2024-08-26 00:06:27
Researchers have developed a spray gel that creates a shield to protect buildings from wildfire damage that lasts longer and is more effective than existing commercial options, Science Daily reported.
Climate change is causing hotter and drier conditions, causing wildfires to become more frequent and intense, and their seasons longer. In recent years, catastrophic wildfires have destroyed homes and infrastructure, caused devastating losses to people living in affected areas, and damaged natural resources and economies. For this reason, new solutions are being sought to fight forest fires and to prevent the damage caused by them.
Stanford University researchers have developed a water-reinforced gel that can be sprayed on homes and critical infrastructure to protect them from burning during wildfires.
The research, published in the journal Advanced Materials, shows that the new gels last longer and are significantly more effective than existing commercial options.
“Under typical wildfire conditions, current water-enhanced gels dry in 45 minutes. We’ve developed a gel that has a wider window of application. You can spray it long before the fire and still get the protection benefits – it will work better when the fire comes,” says lead author Eric Apple.
The water-enhanced gels are made of super absorbent polymers – similar to the absorbent powder found in disposable diapers. Mixed with water and sprayed onto a building, they swell into a gelatinous substance that adheres to the outside of the structure, creating a thick, wet shield. However, conditions near a wildfire are extremely dry – temperatures can be close to 100 degrees, with high winds and zero humidity, and even water locked in a gel evaporates quite quickly.
In the gel developed by Apple and his colleagues, water is only the first protective layer. In addition to being a cellulose-based polymer, it also contains silica particles that remain when the gel is subjected to heat.
“When the water evaporates and all the cellulose burns, what remains are the silica particles collected in the foam. It is highly insulating and ultimately dissipates all the heat, completely protecting the substrate underneath,” explains Apple.
Silica forms an airgel – a hard, porous structure that is a particularly good insulator. Such aerogels find space applications because they are extremely light and can prevent most methods of heat transfer.
The gels are made of non-toxic components that are already approved for use by the US Forest Service, and researchers are doing studies to show that they are easily degraded by soil microbes.
“They are safe for both people and the environment,” says Eric Apple, quoted by BTA.