Engineers and scientists have embarked on the race of a lifetime to perfect energy efficient refrigeration technologies. At this point in time, refrigeration technologies are a large contributor to greenhouse gases due to their amount of electricity consumption.
A group of international researchers at the Chinese Academy of Sciences have reported that they have come closer to perfecting a new form of refrigeration that achieves a cooling effect utilizing crystal plastics.
Instead of compressing gas in the traditional way refrigerators do it, the researchers attempted to apply pressure to the plastic crystal. The result is a change in the molecular structure of the crystal plastics, which rapidly absorbs any heat.
Dr Bing Li, one of the researchers of the study, speaking to The New Scientist said:
“We identified plastic crystals as promising materials for solid-state refrigeration. A tiny pressure can switch the materials between the disordered state and the ordered state, resulting in a large change in energy.”
Within the crystal, the molecules compress and decompress which in turn produces a cooling effect. Dehong Yu of Australia’s Nuclear Science and Technology Organisation (ANSTO) speaking to ABC News said:
“One cycle will cause a 50-degree difference in room temperature with very little pressure. This is a perfect example of where we use our fundamental research to lead into a real thing that can benefit our everyday life.”
One of the plastic crystal compounds known as neopentyl glycol reportedly has an ‘energy change tens of times greater than other potential solid refrigerants’. The compound can absorb much more heat than solid coolants at the same pressure.
The researchers are calling it ‘atomic refrigeration’ and it could make its way into range of other consumer products. It could especially be used in air conditioners.
However, there is still some innovation required with the plastic crystals. The researchers point out that some more trial and error is needed to make them more viable as a refrigerating alternative. They write:
“Nevertheless, plastic crystals are not perfect caloric materials. For instance, given their organic nature, they have relatively low melting points (typically about 300-400K) which is not desirable for refrigeration applications. In addition, the properties that make plastic crystal highly deformable mean that these materials lack the mechanical resilience to endure many refrigeration cycles.”
Thus, the crystal in its current form still requires some further development before it replaces traditional cooling methods. This is where traditional refrigerators have an upper hand; gases can be cycled without end and determination.
However once plastic crystals has been perfected, cooling technologies could microchip-sized. It is now up to the engineers and scientists to figure out how to ensure multiple cooling cycles and scale the technologies appropriately.
Cazorla, Claudio. “Refrigeration Based on Plastic Crystals.” Nature News, Nature Publishing Group, 27 Mar. 2019, www.nature.com/articles/d41586-019-00974-5.
Lu, Donna. “Fridges Made from Plastic Crystals Could Help Cut Carbon Emissions.” New Scientist, www.newscientist.com/article/2197805-fridges-made-from-plastic-crystals-could-help-cut-carbon-emissions/.
Weule, Genelle. “Your Fridge Is Bad for the Environment. Here's What Could Someday Replace It.” ABC News, Australian Broadcasting Corporation, 28 Mar. 2019, www.abc.net.au/news/science/2019-03-28/plastic-crystals-could-keep-us-and-the-planet-cool-in-the-future/10943796.