New UMass Research Describes Porous Carbon Networks’ Potential Use in Energy Storage, Wound Healing, and Other Applications
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In a new article published in the journal Advanced Functional Materials, a team of researchers from the College of Natural Science’s Department of Polymer Science and Engineering (PSE)—including Reika Katsumata, Assistant Professor of Polymer Science and Engineering, and James Pagaduan, a recent PhD graduate co-advised with Todd Emrick of the Center for Bioactive Delivery—highlighted the potential of porous heteroatom-doped carbon networks for energy-storage and wound-healing applications. Furthermore, a continuous bottom-up technique that the research team refers to as “freeze-burn” could advance the frontiers of functional porous material synthesis for other important applications.
This research introduces a simple and scalable strategy for producing porous carbon structures using low-cost chemical compounds with rapid thermal annealing (RTA), a procedure that is currently employed in the manufacture of semiconductors. RTA enables heating rates as fast as 150°C/s and the easy switching of gas environments. The researchers leveraged these processes to cut down the energy and time requirement for carbon formation from a polyacrylonitrile-based polymer blend system—from several hours down to as fast as 20 minutes.
The term “freeze-burn” highlights the two major stages of annealing (treating substances by means of heat). The first stage involves the freezing or fixing of the structure by simultaneous phase separation and thermal crosslinking at 300°C in air. Subsequent burning, including pyrolysis and degradation of non-carbonizable components, is then activated by increasing the temperature to above 600°C in a nitrogen atmosphere. Extrinsic doping can also be achieved by the addition of a boron-containing compound to the precursor formulation to enhance the materials performance. This RTA-based method reconciles the tradeoffs among rigorous polymer synthesis, dopant incorporation, structural control, and procedural simplicity.
PSE researchers envision two immediate applications for porous heteroatom-doped carbon networks using polymer-assisted RTA:
- Energy Storage. Freeze-burned samples can be fabricated directly on stainless steel, which acts as the current collector, for in situ preparation of high-performance supercapacitors without any post-processing procedure. This research is being conducted in collaboration with Watkins Research Group at PSE.
- Wound Healing. PSE also demonstrated that boron doping improved the in vitro proliferation and migration of fibroblasts and keratinocytes—the most abundant cell types in the dermal and epidermal layers of skin—on freeze-burned samples, which could prove useful in wound healing. This research is being conducted in collaboration with the Department of Biomedical Engineering’s KearneyLab.
This work was borne out of a chance encounter between Reika Katsumata and James Pagaduan, after both attended a UMass talk by astronaut and PSE alum Cady Coleman. The two shared a deep interest in space, where thermal superinsulation is essential for any activity. But materials that are being shipped to space must be light, and preferably quick to assemble. Katsumata and Pagaduan began to consider how RTA could be applied to polymer sciences to find solutions not only for thermal superinsulation, but also for myriad other uses.
Pagaduan recalled, “I was tasked by Reika to set up the RTA instrument in the Katsumata lab. She then challenged me to exploit RTA to fabricate aerogels in a simple, energy-efficient manner using commercially available polymers. Over the years, I realized that science is indeed an incremental effort. Since I was starting from scratch, creating aerogels—which can be 3D-printed to achieve a combination of outstanding properties relevant to diverse applications, such as thermal superinsulation—I was a little ambitious. I decided to generate porous carbon films instead. The initial efforts led to the conception of freeze-burn 1.0, which was first published in ACS Applied Polymer Materials. This top-down approach involving carbon fillers, templated by a degradable polymer blend, spurred the development of freeze-burn 2.0 (this work) employing polymers as both the template and carbon precursor. I believe that this body of work serves as a strong foundation for potential aerogel synthesis using polymer-assisted RTA.”
As UMass researchers continue their work on the technique, they are looking to advance the frontiers of functional porous-material synthesis for applications spanning membrane technology, catalysis, bioengineering, energy damping, and thermal superinsulation.
"We pioneer to convert soft polymer blends to hard materials in a time- and energy-efficient manner,” Katsumata contends. “As polymer structures are readily tailorable, we envision that freeze-burn has overwhelming potential to fabricate functional hard materials, including metals, carbonaceous materials, and ceramics."