CBE Professor William Mustain and Ph.D. candidate Ying Liu have reported, in a paper published in the February issue of the Journal of the American Chemical Society (J. Am. Chem. Soc., 2013, 135(2), pp 530–533; DOI: 10.1021/ja307635r), that a new catalyst material using tin-doped indium oxide (ITO) nanoparticles (NPs) as a high stability non-carbon support for platinum (Pt) nanoparticles has great potential as a next-generation catalyst for the oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells. As Liu and Mustain explain in their paper: “Sn was employed as the In2O3 dopant to exploit the strong interaction between Sn and Pt that was previously reported to enhance the activity of Pt on Pt/SnO2, while concomitantly avoiding the intrinsic stability limitations of SnO2 and leveraging the high stability of bulk In2O3 at ORR relevant potentials” This Pt/ITO catalyst showed mass activity that far surpassed the 2015 U.S. Department of Energy goal for Pt mass activity, and the stability of the Pt/ITO was remarkable under harsh conditions. In the future, Dr. Mustain and Ms. Liu will continue to improve the long-term stability of Pt/ITO and investigate its performance in PEM fuel cell stacks.
Structure and Performance of Pt/ITO Electrocatalysts
Republished with permission of Momentum,
a School of Engineering electronic publication
Doctoral candidates Neil Spinner and Ying Liu (Chemical & Biomolecular Engineering) have received John Tanaka Graduate Student Fellowship awards, which are presented to outstanding University of Connecticut graduate students who are members of Phi Kappa Phi, the nation’s oldest honor society.
Just two awards are presented annually.
“Both Neil and Ying are model graduate students. They are smart, hard-working, dedicated researchers. I am very proud of both of them – I could not think of two more qualified students for this award,” says Dr. William Mustain, their thesis advisor.
The John Tanaka Award, first given in 1993, was established in honor of Dr. John Tanaka, emeritus professor of chemistry and former Director of the Honors Programs. Dr. Tanaka, who died in April 2012, led the Phi Kappa Phi chapter for many years.
Selection is based on an applicant’s promise of success in graduate or professional study as evidenced by: academic achievement, relevant research experience, service and leadership experience on and off campus, and personal and career goals.
Ying, who has nine archival publications in high impact journals, is researching novel electrocatalysts for proton exchange membrane fuel cells, which is expected to play a significant role in providing clean, sustainable power for the 21st century and beyond. In nominating Ying for the honor, Dr. Mustain noted “…her most important mentoring and leadership has occurred in the laboratory where she has worked side-by-side with five of our young undergraduates.”
In his graduate research, Neil is synthesizing first generation electrocatalysts for the electrochemical synthesis of fuels at room temperature, with very low required energy input, and has used the results to develop design criteria for next generation catalysts. As a National Science Foundation GK-12 Fellow from 2010-12, Neil mentored students at Howell Cheney Technical High School in Manchester, CT and has contributed toward the UConn Mentor Connection and the Joule Fellows programs at UConn.
On April 13th and 14th, thirteen UConn Chemical Engineering students took part in the American Institute of Chemical Engineers (AIChE) Regional Conference at UMass-Amherst.
While at the conference, the students participated in AIChE’s ChemE Car competition. This competition challenges students to build a car that can travel between 15 and 30 meters, carrying anywhere between 0 and 500 grams. Students are not told the exact numbers until the day of the competition, at which time they are allowed to make minor adjustments to suit the requirements. The competition’s rules stipulate that the car must be autonomous, powered by chemical reaction, and without mechanical or electrical brakes. In addition to the car, each group creates a poster explaining their car—the chemical reaction that powers it, stopping mechanism, safety features, design, circuitry, and special features. The UConn team, advised by Dr. William Mustain, placed first of nine teams in this poster competition.
This was the first time UConn has sent a car to compete at the conference. Though the UConn group’s car, named “Harold Chegger,” did not place in the competition, the team is all very pleased with its performance. The group is looking forward to refining the car for competition next year.
