymes to clean.

Most of these faculty activities usually consisted of a short lecture about a subject, then a hands-on activity related to it. During the course of the week, the students learned about polymers and recycling from Dr. Sing & Dr. Guironnet; Dr. Kong taught about biotransportation, then he and his students led a hydrogel activity. Dr. Diao and her students taught about “Crystals All Around Us,” then led a crystal-making activity. Dr. Flaherty and his grad students taught about catalysis, surface science, and materials science, then led an activity on catalysis. Dr. Kraft and her students did an activity that involved making gold nanoparticles, which are used for immunoelectron microscopy. And finally, Shukla and his team taught and led an activity about computational games.

“I really enjoy teaching undergraduates and you know, this is even a lower level than undergrads. So there are always a lot of interesting questions, and it’s a lot of fun to teach them basic scientific ideas and get them curious about chemical engineering and, in general, engineering and STEM fields,” Shukla said.

Shukla has been actively working to increase the number of women in STEM.

Learning how the pump equipment works.

“Since I came to Illinois, I have always tried to take at least one female student in my group every year, as a graduate student, which is very difficult for a computational group. So at this point, my lab has five female students doing computer science and biology and chemical engineering.”

Did Shukla see any future chemical engineers in the group of high schoolers?

“Yes, they are all very curious,” he said. “They’re already talking about what type of courses they can take and credit transfers. So they’re asking very detailed questions about the program already. Some of them have clearly made up their mind that they will apply to an engineering school. But there are others who are freshmen, so they are really exploring.”

Story and photos by Elizabeth Innes, Communications Specialist, I-STEM Education Initiative.

The National Science Foundation has awarded a $1.2 million, three-year grant to four professors in Chemical and Biomolecular Engineering for a project that has potential to advance the frontiers of 3-D printing. Drs. Charles Sing, Ying Diao, Damien Guironnet, and Simon Rogers intend to create a platform for designing advanced materials that allows makers to tune the structure and function of a material on-the-fly.

Not long after arriving on campus, the team of investigators, each an assistant professor with a different research background and set of skills, got together to brainstorm what intriguing challenges they could solve together. Take camouflage. Camouflage is only effective as long as the person wearing it remains crouched in the jungle or standing by a sand dune in the desert. What if you had a material that could provide camouflage in many different environments, and you control how it works? Chameleons change color by adjusting skin structure at nanometer-length scales. Could humans design something similar with advanced materials processing?

“What we’re talking about is making a device, an object, instrument, from ostensibly the same material. It has different properties in different parts of the material,” Rogers said. Imagine a Lego brick that has one transparent wall, but the brick is made from all the same material. There’s one material with different properties, and the maker controls the material’s properties.

The project has two overarching goals: develop a screening method for versatile, 3-D printable block copolymer materials, which are two or more different polymer chains linked together; and screen to optimize flow-based tuning of morphology in 3-D printed materials. That entails testing their hypothesis that tuning the flow in 3-D printing will allow for on-the-fly or on-demand manipulation. Insights gained from their research could have potential applications in camouflage, antireflection coatings, metamaterials and displays.

Professors Ying Diao, Damien Guironnet, Charles Sing and Simon Rogers

For this project, each faculty member brings a distinct set of skills and expertise. Charles Sing, who works in molecular simulation and theory, will provide what he described as a treasure map. His research will guide the synthesis that occurs in the lab of Damien Guironnet, the self-described “cook.” Because Sing will be predicting some of the molecule’s properties beforehand, Guironnet will be able to synthesize the molecules that will make the polymers with the unique structure needed for the process.

From there, the material is handed over to Simon Rogers and members of his lab, who carefully control different flow conditions and investigate how the structures reorganize. Rogers then feeds information gleaned from his experiments and analysis to Ying Diao’s group. Diao will take the novel molecule and, with the knowledge of how this material reacted to Rogers’ experiments, she will attempt to make a functional material using 3-D printing.

Rogers then feeds information gleaned from his experiments and analysis to Ying Diao’s group. Diao will take the novel molecule and, with the knowledge of how this material reacted to Rogers’ experiments, she will attempt to make a functional material using 3-D printing.

“One key issue we’re interested in is the assembly, how to direct the assembling of the materials because it’s critical to the function,” Diao said. “In this case, we’re interested in the photonic properties. Can we potentially make camouflage using this functional material by assembling the material into highly ordered structures? We’ll be able to sensitively modulate the structure over length scales predicted by Charles Sing.”

What they’re doing could be called a “high-risk, high-reward” type of project, Diao said, because proposing to physically change structure on the fly is a fairly new idea. “The challenge is, how the assembly of this novel class of materials respond to flow is previously unknown. Flow-directed 3D printing is also not demonstrated before and requires significant innovation to realize,” she said.

