By Amanda Campanaro, IMS
There’s a special moment for most students when they discover what they really want to do with their major. For Rebecca Quardokus, Assistant Professor in Chemistry and associate faculty in IMS, that moment came as a junior at Grand Valley State University, Michigan, when her father sent her an article on Professor James Tour’s research at Rice University, Texas.
Dr. Quardokus, who had recently become a chemistry major, found the research fascinating. “His group had synthesized nano-sized cars with C60 fullerenes (buckyballs) for wheels, and they used scanning tunneling microscopy (STM) to image individual cars moving around on a gold surface,” Dr. Quardokus explains. “I was very excited to learn that STM, in addition to imaging, could manipulate individual atoms and molecules on the surface.” It was then she decided to attend graduate school to work with and master that “amazing technique.”
Now, Dr. Quardokus focuses her research on the engineering and reliability of molecular networks and two-dimensional materials for next-generation electronic devices. Her passion for learning STM has led her to begin a project working on developing new two-dimensional materials using surface-confined polymerization reactions.
“I use scanning tunneling microscopy, with its ability to measure individual atoms and molecules, to study the reactants and products,” she says. “I will also study the charge and thermal transport properties of these materials.” Her group is hoping to tune specific properties for use in next-generation electronics.
Additionally, she is working on building a scanning tunneling microscope of her own. “Ultimately, I would like to build a multi-probe STM inside of a scanning electron microscope in order to analyze the reliability and functionality of nano-devices under operational conditions.”
Dr. Quardokus was always interested in math and science, and she entered college as a pre-dentistry major. However, after completing a summer of chemistry research at Grand Valley, she realized she preferred research, and decided to pursue a Ph.D. instead.
“During my graduate research at the University of Notre Dame under the direction of Dr. Alex Kandel, I used low-temperature ultra-high-vacuum scanning tunneling microscopy to study large mixed-valence iron-based inorganic molecules on gold surfaces,” she explains. “Mixed-valence compounds have interesting intramolecular charge-transfer properties.”
They found that the intramolecular charge-transfer rates depend on the geometry of the organic linker between the metal centers, and that these mixed-valence compounds retain their electronic properties when placed on a metal surface in the absence of bulk solvent.
“We also found that ferrocenecarboxylic acid forms hydrogen-bonded dimers and pentamers with longer range two-dimensional quasicrystalline ordering,” she says. This was the first example of a small molecule self-assembling into a quasicrystalline structure.
More recently, Dr. Quardokus was a National Research Council Postdoctoral Fellow at the National Institute of Standards and Technology in Boulder, Colorado. With Frank DelRio as her postdoctoral advisor, her project involved studying the electronic properties of silicon nanowires and two-dimensional materials. “I used a four-probe scanning tunneling microscope to measure the electronic properties and surface characteristics of positively and negatively doped silicon nanowires,” she says.
Dr. Quardokus joined UConn’s Chemistry Department and IMS in 2016 because she believes UConn has a very strong reputation as an undergraduate teaching institution and is a world-class research institution. “I love having the opportunity to collaborate with leading scientists, and I value teaching and education because many influential professors and teachers played a large role in my personal path to success,” she says. This was very important to Dr. Quardokus, who says she had many amazing teachers and professors throughout her educational career. “They were instrumental in shaping my career path and helping me shape and achieve my goals.”
As for her teaching style, Dr. Quardokus prefers an interactive classroom. “I want students to be thinking about and discussing problems in class. I try to show the students real-world applications for the chemistry that we’re talking about,” she explains. She hopes that students are able to internalize the concepts and use the information and problem-solving skills to tackle new challenges in the field. “I think that students positively affect research. They have a fresh perspective and ask really good questions that help push back the frontiers of science.”
Dr. Quardokus is currently recruiting graduate students to accept in Fall 2017, and she is excited to share her research program with the incoming students. “I will be installing a new low-temperature ultra-high-vacuum scanning tunneling microscope and atomic force microscope this summer,” she says. The instrument will have the capabilities to image individual atoms, molecules, and molecular bonds. “I am excited to teach students how to operate this state-of-the-art equipment allowing them to do research at the forefront of the scientific frontier.”
Among her awards are the National Research Council Postdoctoral Fellowship, 2014-2016, the Rohm and Haas Outstanding Graduate Student Award, 2013, an NSF GK-12 Graduate Fellowship, 2009-2011 and a Nieuwland Graduate Fellowship in 2007.