In addition to participating in the competition, the group was invited by Governor Malloy to present their car at the Next Gen CT news conference, held on April 11th. The event highlighted the growing support among industry, legislature, faculty, and students for the Next Generation Connecticut initiative. This proposal would support UConn’s expansion in the STEM (science, technology, math, and engineering) disciplines.
It is now possible to connect with the UConn Chemical & Biomolecular Engineering Department using the popular professional networking website, LinkedIn. This will be a useful tool for university professors, members of academia, alumni, graduate and undergraduate students, and industry and public sector partners alike, because a LinkedIn connection with Chemical Engineering gives professionals access to a wide range of information and services. By connecting with CBE, members will have access to departmental jobs, news, and updates, as well as general career advice, job opportunities, and professional connections. Follow the link to access the membership page!
Republished with permission of emagination, a School of Engineering electronic publication
The 2012 Mentor Award of the American Association for the Advancement of Science (AAAS) will be presented to Dr. Cato T. Laurencin, M.D., Ph.D., “for his transformative impact and scientific contributions toward mentoring students in the field of biomedical engineering.”
Dr. Laurencin is the Albert and Wilda Van Dusen Distinguished Chair Professor of Orthopaedic Surgery and Professor of Chemical, Materials and Biomolecular Engineering at UConn. The Director of both the Raymond and Beverly Sackler Center, and the Institute for Regenerative Engineering at UConn, he is one of only two designated University Professors in the School of Engineering.
Throughout his distinguished career, Dr. Laurencin has taken significant steps to ensure that the impact of his pioneering work in biomaterials and tissue engineering benefits both the research community and, through his mentoring, future scientists and engineers. In 2011, he was elected to the National Academy of Engineering (NAE), among the nation’s highest professional distinctions accorded to an engineer, for his work in biomaterials science, drug delivery, and tissue engineering involving musculoskeletal systems, and his academic leadership.
Brian Willis, associate professor of chemical, materials, and biomolecular engineering, in his lab, with an X-ray photoelectron spectrometer. (Sean Flynn/UConn Photo)
A novel fabrication technique developed by UConn engineering professor Brian Willis could provide the breakthrough technology scientists have been looking for to vastly improve today’s solar energy systems.
For years, scientists have studied the potential benefits of a new branch of solar energy technology that relies on incredibly small nanosized antenna arrays that are theoretically capable of harvesting more than 70 percent of the sun’s electromagnetic radiation and simultaneously converting it into usable electric power.
The technology would be a vast improvement over the silicon solar panels in widespread use today. Even the best silicon panels collect only about 20 percent of available solar radiation, and separate mechanisms are needed to convert the stored energy to usable electricity for the commercial power grid. The panels’ limited efficiency and expensive development costs have been two of the biggest barriers to the widespread adoption of solar power as a practical replacement for traditional fossil fuels.
But while nanosized antennas have shown promise in theory, scientists have lacked the technology required to construct and test them. The fabrication process is immensely challenging. The nano-antennas – known as “rectennas” because of their ability to both absorb and rectify solar energy from alternating current to direct current – must be capable of operating at the speed of visible light and be built in such a way that their core pair of electrodes is a mere 1 or 2 nanometers apart, a distance of approximately one millionth of a millimeter, or 30,000 times smaller than the diameter of human hair.
“This new technology could get us over the hump and make solar energy cost-competitive with fossil fuels. ”
The potential breakthrough lies in a novel fabrication process called selective area atomic layer deposition (ALD) that was developed by Willis, an associate professor of chemical, materials, and biomolecular engineering and the previous director of UConn’s Chemical Engineering Program. Willis joined UConn in 2008 as part of an eminent faculty hiring initiative that brought an elite team of leaders in sustainable energy technology to the University. Willis developed the ALD process while teaching at the University of Delaware, and patented the technique in 2011.
