Developing guidelines for identifying bio-friendly materials to combat the cold

By David Staudacher

Researchers in mechanical and industrial engineering at the University of Illinois Chicago have outlined a design framework for identifying materials out of millions of available chemical compounds, which can thermally respond by trapping the latent heat released during water vapor condensation and thereby passively delaying the freezing of droplets under frigid temperature conditions.

These materials are substances that release or absorb a significant amount of energy during their phase transition to provide useful heating or cooling. Some common examples of phase change materials are water, chocolate and paraffin waxes. But not every such material can be used for delaying water drop freezing.

The researchers’ findings were published in the journal Advanced Functional Materials under the title “How to Select Phase Change Materials for Tuning Condensation and Frosting?” Rukmava Chatterjee, Umesh Chaudhari and Sushant Anand are the authors of the paper, and their submitted artwork is featured on the back cover. Vishek Masalia and Louie Zuniga contributed to the research.

“To develop the framework, we performed systematic studies to understand the water droplet interactions with various randomly selected phase change materials in the absence or presence of condensation,” said Anand, associate professor of mechanical and industrial engineering.

“These comprehensive investigations established the correlation between microscale heat transport phenomena and the resulting macroscopic effects as a function of the material’s interfacial and inherent thermomechanical properties.”

The research explains the fundamental mechanisms responsible for condensation-induced melting on a wide variety of phase change materials and demonstrates their versatile real-world applications.

“The coatings are capable of formulation-specific multifunctional properties: frost resistance under frigid conditions, thermoresponsive optical transparency and fast self-reparability,” he said.

The research has the potential to significantly impact industries such as thermal management, energy storage and ice-shedding technologies. By using readily available and environmentally safe chemicals, the freeze-protection system sets the groundwork for a greener and more sustainable future.

“The results are only a precursive indication of the vast potential of functionalities that can be brought into the realm of responsive materials,” Chatterjee said.

“PCMs hold tremendous potential toward a myriad of new applications, like the development of anti-freezing storages for vaccines, fog-dew harvesting systems, weather-tolerant wearable electronics and more. But controlling the supercooling and roughness of PCMs once they turn solid could be the key to getting the best performance out of them, so that is where we are focused next.”