Scientists have developed a highly thermally conductive ultra-flexible graphene assembly film

Recently, Zhejiang University's high-molecular department team developed a high thermal ultra-flexible graphene assembly film, thermal conductivity of up to
2053W/mK (
watts
/
meters open
)
, close to the ideal single-layer graphene thermal conductivity of
40%
, creating a new record of macro-material thermal conductivity
;
at the same time, the material is assembled from micro-folded large pieces of graphene, with ultra-flexible, can be repeatedly folded
6000
times, subject to bending 100,000 times.this latest achievement solves the world-wide problem of high thermal conductivity and high flexibility of macro materials, and is expected to be used in areas such as efficient thermal management, a new generation of flexible electronics and aerospace. The article was published in Advanced Materials.electrical and electronic appliances will be hot when working, the need for efficient thermal management to ensure its normal operation. The next generation of devices also requires bendability. However, the high thermal conductivity and high flexibility of existing macro-materials are often difficult to combine. The emergence of graphene provides a theoretical possibility to solve this contradiction.that the super team creatively put forward the idea of "large areas of micro-folds": large areas of graphene defects less, can achieve high thermal conductivity
;
folds allow the material enough strain space to stretch and bend, ensuring high flexibility.told China Science Daily that the new idea is easy to come by. Three steps can be completed: large areas of graphene oxide water dispersion by scraping into a film
;
high temperature heat treatment, the oxygen-containing energy group in the membrane decomposes at high temperature, releasing gas, and with the increase of temperature, graphene defect structure is gradually repaired, the gas is blocked inside the graphene film, due to expansion to form a micro-airbag
;
the mechanical rollers into a film, the gas of the micro-airbags is excreted under the pressure, forming micro-folds.researchers also used debris-free ultra-large pieces of graphene oxide as a raw
,
to reduce edge acoustic escape. At the same time, the use of high-temperature heat treatment, remove the graphene surface of the official energy group and repair the internal holes of graphene, to obtain less defective graphene structure. These structural changes are confirmed by
,
XRD and transmission mirror detection. The average thermal conductivity of the resulting graphene film is
1900W/mK
, with a maximum value of
2053W/mK
.。