Illustration of a working nanosized optical rectifying antenna or rectenna. (Image courtesy of Brian Willis)
It is through atomic layer deposition that scientists can finally fabricate a working rectenna device. In a rectenna device, one of the two interior electrodes must have a sharp tip, similar to the point of a triangle. The secret is getting the tip of that electrode within one or two nanometers of the opposite electrode, something similar to holding the point of a needle to the plane of a wall. Before the advent of ALD, existing lithographic fabrication techniques had been unable to create such a small space within a working electrical diode. Using sophisticated electronic equipment such as electron guns, the closest scientists could get was about 10 times the required separation. Through atomic layer deposition, Willis has shown he is able to precisely coat the tip of the rectenna with layers of individual copper atoms until a gap of about 1.5 nanometers is achieved. The process is self-limiting and stops at 1.5 nanometer separation.
The size of the gap is critical because it creates an ultra-fast tunnel junction between the rectenna’s two electrodes, allowing a maximum transfer of electricity. The nanosized gap gives energized electrons on the rectenna just enough time to tunnel to the opposite electrode before their electrical current reverses and they try to go back. The triangular tip of the rectenna makes it hard for the electrons to reverse direction, thus capturing the energy and rectifying it to a unidirectional current.
Impressively, the rectennas, because of their incredibly small and fast tunnel diodes, are capable of converting solar radiation in the infrared region through the extremely fast and short wavelengths of visible light – something that has never been accomplished before. Silicon solar panels, by comparison, have a single band gap which, loosely speaking, allows the panel to convert electromagnetic radiation efficiently at only one small portion of the solar spectrum. The rectenna devices don’t rely on a band gap and may be tuned to harvest light over the whole solar spectrum, creating maximum efficiency.
The federal government has taken notice of Willis’s work. Willis and a team of scientists from Penn State Altoona along with SciTech Associates Holdings Inc., a private research and development company based in State College, Pa., recently received a $650,000, three-year grant from the National Science Foundation to fabricate rectennas and search for ways to maximize their performance.
“This new technology could get us over the hump and make solar energy cost-competitive with fossil fuels,” says Willis. “This is brand new technology, a whole new train of thought.”The Penn State Altoona research team – which has been exploring the theoretical side of rectennas for more than a decade – is led by physics professor Darin Zimmerman, with fellow physics professors Gary Weisel and Brock Weiss serving as co-investigators. The collaboration also includes Penn State emeritus physics professors Paul Cutler and Nicholas Miskovsky, who are principal members of Scitech Associates.“The solar power conversion device under development by this collaboration of two universities and an industry subcontractor has the potential to revolutionize green solar power technology by increasing efficiencies, reducing costs, and providing new economic opportunities,” Zimmerman says.“Until the advent of selective atomic layer deposition (ALD), it has not been possible to fabricate practical and reproducible rectenna arrays that can harness solar energy from the infrared through the visible,” says Zimmerman. “ALD is a vitally important processing step, making the creation of these devices possible. Ultimately, the fabrication, characterization, and modeling of the proposed rectenna arrays will lead to increased understanding of the physical processes underlying these devices, with the promise of greatly increasing the efficiency of solar power conversion technology.”
Brian Willis holds a rectenna device. (Sean Flynn/UConn Photo)
The atomic layer deposition process is favored by science and industry because it is simple, easily reproducible, and scalable for mass production. Willis says the chemical process is already used by companies such as Intel for microelectronics, and is particularly applicable for precise, homogenous coatings for nanostructures, nanowires, nanotubes, and for use in the next generation of high-performing semi-conductors and transistors.
Willis says the method being used to fabricate rectennas also can be applied to other areas, including enhancing current photovoltaics (the conversion of photo energy to electrical energy), thermoelectrics, infrared sensing and imaging, and chemical sensors.
A 2011 seed grant from UConn’s Center for Clean Energy Engineering allowed Willis to fabricate a prototype rectenna and gather preliminary data using ALD that was instrumental in securing the NSF grant, Willis says.
Over the next year, Willis and his collaborators in Pennsylvania plan to build prototype rectennas and begin testing their efficiency. Willis compares the process to tuning in a station on a radio.
