Engineers have created a new smart material that promises to improve energy efficiency for cooling indoor spaces. This innovative thermochromic polymer blend is not only more affordable than current options but also boasts an estimated lifespan of 60 years.
Researchers at Rice University have introduced a smart material capable of altering its transparency based on temperature changes. This new polymer outperforms existing materials in durability, transparency, and responsiveness, according to a recent study published in Joule. The findings suggest that this polymer blend could greatly improve energy efficiency for indoor cooling.
Staying cool can be crucial, yet air conditioning already contributes to 7% of global energy consumption and 3% of carbon emissions. With record high temperatures and frequent heatwaves becoming the norm, finding efficient methods to maintain comfortable indoor conditions is more critical than ever.
One potential solution involves applying coatings to windows that block heat while still allowing light to pass. Thermochromic materials are part of this solution, but currently available options are often too costly and have short lifespans, making them impractical for use in buildings, vehicles, and other applications.
The newly developed salted polymer blend system from Rice University’s Nanomaterials Laboratory, led by Pulickel Ajayan, addresses these issues, paving the way for wide-scale adoption of thermochromic technology for energy-efficient indoor climate control.
“Imagine windows that become less transparent as the temperature rises, helping to keep interiors cool without extra energy consumption,” explained Sreehari Saju, a doctoral student in materials science and nanoengineering at Rice, who co-authored the study. “Our formulation combines organic and inorganic materials to tackle the existing thermochromic materials’ challenges, such as their high costs and limited life spans.”
“Additionally, this material’s thermal response aligns well with real-world environmental conditions. We believe that smart windows made with this material could drastically cut energy usage in buildings, positively impacting both energy expenses and carbon emissions.”
The research team utilized both experimental techniques and computer simulations to evaluate how the material performs under various environmental and structural conditions. They specifically looked at how it would function in different urban settings globally to gauge its potential large-scale impact.
“Our method was distinct because it required a balanced combination of materials and techniques that had not been previously explored together, paving the way for new smart material development,” noted Anand Puthirath, a research scientist in the Ajayan group and co-author of the study. “We conducted extensive experiments to assess the properties, stability, and durability of the material, demonstrating that our blend surpasses current thermochromics.”
The team created the material by blending two polymers with a specific type of salt, refining the composition to ensure smooth transitions between transparent and opaque states with temperature fluctuations. Their results reveal that this new thermochromic blend is not only effective in managing solar radiation but also incredibly long-lasting, with an estimated lifespan of 60 years.
“This research sets new standards for durability and performance in thermochromics, particularly within a practical, simple system,” said Ajayan, the study’s lead author and Rice’s Benjamin M. and Mary Greenwood Anderson Professor of Engineering, as well as the department chair of materials science and nanoengineering. “Our work tackles a significant challenge in sustainable architecture, providing a feasible and scalable solution for improving energy efficiency in buildings.”
The study of the thermochromic properties of this material was conducted in collaboration with Professor Yi Long and her doctoral student, Shancheng Wang, from the Department of Electronic Engineering at the Chinese University of Hong Kong, Sha Tin.
