(4v) Energy-Efficient Alternatives for Sustainable Polymer Processing

1. Research Interests

The goal of my research is to come up with sustainable, environment-friendly solutions to support the growing material and energy demands of the world. Over the course of my research career, I have worked on interdisciplinary projects focused on developing sustainable polymer processing methodologies and helping bridge the gap between academia and industry. My primary areas of interest are additive manufacturing of high-performance nanocomposites, out-of-oven processing of carbon-based composites, and structure-property relationships of recyclable, bio-inspired structures. The projects I plan on undertaking as an independent researcher lie at the interface of several scientific disciplines including chemical engineering, polymer science, solid mechanics, and electrical engineering, with applications ranging from biomedical prosthetics to hypersonic jets. My previous and current research experiences are presented below, along with a concise overview on future directions I wish to pursue and a list of selected publications I have authored.

• Previous Research:

As a Ph.D. student at Texas A&M University, I worked with Prof. Micah J. Green on rapid processing of thermosets using electromagnetic (EM) fields. Conductive materials such as carbon fibers and carbon nanotubes rapidly heat up when exposed to such fields: my PhD research involved leveraging this phenomenon for out-of-oven additive manufacturing, repair, and recycling of high-performance thermosets dispersed with conductive materials. EM heating is volumetric and rapid, thereby allowing for a sustainable alternative to energy-intensive convective ovens. The work I conducted in Prof. Green’s lab attracted industrial and DOD attention as well as funding (NAVAIR, Honeywell, KCNSC), eventually leading to the filing of three U.S. patents. I had the opportunity to mentor over ten graduate and undergraduate students during my PhD and was also awarded the Best PhD Thesis award by the Chemical Engineering department, Texas A&M University in 2023.

• Current Research:

I am currently working as a Postdoctoral Associate in Prof. Christopher J. Ellison’s lab at the University of Minnesota. I am part of a multi-institutional interdisciplinary project funded by DOE which is focused on developing sustainable upcycling methodologies to reduce the carbon footprint of thermoplastics on the environment. While mechanical recycling is commonly used for industrial-scale waste plastic management, it cannot be used beyond a certain number of cycles and is not effective when a waste stream has a mixture of melt-immiscible polymers. My project involves the development of a chemical recycling methodology that can selectively depolymerize waste plastics back to their monomers, and further design a reactive melt-processing setup to scale up this process to facilitate industrial-scale sustainable chemical recycling.

• Future Directions:

Using my experience in polymer processing and advanced manufacturing, I aim to establish a research group that transcends conventional boundaries, harnessing the synergy of experimental and computational power to design sustainable pathways to fabricate high-performance materials.

My journey as a principal investigator will involve developing sustainable, energy-efficient alternatives for processing of high-performance composites. One direction I am interested in involves the use of electromagnetic fields to concurrently align nanofillers and induce electrothermal heating to fabricate aligned nanocomposites with tailored, anisotropic dielectric properties. Another pathway I plan on pursuing is the use of lasers to fabricate high-density carbon-carbon composites, potentially alleviating the dependance on energy-inefficient ovens and autoclaves currently used to produce such materials. Further, I also want to explore the use of covalent adaptive networks (CANs) to fabricate recyclable prosthetics; while CANs suffer from mechanical creep over prolonged periods of use, addition of stiff fillers or selectively suppressing bond rearrangement can help produce CANs with enhanced mechanical properties.

2. Teaching Interest:

As a PhD student at Texas A&M University, I served as a teaching assistant (TA) for courses such as Numerical Analysis for Chemical Engineers, Kinetics and Reactor Design, and Polymer Engineering. My opportunities as a TA included conducting weekly office hours, designing coursework and assignments, grading submissions, and teaching special topics relevant to the course material. To further enhance my teaching abilities, I actively participated in the workshops offered by the Center for Teaching Excellence at TAMU. My teaching interest lies within the domain of chemical engineering, mathematics, and material science and engineering, including (but not limited to) courses such as Principles of Chemical Engineering, Thermodynamics, Heat Transfer, Mass Transfer, Transport Phenomena, Kinetics and Reaction Engineering, Introduction to Materials Science, Solid Mechanics, Fluid Mechanics, and Process Analysis. Overall, I am confident to say that I am a patient, hard-working, and rational instructor. I try to engage my students and present them with the concepts in a manner such that they can appreciate the real-life applications. I firmly believe that success as an instructor depends on whether the students end up being motivated to think critically about any new concept. I enjoy and love to teach and am always looking for new and more innovative ways of challenging my students to think outside the box.

3. Selected Publications and Patents:

• Electrothermal free-form additive manufacturing of thermosets. A. Sarmah, E. M. Harkin, T. Q. Tran, M. J. Cupich, M. J. Green. Additive Manufacturing, 2024.

• Additive manufacturing of nanotube-loaded thermosets via direct ink writing and radio-frequency heating and curing. A. Sarmah, S. K. Desai, A. G. Crowley, G. C. Zolton, G. B. Tezel, E. M. Harkin, T. Q. Tran, K. Arole, M. J. Green. Carbon, 2022.

• Rapid Manufacturing via Selective Radio-Frequency Heating and Curing of Thermosetting Resins. A. Sarmah, S. K. Desai, G. B. Tezel, A. Vashisth, M. M. Mustafa, K. Arole, A.G. Crowley, M. J. Green. Advanced Engineering Materials, 2022.

• Interfacial carbon fiber–matrix interactions in thermosetting composites volumetrically cured by electromagnetic fields. A. Sarmah, M. A. Morales, A. Srivastava, S. Upama, A. Nandi, T. C. Henry, M. J. Green, A. Vashisth. Composites Part A: Applied Science and Manufacturing, 2023.

• Recycle and Reuse of Continuous Carbon Fibers from Thermoset Composites Using Joule Heating. A. Sarmah, S. Sarikaya, J. Thiem, S. Upama, A. N. Khalfaoui, S. S. Dasari, K. Arole, S. A. Hawkins, M. Naraghi, A. Vashisth, M. J. Green. ChemSusChem, 2022.

• Competing Effects of Radio Frequency Fields on Carbon Nanotube/Resin Systems: Alignment versus Heating. A. Sarmah, R. D. Mee, K. Arole, D. Chi, E. M. Harkin, S. S. Dasari, A. J. K. Wright, T. Q. Tran, A. Rout, M. J. Green. Macromolecular Materials and Engineering, 2023.

• Patch repair of composites using Dielectric Barrier Discharge-induced heating and curing. A. Sarmah, S. S. Dasari, N. Nagabandi, D. G. Carey, S. A. Micci-Barreca, A. Vashisth, M. J. Green. Applied Materials Today, 2023.

• In situ investigation of the rheological and dielectric properties of a cross-linking carbon nanotube-thermosetting epoxy. A. Sarmah, P. Z. Ramos, M. J. Green, J. J. Richards. Soft Matter, 2023.

• Additive manufacturing of thermosetting resins via direct ink writing and radio frequency heating and curing. A. Sarmah, A. Crowley, S. Desai, G. Zolton, M. J. Green. US Patent Application, Pending.

• Method for repairing composite materials via Dielectric Barrier Discharge. A. Sarmah, S. S. Dasari, D. Carey, N. Nagabandi, M. J. Green. US Patent Application, Pending.

• Free-form fabrication of continuous carbon fiber composites using electric fields. S.S. Dasari, A. Sarmah, A. J. K. Wright, D. Carey, N. Nagabandi, M. J. Green. US Patent Application, Pending.