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Crack-Resistant and Self-Healable Passive Radiative Cooling Silicone Compounds
Cong Guo1, Chuanlong Li1, Zeshuang Qiao1
1College of Polymer Science and Engineering, National Key Laboratory of Advanced Polymer Materials, Sichuan University, Chengdu, 610065, China.
Advanced Materials (Deerfield Beach, Fla.)
|February 28, 2025
Summary
This study introduces a self-healing, crack-resistant radiative cooling material. It autonomously repairs cracks, restoring cooling performance and enhancing durability for outdoor applications.
Area of Science:
- Materials Science
- Nanotechnology
- Thermodynamics
Background:
- Outdoor materials, especially for passive radiative cooling, suffer from crack damage, impairing sunlight scattering and heat emission.
- Sunlight absorption or transmission through cracks degrades the efficiency of cooling systems.
- Existing materials lack robust crack resistance and self-healing capabilities for prolonged outdoor use.
Purpose of the Study:
- To develop a novel silicone/dielectric radiative cooling compound with self-healing and crack-resistant properties.
- To enhance the durability and functionality of passive radiative cooling systems under environmental stress.
- To investigate the mechanism of self-healing and crack resistance in a dynamic hydrogen bond network.
Main Methods:
- Synthesis of a silicone polymer with UV-vis-NIR transparent hydrogen bond moieties and boron nitride (BN) dielectrics.
- Fabrication of a dynamic polymer/dielectric hydrogen bond network incorporating BN as sunlight scatterers and hydrogen bond acceptors.
- Characterization of crack healing efficiency, fracture energy, and cooling performance restoration.
- Analysis of polymer chain mobility and hydrogen bond re-association for self-healing mechanism.
Main Results:
- The developed compound exhibits autonomous self-healing of cracks ranging from micrometers to millimeters wide.
- Cooling performance is restored to approximately 100% after self-healing.
- Fracture energy is enhanced by 865% due to the combination of rigid BN and sacrificial hydrogen bonds, preventing crack propagation.
- The material demonstrates autonomous crack blunting and deflection under stress.
Conclusions:
- The novel silicone/dielectric compound offers superior self-healing and crack resistance for radiative cooling applications.
- The dynamic hydrogen bond network effectively restores material integrity and cooling function after damage.
- This material is highly suitable for demanding, long-term outdoor applications requiring robust performance.
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