China develops cement that can cool itself by scattering heat

Researchers from Southeast University in China have developed a novel "supercool" cement that significantly reduces surface temperature by scattering sunlight rather than absorbing it. This cement, engineered with metasurfaces and a photonic architecture, achieves a high solar reflectance of 96.2% and an emissivity of 96% in the mid-infrared spectrum, enabling it to cool itself by radiative heat dissipation. Performance tests demonstrated the material’s robustness against mechanical stresses, abrasive forces, and harsh environmental conditions such as UV radiation, corrosive liquids, and freeze-thaw cycles. The cement also maintains plasticity for complex shapes and amphiphobic properties, making it versatile for structural applications in roofs and walls. The researchers adjusted the chemical composition of clinker particles to promote the self-assembly of reflective ettringite crystals and hierarchical pores, enhancing sunlight scattering and heat emission. Real-world testing on building roofs showed that the supercool cement could reduce surface temperatures by up to 9.72°F (5.