Faculty anticipate discoveries and some surprises along the way because the material they’ll be working with is new and the process, called non-equilibrium processing, is still a relatively new concept, they said.

The grant comes from the NSF’s Designing Materials to Revolutionize and Engineer our Future (or DMREF) program, which specifically funds projects that aim to develop advanced materials quickly and at a fraction of the cost.

What makes the project unique is each investigator has a role to play in each other’s research. Due to the iterative, multi-project investigator structure, there will be a lot of coordination involved and each faculty member will need to understand results from their colleagues to be able to apply it to their own research.

“It’s an exciting challenge,” Guironnet said. “We get the opportunity to understand each other’s work to increase the impact of our own research. And at the same time, I get to extend my expertise as well,” he said.

What’s also unique about the group is that each investigator is an assistant faculty member. They all joined the department within about a year of each other.

“Because we’re new professors, there’s been a focus on building our own reputations, our own lab expertise. This is our moment to do something bigger than that, and that is extremely exciting,” Sing said.

Thanks to the NSF funding, faculty also plan to expand their outreach projects in computation, characterization and synthesis, via the Girls’ Adventures in Math, Engineering and Science (GAMES) summer camp and the St. Elmo Brady STEM Academy, which exposes underrepresented elementary students to STEM fields.

More information about the grant can be found here.

 

The University of Illinois Department of Chemical and Biomolecular Engineering and the Department of Mechanical Science and Engineering are pleased to announce that Anton Paar, a leading laboratory equipment company which makes high end instrumentation for material characterization, will provide state-of-the-art instruments to two faculty members to support their work on advancing fundamental and applied research in the field of rheology.

IMG_5943
Simon Rogers, members of his research group and Anton Paar officials gather around the new rheometer.

Anton Paar is loaning Illinois researchers Simon Rogers and Randy Ewoldt each with a top-of-the-line rheometer which will be fully loaded with accessories to allow maximum flexibility to characterize different types of complex fluids such as polymer solutions, colloidal suspensions, micellar solutions, and surfactant monolayers.

“The Rogers lab is extremely grateful to Anton Paar for the confidence they have expressed in our future with this agreement. We will be pushing rheological research forward, in our own little way, with this instrument and the support from Anton Paar,” said Simon Rogers, Assistant Professor of Chemical and Biomolecular Engineering. His research group investigates the fundamental physics behind time dependent phenomena exhibited by soft condensed matter systems under deformation for biomedical, energy, and environment applications.

A celebration to mark the partnership was held April 3. Anton Paar personnel spent the week installing the rheometers and offering training and demonstrations of the instruments’ capabilities.

“The new equipment brings incredible capabilities to our lab, which we plan to leverage and build upon with several research projects,” said Randy Ewoldt, Assistant Professor of Mechanical Science and Engineering. The Ewoldt group studies rheology, non-Newtonian fluid mechanics, mathematical modeling, and design involving soft materials. His work often involves interdisciplinary collaborations and is a combination of experiment and theory.

Anton Paar, which was established in 1922, develops, produces and distributes laboratory instruments as well as process measuring systems and provides custom-tailored automation and robotics solutions worldwide.

The company was looking to collaborate with researchers who “‘think outside the box’ for novel new ways to use research rheometers, especially folks who have a vision for new rheological test method developments which can impact both fundamental and applied research. Both Ewoldt and Rogers are collaborative researchers, and their work in rheology has a number of diverse applications ranging from biomedical, energy, and environmental to designing of soft materials, said Abhi Shetty, Lead Scientist at Anton Paar.

IMG_5982
A close-up of the rheometer.

Ewoldt and Rogers’ labs will receive MCR 702 TwinDrive rheometers, valued at approximately $600,000 total. This is the most advanced rheometer to date, according to the company. The model boasts several advantages, such as allowing researchers to perform rheological tests with two torque transducers and drive units at once. Operating two Electronically Commutated (or EC) motors at once opens up new possibilities, such as counter-rotation. This mode is an invaluable option for microscopy applications, according to Abhi Shetty, Lead Scientist at Anton Paar. Both researchers will receive the microscopy set-ups.

IMG_5914
Chemical and Biomolecular Engineering Department Head Dr. Paul Kenis, Mechanical Science and Engineering Department Head Anthony Jacobi, Randy Ewoldt and Simon Rogers with members of the Anton Paar team.

Rogers said some of his current experiments take a lot of time and effort, and with the new instrument, researchers will be able to “be more productive faster.”
“We’ll also be able to perform tests that just aren’t possible on other instruments,” he added.

The equipment will be loaned to the university for three years, with the possibility of extending the term for another two years. As part of the agreement, the researchers will conduct beta testing of new accessories.

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