Yesterday afternoon (June 5) afternoon, money newspaper reporter in polymer system lab, zhejiang university, met this mysterious material: it has the highest thermal conductivity of 2053 w/mK (watt/per meter per degree), can be comparable to the world the most advantage of thermal conductivity of diamond material, created the world macroscopic materials thermal conductivity of new records;It is also super flexible, capable of being folded over 6,000 times and subjected to 100, 000 times of bending.
This is a new material "graphene film" made by a team of excellent professors in the department of polymer of zhejiang university. It solves the global problem that the macroscopic material can not combine high thermal conductivity with high flexibility.
In the new issue of Advanced Materials, a leading international journal of Materials science, professor gao's team published papers on the new material, which is expected to have important applications in the new generation of flexible electronics, aerospace and other fields.
Either cold or fragile
Most electronic devices have a "straight man" personality: good heat conductivity, but not flexible enough.For example, some inorganic ceramic crystal materials, high thermal conductivity, but very fragile.It seems that men are handsome and handsome, but too much male chauvinism, a word can collapse;
For another example, metal material has good ductility, but its thermal conductivity is about 429W/mK.This kind of material if is "man", the boyfriend is tall, quarrel can let you, but not gao cold.
It wasn't until professors Andre Geim and Konstantin Novoselov, of the university of Manchester in the United Kingdom, discovered graphene, a combination of mild and cold, that they were awarded the 2010 Nobel Prize in physics.
The "ideal boyfriend", graphene, a carbon material, has been found, which offers theoretical possibilities for "combining heat conductivity with flexibility".
Unfortunately, the reported powdery graphene is small and defective.The macroscopic materials assembled from them are less heat-conducting and flexible than the graphite membranes that have been commercialized.
What is graphite film?It's on the back of your phone.Its heat dissipation capacity is basically able to withstand the high power of the mobile phone work, the most is when playing games a bit hot;Common graphene sheets are flexible enough to fit together with plastic -- a bend is ok, but if folded several times, they break.
Where on earth are the oxen and graphite film PK
However, graphene is certainly not easily abandoned as a potential stock, as evidenced by the market's attention to graphene concept stocks.
In 2013, the team produced the world's lightest solid carbon sponge.On the day of the report, graphene-related mainland stocks were red.
This time, the superb team creatively proposed the new idea of "large micro-folds", and prepared graphene membranes -- by overlapping large sheets of graphene and making them into macroscopic graphene membranes, high thermal conductivity could be achieved.The graphene membranes are then added with a microfold structure to give the material enough room to stretch and bend, ensuring high flexibility.
Yesterday, in the laboratory of zhejiang university, qian newspaper reporter saw graphene membrane in close quarters for the first time, the color is similar to seaweed, soft like cloth.
How did it work?The superb team bought a phone that is currently on the market as the most advanced backplane cooling film.The graphene membranes made by them and the graphene membranes behind the mobile phones were compared and tested:
It's better than heat conductivity.Is also play the game, the king of glory through the graphite film cooling of the cellular phone, measure to the backplane CPU temperature is about 39 ℃.Mobile phone and switch to using graphene membrane, backplane 33 ℃ temperature.
Although only 6 ℃ difference, but generally speaking, mobile temperature increase 8-10 ℃, the higher the frequency of the "high fever", scrap term will come sooner.And the failure rate of electronic products is more than 50% due to high temperature.
It's more flexible.At present, the most advanced graphite film material can be folded in the same direction for 6 times.The excellent team's graphene membrane can withstand more than 100,000 times of bending without affecting its thermal conductivity.Even more amazing, the graphene membrane still hasn't broken after repeated folding of 6,000 times.
In the future, human career is still about down-to-earth life and stargazing exploration.
Imagine if a phone were to be buckled around the wrist like a bracelet. At least graphene membranes, which conduct heat, have cracked the problem.
Higher-end applications can also be found in exploring the wonders of the universe. Spacecraft flying out of outer space are also faced with the problems of material saving, weight reduction, face facing and back facing the sun with huge temperature difference.