Switchable Cavitation in Silicone Coatings for Energy‐Saving Cooling and Heating. Issue 29 (5th June 2020) - Zhao, Huaixia
Abstract: Space cooling and heating currently result in huge amounts of energy consumption and various environmental problems. Herein, a switching strategy is described for efficient energy‐saving cooling and heating based on the dynamic cavitation of silicone coatings that can be reversibly and continuously tuned from a highly porous state to a transparent solid. In the porous state, the coatings can achieve efficient solar reflection (93%) and long‐wave infrared emission (94%) to induce a subambient temperature drop of about 5 °C in hot weather (≈35 °C). In the transparent solid state, the coatings allow active sunlight permeation (95%) to induce solar heating to raise the ambient temperature from 10 to 28 °C in cold weather. The coatings are made from commercially available, cheap materials via a facile, environmentally friendly method, and are durable, reversible, and patternable. They can be applied immediately to various existed objects including rigid substrates. Abstract : Silicone coatings that can be switched between radiative cooling and solar heating state are reported. The switching mechanism is based on mechanocontrolled dynamic cavities. In the cavity‐open state, the coatings exhibit 93% solar reflection with 94% infrared emission for cooling, while in the cavity‐closed state, they show 95% solar absorption for heating.