Physicists at the University of Colorado Boulder have developed a new window-insulating material that could boost building energy efficiency worldwide—and it works much like a high-tech version of Bubble Wrap.
The material, known as the Mesoporous Optically Clear Heat Insulator (MOCHI), is produced as large panels or thin films that can be placed on the interior surface of any window. For now, the team manufactures MOCHI only in the lab, and it isn’t yet commercially available. According to the researchers, the material is durable and nearly fully transparent.
In other words, it won’t interfere with your view—unlike many existing insulation products.
The Challenge of Creating Transparent Insulation
“To stop heat transfer, you can pack plenty of insulation into your walls, but windows have to stay clear,” said Ivan Smalyukh, the study’s senior author and a physics professor at CU Boulder. “It’s extremely difficult to find insulators that are also transparent.”
The findings were published in Science.
Buildings—from houses to tall office towers—account for roughly 40% of global energy use. They also tend to lose conditioned air, letting heat escape during cold weather and allowing heat to seep in when it’s warm.
Smalyukh and his team want to reduce this unwanted transfer.
Their MOCHI material is a silicone-based gel with a unique feature: it contains a network of microscopic pores, each far thinner than a strand of human hair, which trap air. These tiny air pockets are so effective at insulating that a MOCHI layer only 5 millimeters thick can let you safely hold a flame against your hand.
“Our goal is to help people maintain comfortable indoor temperatures without wasting energy, no matter what it’s like outside,” said Smalyukh, a fellow of the Renewable And Sustainable Energy Institute (RASEI) at CU Boulder.
Smalyukh explained that MOCHI’s effectiveness lies in carefully controlling those tiny air pockets.
The team’s invention resembles aerogels, a well-known family of insulating materials used in many applications today. (For example, NASA relies on aerogels in its Mars rovers to keep electronics warm.)
Aerogels, like MOCHI, trap vast numbers of air pockets. However, in aerogels those bubbles are arranged randomly and often scatter light instead of letting it pass through. As a result, aerogels usually appear hazy—earning them the nickname “frozen smoke.”
In this project, Smalyukh and his team decided to rethink how insulation can be designed.
The Science Behind MOCHI’s Formation
To create MOCHI, they add surfactant molecules to a liquid mixture. These molecules naturally gather into slender strands, much like the way oil and vinegar separate in salad dressing. Silicone molecules in the mixture then begin attaching themselves to the surfaces of these strands.
Through additional processing steps, the researchers remove the surfactant clusters and replace them with air. What remains is silicone forming a framework of extremely fine, air-filled channels—something Smalyukh jokingly describes as a “plumber’s nightmare.”
Overall, air accounts for more than 90% of MOCHI’s total volume.
Smalyukh explained that heat moves through gases in a way similar to a game of pool: when heated, gas molecules and atoms become energized and collide with one another, passing energy along.
But in MOCHI, the air pockets are so tiny that the gas molecules inside don’t have room to collide freely, which dramatically slows the flow of heat.
The Science Behind MOCHI’s Insulation
“The molecules can’t easily bump into each other to exchange energy,” Smalyukh said. “Instead, they mostly hit the walls of the pores.”
Despite this structure, MOCHI reflects only about 0.2% of the light that hits it.
The team envisions many potential applications for this transparent insulator. Engineers might create devices that use MOCHI to capture heat from sunlight and convert it into low-cost, sustainable energy.
“Even on a somewhat cloudy day, you could still gather plenty of solar energy and use it to heat your water or your building,” Smalyukh noted.
These innovations won’t reach the market immediately. Producing MOCHI currently requires a slow, labor-intensive process in the lab. But Smalyukh is optimistic that production can be scaled up, especially since the materials needed to make MOCHI are relatively cheap—an encouraging sign for eventual commercialization.
For now, the outlook for MOCHI—much like the view through a window coated in it—remains bright.
Read the original article on: Techxplore
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