As wildfires become more frequent and intense due to climate change, finding new ways to protect homes and critical infrastructure is more important than ever.
In recent years, wildfires have caused widespread destruction, devastating communities and the environment.
To combat this growing threat, researchers at Stanford University have developed an innovative sprayable gel that could help shield buildings from the flames.
This new gel, detailed in a study published in Advanced Materials, lasts longer and works better than current products on the market.
Traditional water-enhancing gels, which are often used to protect structures during wildfires, dry out quickly under extreme conditions.
According to Eric Appel, an associate professor of materials science and engineering at Stanford and the study’s senior author, these gels usually lose their effectiveness within 45 minutes.
However, the gel developed by Appel and his team is different. It can be sprayed well in advance of a wildfire and still provide protection when the fire arrives. This longer-lasting protection is possible because of the gel’s unique composition.
Water-enhancing gels are made from super-absorbent polymers, similar to those found in diapers, which swell into a thick, wet coating when mixed with water and applied to a surface. But in the dry, hot conditions near a wildfire, even these gels evaporate quickly.
The new gel created by Appel’s team includes not only a cellulose-based polymer but also silica particles that remain after the water evaporates and the cellulose burns away.
Lead author Changxin “Lyla” Dong explains that when exposed to heat, the gel undergoes a transformation. As the water evaporates and the cellulose burns off, the silica particles form a protective foam.
This foam is an aerogel, a solid structure with tiny pores that is an excellent insulator. Aerogels like this are even used in space because they are lightweight and can block heat effectively.
To test their new gel, the researchers applied it to pieces of plywood and exposed them to flames from a gas torch. The most successful version of the gel protected the wood for more than seven minutes, while a commercially available gel only lasted 90 seconds. Appel noted that even after drying out, their gel continues to protect the treated surfaces by forming a heat-resistant aerogel.
This discovery builds on previous work by Appel and his team, who have been exploring ways to use gels to prevent wildfires for several years. While the development of this new gel was somewhat accidental, it shows great promise. The gel is made from non-toxic materials that are safe for both people and the environment, and it breaks down easily in the soil.
Appel hopes that with some additional fine-tuning, these gels can be tested on a larger scale and eventually used to protect homes, buildings, and other critical infrastructure from the devastating effects of wildfires.
