Nano@Tech Fall 2022 Series | Thermally Responsive Materials for Clean Water and Energy

Thermally Responsive Materials for Clean Water and Energy
Featuring Akanksha Menon | School of Mechanical Engineering, Georgia Tech

Abstract: The global demand for energy and water is projected to increase by 40% and 55%, respectively, by 2050. Meeting these targets in an efficient, affordable, and sustainable manner necessitates significant scientific and technological advances. The inherent challenge lies in the complexity of water-energy systems due to interactions that span multiple length- and timescales, and this is where leveraging advances in materials provides an opportunity to make them more efficient. This talk will focus on functional materials that are thermally responsive – ranging from ionic liquids to inorganic salt hydrates, and semiconducting polymers – to enable low energy chemical separations (clean water) and to decarbonize heat (clean energy). Ionic liquids combine high ionic strength and affinity for water owing to hydrophilic functional groups, while hydrophobic moieties impart a critical temperature above which these materials release water. The novelty of these materials is that the enthalpy of separation is approximately three orders of magnitude lower than conventional liquid-vapor thermal separations that vaporize water, and the critical temperature can be achieve using solar energy. Another set of materials that are thermally responsive are salt hydrates that can undergo reversible thermochemical reactions to store and release energy in the form of heat. To mitigate stability challenges associated with volumetric changes accompanying the thermochemical reaction, an inorganic-organic composite material is designed by encapsulating the salt into a hydrogel matrix. The novelty of the approach is that it creates a highly porous matrix around the particles to achieve a form-stable composite for a highly reversible thermal battery unlike conventional approaches of impregnating the salt into a porous matrix. The last class of materials that will be highlighted are semiconducting polymers for direct conversion of heat into electricity via the thermoelectric effect. The flexible nature of the polymer and the use of solution-processing techniques opens new avenues for wearable electronics that harvest body heat or provide personal cooling to lower energy demands. These examples demonstrate the potential of dynamic and responsive materials to modulate heat and mass transport for the next generation energy and water systems.

Bio: Akanksha Menon is an assistant professor in the Woodruff School of Mechanical Engineering at Georgia Tech. She also directs the Water-Energy Research Lab. Prior to this, she was an ITRI-Rosenfeld Postdoctoral Fellow in the Energy Technologies Area at Lawrence Berkeley National Lab, where she continues to be a research affiliate. Her research focuses on applying thermal science/engineering and functional materials to develop sustainable technologies for the water-energy nexus. Examples include solar desalination for a circular water economy, thermal energy storage for decarbonizing heat, and carbon-negative building materials. Menon received a Ph.D. in mechanical engineering from Georgia Tech, where she developed polymer-based thermoelectric materials and devices for energy harvesting and personal thermoregulation. She is a recipient of the 2019 Sigma Xi Dissertation Award and the 2017 Materials Research Society (MRS) Silver Award. She was also recognized in the 2020 Falling Walls Breakthroughs of the Year: Emerging Talents category, and she was featured by the U.S. Department of Energy in their Women @ Energy initiative. Menon is in the Class of 1969 Teaching Fellows cohort, and currently serves as the faculty adviser for Pi Tau Sigma, the mechanical engineering honor society.

A boxed lunch will be served on a first come, first served basis.

Watch a live-stream of the seminar at