Along with water, sprays also attract dirt, dust, oil and other impurities, and the slightest impurity on the surface renders it useless. That’s why you always have to reapply those sprays, and they’re not durable.
On the other hand, we also have so-called super-hydrophobic coatings, which repel water. The issue there is scalability, specifically on glass. Like gold coating, super-hydrophobic coatings also use heating to prevent fogging, but instead of a renewable source such as sunlight, they use electricity to generate heat.
This is why researchers consider hydrophobic coatings to be an energetically inefficient and sustainable way to keep surfaces fog-free.
“Our underlying motivation was to show the vast potential of solar power, and how less sustainable technologies (such as the use of electricity to prevent fogging) can be prevented by applying material concepts and rational engineering. Therefore, ideally , our coating contributes to reducing the power consumption for heating,” explains Heckler. meaning,
This can be helpful, especially for electric cars. In normal cars, hot air from the engine can be used to convectively blow over the windshield and remove fog. Electric engines don’t get very hot. The authors believe that by using their gold-based coating, we could extend the range of electric cars, as these cars would use less electricity to prevent fogging.
made of gold but still cheap
They further claim that apart from using a natural source of electricity (sunlight). Their coating is made with standardized, easily scalable methods and can be easily scaled up over large areas, all cost-effectively. However, since the coating uses pure gold, would it be commercially viable to make eyewear and car windshield fog covers using it?