Nature-Inspired Safer Alternative to Road Salts Is in the Works

A group of scientists from the University of Denver is developing alternatives to the harmful road salts that are used to lower the freezing point of water, causing disruptive snow to thaw from our roads in snowy months, as per a report on the World Economic Forum. 

Road salts are typically a less-refined form of table salt, or sodium chloride, that can also include other compounds, such as magnesium chloride and potassium chloride.

The problem with these types of salts is that, despite the fact that nearly 20 million tons are used on U.S. roads per year, they cause extensive damage to vehicles, road infrastructure, and the environment.

For example, a 2010 study estimated that the use of de-icing salts costs U.S. drivers US$23.4 billion dollars annually in vehicle damage due to corrosion.

The chlorine ions in road salts also damage roads by altering the chemistry of water and making it more corrosive when it comes in contact with materials like concrete and steel. De-icing has even contributed to bridge failures.

The salts also have a widespread effect on nature: they displace minerals in soil and groundwater, creating a condition known as physiological drought, a factor that can contribute to wildfires. What's more, waterways, and their ecosystems, are particularly vulnerable to water runoff that contains de-icing salts.

Drawing inspiration from nature's antifreeze mechanisms

The scientists from the University of Denver have looked to the natural world for solutions on how to deal with ice — fish, insects, and even some plants have evolved over millennia to make their own antifreeze agents that help them survive subfreezing temperatures.

By studying these natural antifreeze methods, the researchers hope to "develop effective but more benign antifreeze compounds," Monika Bleszynski, Research Scientist and Adjunct Professor at the University of Denver, says in her WEF write-up.

Insects and spiders found in Alaska create antifreeze proteins in their bodies that lower the freezing point of water by a few degrees. Fish such as the Antarctic toothfish also create antifreeze glycoproteins that prevent the blood in their veins from freezing in the Earth's coldest waters.

Bleszynski says she and her colleagues are learning to make their own antifreeze compounds through imitation. The first challenge, however, is to fully understand how the natural versions work so they can be re-created.

The team is using advanced computer modeling to see how antifreeze proteins interact with water molecules. Their work adds to previous research from other scientists that has shed light on the critical process through which the proteins bind to developing ice crystals, preventing them from getting bigger.

Using PVA — an inexpensive compound found in many household products — as a base, the University of Denver team is also creating and tinkering with synthetic versions of these compounds in a lab with a view to eventually creating an easy-to-make ice-fighting substance that would not corrode roads, cars, and would be harmless to ecosystems.