More than hot air
The world of design is increasingly interested in lightweight materials. They’re efficient, usually cheaper by weight than traditional alternatives, and they lend themselves well to light, strong and even temporary structures and designs.
Lightweight materials can also be great insulators, as long as they’re engineered well. Researchers at Berkeley in California have developed super-insulating panels that weigh next to nothing but provide amazing thermal resistance.
Two aspects make these work. The first is to use a strong, lightweight and supple carrier, for instance a mouldable polymer. This is shaped to have a low surface area and contains pockets which are filled with gas. A team at Berkeley constructed panels with hexagonal polymer cells that contain inert gas.
Inert gases are best as they insulate without reacting to external influences, and don’t break down in sunlight. The noble gases, such as helium and neon, are well-known examples of inert gases.
Argon gas increases effective thermal resistance of the material to about R7, or about triple standard building insulation. Using krypton almost doubles argon’s value, and xenon gas is about three times as effective as argon. These values are much higher than achieved with normal foams and wools.
A slightly different concept uses air as the thermal insulator. Aerogel is so light that you can’t feel a smartphone-sized block on your hand. Currently, the material is around 98% air, with the remaining volume a matrix of silicon dioxide – similar to glass. The material is foamed into shape, trapping air and forming the gel-like material that has exceptional insulating qualities.
In both these types of materials, waste reduction and higher thermal performance compared to close-cell foam is possible using gas-filled materials. All these insulating materials are lightweight and low-volume.
We’ve been looking at lightweight materials a lot recently. This important trend is the focus of much design work, as the world transitions towards lightweight buildings, cars, clothes and more.
More from the researchers is here. Images via Berkeley and CreativeCommons licence.