Switchable Cavitation in Silicone Coatings for Energy‐Saving Cooling and Heating

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.

Photothermal Devices for Sustainable Uses Beyond Desalination

“…Zhao et al developed a bilayer silicone coating consisting a switchable light‐transmitting layer and a photothermal carbon black‐embedded layer. [ 146 ] When scratched or stretched, the switchable light‐transmitting layer became opaque due to the formation of cavities in the PDMS matrix. It could achieve efficient solar reflection (93%) and long‐wave infrared emission (94%) to bring a temperature drop.…”

Prevent or Cure—The Unprecedented Need for Self‐Reporting Materials

“…Especially in the context of energy saving and solar modulation, thermo‐responsive materials are of key interest. [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ] Heating and cooling systems in any vehicle, storage place, or indoor space require high amounts of energy, cause environmental problems (toxic cooling substances, pollution)[ 71 , 72 ] or may result in health issues (dry skin, headaches, colds). [ 73 , 74 ] Therefore, smart thermo‐responsive glazing systems along window coatings have been developed.…”

“…Similar phase transitions from transparent to translucent (or vice versa) were obtained in liquid‐crystal siloxane polymers, [66] polyacrylamide hydrogels,[ 67 , 68 ] nanoparticle–polymer composites, [69] or dynamic porous silicon films. [70] Clearly, these materials are promising for future developments of smart, thermo‐responsive systems for solar control coatings and windows, displays, or sensors with tunable thermal and optical properties.…”

Vorbeugen oder Heilen – die beispiellose Notwendigkeit von selbstberichtenden Materialien

“…[61] Vorallem im Zusammenhang mit Energieeinsparung und Solarmodulation sind thermoresponsive Materialien von zentralem Interesse. [63][64][65][66][67][68][69][70] Heiz-und Kühlsysteme in jedem Fahrzeug,L agerort oder Innenraum bençtigen hohe Energiemengen, verursachen Umweltprobleme (toxische Kühlmittel, Verschmutzung) [71,72] oder verursachen eventuell Gesundheitsprobleme (trockene Haut, Kopfschmerzen, Erkältung). [73,74] Ausd iesem Grund wurden intelligente thermoresponsive Verglasungssysteme und Fensterbeschichtungen entwickelt.…”

“…¾hnliche Phasenübergänge von transparent zu transluzent (oder umgekehrt) wurden in flüssigkristallinen Siloxanpolymeren, [66] Polyacrylamid-Hydrogelen, [67,68] Nanopartikel-Polymer-Verbundstoffen [69] oder dynamischen porçsen Siliciumfilmen erzielt. [70] Somit sind diese Materialien sicherlich nützlich fürz ukünftige Entwicklungen intelligenter,t hermoresponsiver Systeme fürS onnenschutzbeschichtungen und Fenster,D isplays oder Sensoren mit einstellbaren thermischen und optischen Eigenschaften.…”