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

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.