New cheap heatshield coating repels near-boiling water on any surface

Researchers at Rice University have developed a novel multilayered insulated superhydrophobic (MISH) coating that effectively repels near-boiling liquids such as hot water, milk, coffee, and soup on various surfaces. Traditional superhydrophobic coatings lose their water-repellent properties at temperatures above 104°F (40°C) because hot droplets cause evaporation-condensation cycles that flood surface textures with condensate, leading to wet patches. The MISH coating overcomes this by combining an insulating underlayer of spray-on polyurethane foam with a microtextured superhydrophobic topcoat. The insulation slows heat transfer, reducing condensation and maintaining repellency even at temperatures up to 194°F (90°C). In rigorous testing, the MISH coating withstood nearly two million hot droplet impacts over 80 hours without significant degradation, far outperforming conventional coatings that failed almost immediately. The main limitation identified was the durability of the commercially available topcoat, suggesting that future improvements could extend the coating’s lifespan. The