Researchers have engineered a material that combines extreme thermal insulation with exceptional stiffness, achieving a thermal conductivity profile of approximately 0.04 W m-1 K-1 at room temperature, according to a study published in Science Advances. Developed by a multidisciplinary team including researchers from North Carolina State University, the University of North Carolina at Chapel Hill, and Nanjing Normal University, this dense thin-film semiconductor approaches the theoretical limits of thermal insulation while remaining 700 to 10,000 times stiffer than silicone.
Molecular Engineering of Layered Perovskites
The breakthrough relies on a specific class of materials known as two-dimensional hybrid organic-inorganic perovskites. These materials feature alternating organic and inorganic layers structured in a highly-ordered crystalline thin film. According to Dali Sun, a professor of physics at North Carolina State University and co-corresponding author of the study, combining stiffness and thermal insulation is a significant challenge because rigid materials typically conduct heat easily, while soft materials insulate against it.
To overcome this limitation, the research team used advanced molecular engineering. They replaced specific carbon-carbon chains within the organic layers with a tailored combination of benzene rings, creating an azobenzene ethyl ammonium lead iodine thin film. Jun Liu, an associate professor of mechanical and aerospace engineering at NC State and co-corresponding author, explains that this intentional structural modification allows scientists to precisely control both mechanical stiffness and thermal conductivity at a molecular level.
Performance and Scalability Compared to Silicone
When tested at room temperature, the newly synthesized hybrid material demonstrated a thermal conductivity of roughly 0.04 W m-1 K-1. This performance is five times lower than silicone, a traditional heat insulator commonly used in products like oven mitts, which has a thermal conductivity of 0.2 W m-1 K-1. Furthermore, the hybrid thin film achieves this superior thermal performance while maintaining a stiffness that exceeds silicone by several orders of magnitude.
Beyond its physical properties, the production method developed by the research team is designed for scalability. According to Liu, the manufacturing process allows the material to be produced easily at large scales and applied directly as a coating.
Applications Across Multiple High-Tech Industries
The unique combination of rigidity and low thermal conductivity opens up substantial utility across diverse industries, according to Sun. Potential use cases span from cookware and electronic devices to space travel. By demonstrating that molecular engineering can fine-tune hybrid layered materials, the research establishes a foundation for developing novel thermal protection solutions where space, weight, and structural integrity are critical.
The research paper, titled “Extremely Low Thermal Conductivity in Rigid Layered Hybrid Perovskites,” was co-authored by Ziqi Wang, Ankit Negi, Liang Yan, and Qingxuan Wang as co-lead authors. Additional corresponding authors include Wei You of UNC Chapel Hill and Jun Zhou of Nanjing Normal University. Department of Energy.
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