Snow imagery often rings in the winter season, but not everyone gets to enjoy it. Even for those in northern climates, snow needs an ideal balance of weather conditions to form. Understanding that not everyone can enjoy the fun and excitement of this wintertime delight, researchers developed a solution: synthetic snow.
A happy accident
In the 1940s, a group of scientists in Canada aimed to study how ice could impact the productivity of airplanes’ jet engines. In their attempts to create ice by spraying water vapor in front of the airplane’s tunnel-like engine, the vapor was instead sucked into the low-temperature engine and formed snow crystals. Here formed the basis behind snowmaking: spraying water droplets into a high-pressure propeller or tube with compressed air to generate liquid droplets that then freeze as gravity pulls them downward.
On a large scale, the most common use of artificially created snow is in wintertime athletics or sports (such as at ski resorts). In 1950, Wayne Pierce, Art Hunt, and Dave Richey — who founded a ski-making business in Connecticut — faced a largely snow-less winter. Drawing on the scientists’ findings and seeking to reverse their business’s shortcomings, they patented the first snowmaking machine in 1954. Over the next 20 years, other inventors continued to develop the design behind the snowmaking machine, increasing the efficacy of the process.
How synthetic snow is made
Snowmaking machines are designed to produce fine water particles that freeze quickly but are large enough not to be blown away before they reach the ground. At the same time, pure water only freezes completely around -40°C, which is not always feasible to maintain.
To allow these water molecules to freeze at higher temperatures, snowmakers mix “nucleating agents” into the water. These particles give water molecules something to cling to so that they can more easily form crystalline ice structures with one another — without needing the very low temperatures that slow the molecules down and lock them in place.
But you don’t need a research lab to create your own snow. Research has also found a way for everyday snow lovers to generate artificial snow in their own home, using sodium polyacrylate — a white, absorbent polymer with a high molar mass — and water. When sodium polyacrylate comes into contact with water, its lengthy polymer chains rapidly absorb liquid, forming a gel-like substance that mimics the appearance and feel of snow.
Not always fun and flurries
There are, however, shortcomings to the development of this synthetic snow.
Researchers have found that the nucleating agents used on a large scale by ski resorts are often environmentally damaging due to their potentially-toxic implications on wildlife. Additionally, the development of water management systems that employ treated wastewater or recycled water can reduce the environmental impact of such snowmaking machines.
It also has implications in the world of winter sports. Synthetic snow often packs together densely in comparison to looser, powder-like natural snow — of which, on the slopes, consists of around 95% air. While elite racers often prefer the icier feel of synthetic snow to generate power and make sharp turns, those who ski at their leisure often find natural snow easier to ski on.
For these reasons, the existing landscape of synthetic snow is one in which innovation pervades, in both the maintenance and development of this ubiquitous wintertime creation.
Polymer Research at Emory
While not related to the making of synthetic snow, researchers based at Emory University are studying the applications of polymers in a number of fields. For one, Emory physics professor Connie B. Roth, PhD, studies how mixing different polymer blends allows their properties to gradually transition and blend across these intersections. Roth’s work won her a National Science Foundation (NSF) Special Creativity award, but goes further than academia, having practical applications to the durability and composition of products from medical equipment to food containers.
Additionally, Emory researchers have joined with Georgia Tech researchers to explore the ways that protein polymers can create or support membraneless organelles, which are membrane-less structures within cells that perform cellular functions. This research has significant applications in cell therapy and immunotherapy, as it could help cells reverse the impacts of losing certain organelles due to diseases or disorders.
— Ava Westreich