“We’ve already made a first version of the device,” says Willis. “Now we’re looking for ways to modify the rectenna so it tunes into frequencies better. I compare it to the days when televisions relied on rabbit ear antennas for reception. Everything was a static blur until you moved the antenna around and saw the ghost of an image. Then you kept moving it around until the image was clearer. That’s what we’re looking for, that ghost of an image. Once we have that, we can work on making it more robust and repeatable.”
Willis says finding that magic point where a rectenna picks up maximum solar energy and rectifies it into electrical power will be the champagne-popping, “ah-ha” moment of the project.
“To capture the visible light frequencies, the rectenna have to get smaller than anything we’ve ever made before, so we’re really pushing the limits of what we can do,” says Willis. “And the tunnel junctions have to operate at the speed of visible light, so we’re pushing down to these really high speeds to the point where the question becomes ‘Can these devices really function at this level?’ Theoretically we know it is possible, but we won’t know for sure until we make and test this device.”
Assistant Professor Anson W. Ma (Photo courtesy of Peter Morenus/UConn)
Professor Anson Ma of the Chemical Engineering Program has received the CAREER award (#1253613) from the National Science Foundation (NSF). The Faculty Early Career Development (CAREER) Program is NSF’s most prestigious award for junior faculty, reserved for those who embody the role of “teacher-scholars” by seamlessly integrating outstanding research and excellent education. Ma’s award is given by the Fluid Dynamics Program of the Chemical, Bioengineering, Environmental, and Transport Systems (CBET) Division. The award provides $400,000 in research funding support over a period of 5 years.
The title of Dr. Ma’s winning proposal is “Understanding the interfacial rheology of carbon nanotubes at the fluid-fluid interfaces for creating ultra-stable emulsions and microcapsules”. Particles of appropriate size and wetability are known to stabilize emulsions, but the effect of particle shape remains largely unexplored. Dr. Ma and team propose that the shape matters and that particle shape could be the missing key to unlock the full potential of using particles to stabilize emulsions. To this end, Dr. Ma and his team will investigate the flow behavior of CNTs at fluid-fluid interfaces using carbon nanotubes as a model system. The success of the proposed research will offer a general and yet relatively simple strategy (i.e., by exploiting particle shape) to improve the stability of emulsions, prolonging the shelf life of widely used pharmaceutical, agricultural, and personal care products. The findings may also revolutionize the use of nanoparticles for enhanced oil recovery, essential to ensuring national energy independence and addressing the world’s energy challenge.
Further, Dr. Ma has a long-term vision that the asymmetry of the interface may offer an effective way to assemble nanoparticles into ordered structures and to create next-generation metamaterials. Metamaterials are hierarchically ordered structures that can be used in cloaking devices and light-based circuits that may ultimately outperform electron-based computers in terms of speed, power consumption, and costs. The proposed research will be integrated with educational and outreach activities at all levels to maximize its impact. Dr. Ma and his team will use culinary foams and emulsions (e.g., cappuccino foam, ice cream mix) as the theme to introduce basic scientific concepts to the younger generation and the local community.
Dr. Ma, who earned his Ph.D. from the University of Cambridge in the UK, joined UConn in August 2011 following a two-year appointment as the J. Evans Attwell-Welch Postdoctoral Fellow at Rice University. He has a dual appointment in the Polymer Program at the Institute of Materials Science (IMS). He recently received the Distinguished Young Rheologist Award from TA Instruments, which recognizes young faculty members who show exceptional promise in the field of rheology. Prior to that, he received the National Science Foundation Early Concept Grant for Exploration Research (EAGER) award, which focuses on investigating the use of nanoparticles in the delivery of cancer drugs.
The Chemical & Biomolecular Engineering faculty invite you to our Innovation Connection networking event on Thursday, February 21st, from 3-6pm.
We invite alumni, entrepreneurs, and members of the industrial community to join our faculty in a casual environment that fosters collaboration and networking.
During this time, you will have the opportunity to learn about our ongoing research, tour our laboratories, network, discuss technology, and enjoy research posters.
Research talks will take place in the
Pratt & Whitney Engineering Building,
PWEB Room 150 (191 Auditorium Road, Storrs),
from 3-4 pm.
