New technique to make heat pass through plastic
Published : 11 Aug 2017, 16:19
Researchers in materials science and mechanical engineering at the University of Michigan (UM) have developed a new technique that can change plastic's molecular structure to help it cast off heat.
The new technique uses a process that engineers the structure of the material itself, considering the nature of plastics made of long chains of molecules that are tightly coiled and tangled like a bowl of spaghetti.
It used a chemical process to expand and straighten the molecule chains, giving heat energy a more direct route through the material.
To accomplish this, the researchers first dissolved a typical polymer, or plastic in water, then added electrolytes to the solution to raise its pH, making it alkaline.
The individual links in the polymer chain, called monomers, take on a negative charge, which causes them to repel each other. As the monomers spread apart, they unfurl the chain's tight coils.
Finally, water and polymer solution is sprayed onto plates using a common industrial process called spin casting, which reconstitutes it into a solid plastic film.
The uncoiled molecule chains within the plastic make it easier for heat to travel through it.
Researchers also found that the process has a secondary benefit: it stiffens the polymer chains and helps them pack together more tightly, making them even more thermally conductive.
"Polymer molecules conduct heat by vibrating, and a stiffer molecule chain can vibrate more easily," said Apoorv Shanker, a materials science and engineering graduate student.
"Think of a tightly stretched guitar string compared to a loosely coiled piece of twine. The guitar string will vibrate when plucked, the twine won't. Polymer molecule chains behave in a similar way," Shanker added.
The process is a major departure from previous approaches, which have focused on adding metallic or ceramic fillers to plastics, a process that is expensive as well as can change the properties of the plastic in undesirable ways.
The work has important consequences because of the large number of polymer applications where temperature is important.
The study has been published in the journal Science Advances.
- Most viewed
- Vegetable egg ‘bhurji’
- More pregnant women are having heart attacks
- Be a host to provide Non-Alcoholic summer drinks
- Girl gang raped in Narayanganj
- Work for people, Prime Minister to officials
- HC orders Cumilla court to dispose of Khaleda’s bail plea by July 26
- Shooter dead after killing one woman and injuring 13 others in Canada
- 9 people shot in Canada, shooter dead: police
- 23 July Events
- AL to hold mass reception to Prime Minister today
- Use jute bags, break up with plastics: Prime Minister
- Bangladeshi Sharmin wins Commonwealth recognition
- Russian woman charged with spying in US
- British PM’s trade envoy Rushanara due today
- Quota movement is discreet campaign against FFs children
- HSC, equivalent exams results tomorrow
- World Cup Pussy Riot pitch intruders jailed for 15 days
- PM Sheikh Hasina opens G2P system for freedom fighters