Daytime passive radiative cooling is an effective way to reduce energy consumption for building cooling. However, overcooling might occur in radiative cooling at low-temperature which presents limitations in thermal management. Herein, a new SiO2/poly(vinyl alcohol) composite aerogel with nanomicro–multistage porous structure for thermal insulation and radiative cooling was fabricated by a non-solvent-assisted freeze-drying strategy. In the fabrication process, the nonsolvent (acetone) for poly(vinyl alcohol) was utilized to control the proportion and size of the macro-porous structure inside the SiO2/poly(vinyl alcohol) composite aerogel, making the thermal conductivity of the aerogel decreased to 0.0390 W/mK while spontaneously increasing its solar reflectance and infrared (8–13 μm) emissivity to 93.70% and 98.19%, respectively. The composite aerogel achieved sub-ambient cooling of up to 14.1 °C during the day and above-ambient warming of 3.8 °C at night, avoiding nighttime overcooling. The SiO2/poly(vinyl alcohol) composite aerogel demonstrates adaptive thermal management compared to commercial insulation materials, making it suitable for intelligent thermal management of energy-saving buildings.
No takes yet. Share an insight, caveat, or question.
Ma et al. (2024) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: