Passive cooling performance of polyacrylamide hydrogel on wooden and brick houses and effect of nanoparticle integration on its mechanical strength

Abstract

ABSTRACT Thermoresponsive hydrogels have been studied in the past as self-healing and ultra-porous materials. Single-network (SN) and double-network (DN) hydrogels were synthesised in this research using acrylamide, acrylic acid, and alginate. Nano reinforcements were added only to increase the mechanical strength which is reported up to 300%. These DN hydrogels showed brilliant cooling performance showing 8–12°C lesser in a coated house for over 7 h with a single hydration cycle. Tough hydrogels were tested under direct sunlight on wooden and brick houses during the summer of Pakistan, where a 10–20°C temperature difference was reported. Thermographs and FTIR spectra showed that the ionic and covalent crosslinkers were responsible for the excellent robustness. DN hydrogel gave better strength and cooling effectiveness for a longer period than SN hydrogels. Carbon emission and electricity consumption can be reduced using DN hydrogels. These hydrogels can aid the industry of smart buildings and passive cooling.