New contributions to passive daytime radiative cooling
A recently published study presents volourfully coated cotton fabric for passive daytime radiative cooling.
Passive daytime radiative cooling (PDRC), which can cool objects without energy consumption, is a promising strategy for realizing sustainable cooling. However, developing radiative cooling materials with esthetic versatilities is still a great challenge, let alone colourful fabrics with cooling properties. Researches have now fabricated a coloured radiative cooling cotton fabric by using a facile and scalable spraying strategy. Randomly distributed silane modified SiO2 serves as the backscattering underlayer exhibiting both high solar reflection and broadband mid-infrared emission.
Temperature drop of 5.6 °C
Acrylate polymers used to encapsulate pigments improve the pigment adhesion without sacrificing their spectral properties, and the encapsulated pigments cover on the underlayer as a coloured layer to generate specific color. Consequently, the coloured coated cotton fabric achieves a relatively high near infrared reflectance of 89 % and an atmospheric window emissivity of 91 %. Cooling effects are achieved by the colored coated cotton fabrics, which yield temperature drop of 5.6 °C comparing with bare cotton fabric and have lower temperatures of 2.5–4.7 °C than their contrast fabrics of the same colour. In addition, the coloured coated cotton fabrics have general moisture permeability, abrasion resistance, excellent mechanical strength and anti-ultraviolet intrusion ability.
The study has been published in Progress in Organic Coatings, Volume 182, September 2023.