The networking and poster session will be held in the
UConn Foundation building (2390 Alumni Drive, Storrs),
from 4-6 pm.
In a recent Science journal article entitled “Strong, Light, Multifunctional Fibers of Carbon Nanotubes with Ultrahigh Conductivity,” Professor Anson Ma and colleagues from Rice University detail their recent breakthrough revolutionizing the use of carbon nanotubes. Carbon nanotubes (CNTs) are rolled cylinders of graphene sheets that have unprecedented mechanical, electrical, and thermal properties. In the past, many of the potential real-world applications of CNTs remained unfulfilled because researchers experienced great difficulties dispersing and processing CNTs into macroscopic objects while maintaining their fascinating properties. To address this problem, Dr. Ma and colleagues from Rice developed a scalable fluid-based process for spinning CNTs into lightweight and multifunctional fibers. These fibers combine the mechanical strength of carbon fibers with the specific electrical conductivity of metals, opening up the exciting possibility of using CNTs in aerospace, field-emission, and power-transmission applications. The article can be accessed at: https://www.science.org/doi/10.1126/science.1228061.
Dr. Ma, who earned his Ph.D. from the University of Cambridge in the UK, joined UConn in August 2011 as an Assistant Professor of Chemical Engineering with a dual appointment in the Institute of Materials Science Polymer Program. He recently received the Distinguished Young Rheologist Award from TA Instruments, which recognizes young faculty members who show exceptional promise in the field of rheology. Prior to that, he received the National Science Foundation Early Concept Grant for Exploration Research (EAGER) award, which focuses on investigating the use of nanoparticles in the delivery of cancer drugs.
For the second time in four years, a University of Connecticut student has won a prestigious Marshall Scholarship.
Ethan Butler, a 2012 chemical engineering graduate and past president of the UConn chapter of Engineers Without Borders, will spend the next two years in the United Kingdom pursuing his graduate studies at one, and possibly two, of Britain’s finest academic and research institutions.
A resident of Southbury, Conn. who grew up on a Christmas tree farm, Butler is one of 34 students in the United States to receive the highly-competitive scholarship this year. He is the third student in UConn’s history to be a Marshall Scholar. The others were Michelle Prairie in 2009 and Virginia DeJohn Anderson in 1976.
The Marshall Scholarship is Britain’s flagship government-funded program for American students who represent some of the finest and brightest college graduates in the United States. It is named after former Secretary of State George C. Marshall, and was established as a gesture of gratitude to the people of the United States for the assistance the U.S. provided after WWII under the Marshall Plan.
While in the U.K., Butler hopes to study advanced chemical engineering and innovation, entrepreneurship, and management at Imperial College London, one of the world’s top engineering and scientific universities known for the discovery of penicillin, the development of holography, and the foundation of fiber optics. His second choice is the University of Manchester, where physicist Ernest Rutherford ushered in the nuclear age and Professors Freddie Williams and Tom Kilburn developed the first programmable computer. He will find out his destination in the spring.
Butler’s long-term goal is to develop sustainable, community-based water and energy technologies in order to supply clean water and renewable energies to people in developing countries while simultaneously creating job opportunities for those in critical need.
“ UConn is a place where you have a lot of opportunities. If you shoot for the stars, you get the support of this massive university behind you.â€
“It’s all kind of surreal,†says Butler, who was notified of the honor a few days ago. “If you were to ask me four years ago if I’d get something like this, I would have said it was completely outside the realm of possibility … I’m just thrilled. The unimaginable has already happened. I’m just hoping to continue that upward trajectory.â€
Butler maintained outstanding academic scholarship during his four years at UConn. A member of the Honors Program, he was named a University Scholar – UConn’s highest academic honor – in 2012, and was inducted into the University’s most prestigious leadership program, the Legacy Leadership Experience, the same year. In 2011, Butler received UConn’s Global Citizenship Award along with a Udall Scholarship, National Collegiate Honors Council Portz Fellowship, and Newman Civic Fellows award. He was a member of EcoHuskies, UConn’s Environmental Policy Advisory Committee, and Tau Beta Pi, the engineering honors society.
But it was Butler’s involvement in the UConn Chapter of Engineers Without Borders that will always stand out as a large part of his UConn legacy. When Butler arrived in Storrs as a freshman in 2008, the chapter had little support and only a handful of members. Butler quickly got to work restructuring the group, organizing events, filing paperwork, and raising funds. As chapter president, Butler helped develop field projects in Nicaragua and Ethiopia, succeeded in raising more than $70,000, expanded the group’s membership to more than 40, and established a strong international support network of more than 50 non-profits, NGO’s, and government, academic, and business professionals.
“Building Engineers Without Borders, USA-UConn was a personally transformative experience for me,†Butler said in his scholarship application. “Not only did it call me to leadership, but also it exposed me to extreme poverty for the first time when I visited our partner-community in Nicaragua: La Prusia.â€
During his first trip to Nicaragua, Butler said he went door-to-door speaking with residents living in the extremely difficult conditions. He saw how the community’s access to markets, jobs, schools, and other services was severely restricted due to the heavy flooding and erosion of a local road to nearby Granada. UConn’s chapter of Engineers Without Borders is currently working on rebuilding the mile-long road, a project that Butler hopes will be completed within the next two years.
In order to repair the road, Butler and his engineering team developed a novel soil stabilization technique and used a low-impact design to create an economical solution for La Prusia. During his work with Engineers Without Borders, Butler also founded the Humanitarian Water Purification Lab Group, which is dedicated to advancing sustainable water purification technologies for developing countries and emergency relief. Water purification technology is an area in which Butler has some experience. For his senior engineering capstone project, Butler designed and evaluated a water purification system for Bangladeshi waters contaminated with arsenic.
“Ethan made an indelible mark here as an innovator, researcher, and advocate for sustainable engineering solutions to some of the world’s most pressing environmental problems,†UConn President Susan Herbst wrote in a letter of endorsement submitted with Butler’s scholarship application. “Not only did he demonstrate the intellect and drive to master the scientific and technical knowledge he needed, but also he proved a remarkable leader, bringing together faculty, entrepreneurs, students, and community stakeholders to launch several international projects still ongoing today … He is fiercely smart, thoughtful, and pragmatic – a combination designed to make a tangible difference.â€
Butler says he is grateful for the enormous support he received from the University throughout his four years in Storrs. Nowhere was that more evident than in the final days of the Marshall Scholarship process, when Butler had to fight through an early season winter snowstorm to attend his practice interview. Stuck in Storrs after the storm, Butler stayed at the home of Vice Provost for Academic Affairs Sally Reis overnight to be sure he made it to Massachusetts the next day. Other individuals who braved foul weather or opened up their homes to help Butler through the application process include former Associate Vice Provost and Honors Program Director Lynne Goodstein, history professor Christopher Clark (chair of the scholarship nominating committee), Ecology and Evolutionary Biology Associate Professor Elizabeth Jockusch, and Chemical, Materials, and Biomolecular Engineering professor C. Barry Carter. Jeffrey McCutcheon, Northeast Utilities Assistant Professor of Environmental Engineering, served as Butler’s academic mentor.
“I am deeply grateful for all the support I received from the University,†says Butler, whose mother is a UConn alum. “UConn is a place where you have a lot of opportunities. If you shoot for the stars, you get the support of this massive university behind you. I was able to do things I never imagined I would do.â€
Jill Deans, director of UConn’s Office of National Scholarships, says Butler exemplifies the best UConn has to offer and does so with humility and grace.
“UConn students have both the drive and the intellect to be national leaders in their fields,†Deans says. “Many, like Ethan, are also deeply humble. I am delighted that these qualities are being recognized in premier competitions like the Marshall. I’m excited to see what the future holds for Ethan. His aspirations are indistinguishable from the common good, and his talents are vast. This award will indeed help him maximize his potential to solve some of the most pressing social and environmental issues of our age.â€
Butler expects to begin his graduation experience overseas in fall 2013.
