Graphene thermal conductivity

Thermal transport in graphene is a thriving area of research, thanks to graphene's extraordinary heat conductivity properties and its potential for use in thermal management applications.

The measured thermal conductivity of graphene is in the range 3000 - 5000 W/mK at room temperature, an exceptional figure compared with the thermal conductivity of pyrolytic graphite of approximately 2000 W⋅m−1⋅K−1 at room temperature. There are, however, other researches that estimate that this number is exaggerated, and that the in-plane thermal conductivity of graphene at room temperature is about 2000–4000 W⋅m−1⋅K1 for freely suspended samples. This number is still among the highest of any known material.

Graphene is considered an excellent heat conductor, and several studies have found it to have unlimited potential for heat conduction based on the size of the sample, contradicting the law of thermal conduction (Fourier’s law) in the micrometer scale. In both computer simulations and experiments, the researchers found that the larger the segment of graphene, the more heat it could transfer. Theoretically, graphene could absorb an unlimited amount of heat.

The thermal conductivity increases logarithmically, and researchers believe that this might be due to the stable bonding pattern as well as being a 2D material. As graphene is considerably more resistant to tearing than steel and is also lightweight and flexible, its conductivity could have some attractive real-world applications.

But what exactly is thermal conductivity?

Heat conduction (or thermal conduction) is the movement of heat from one object to another, that has a different temperature, through physical contact. Heat can be transferred in three ways: conduction, convection and radiation. Heat conduction is very common and can easily be found in our everyday activities - like warming a person’s hand on a hot-water bottle, and more. Heat flows from the object with the higher temperature to the colder one.

Thermal transfer takes place at the molecular level, when heat energy is absorbed by a surface and causes microscopic collisions of particles and movement of electrons within that body. In the process, they collide with each other and transfer the energy to their “neighbor”, a process that will go on as long as heat is being added.

The process of heat conduction mainly depends on the temperature gradient (the temperature difference between the bodies), the path length and the properties of the materials involved. Not all substances are good heat conductors - metals, for example, are considered good conductors as they quickly transfer heat, but materials like wood or paper are viewed as poor conductors of heat. Materials that are poor conductors of heat are referred to as insulators.

How can graphene’s exciting thermal conduction properties be put to use?

Some of the potential applications for graphene-enabled thermal management include electronics, which could greatly benefit from graphene's ability to dissipate heat and optimize electronic function. In micro- and nano-electronics, heat is often a limiting factor for smaller and more efficient components. Therefore, graphene and similar materials with exceptional thermal conductivity may hold an enormous potential for this kind of applications.

Graphene’s heat conductivity can be used in many ways, including thermal interface materials (TIM), heat spreaders, thermal greases (thin layers usually between a heat source such as a microprocessor and a heat sink), graphene-based nanocomposites, and more.

Latest Graphene Thermal Conductivity news

First Graphene launches PureGRAPH product range

First Graphene logo imageFirst Graphene has announces the release of its PureGRAP graphene products. Over the last five months FGR’s management has worked with various universities and on its own production processes to ensure it could consistently produce a suitable range of products.

The initial product includes PureGRAPH graphene products with lateral sizes of 20µm, 10µm and 5µm. Further size options are planned to be added later. FGR says that due to its unique process it is able to produce graphene with larger lateral sheet sizes if a customer should have a particular application.

First Graphene enters agreement to supply graphene to FlexeGRAPH for advanced cooling products

First Graphene logo imageFlexeGRAPH logoFirst Graphene has announced a collaboration agreement with FlexeGRAPH to supply graphene for suitability testing in their products. FlexeGRAPH is developing advanced coolant technology using graphene-enhanced heat transfer fluids.

The nanofluid coolant technologyis said by the Company to represent a breakthrough in liquid coolants, establishing a new standard and showing up to 60% improvements in thermal conductivity over current competitors.

Graphene Batteries Market Report

China-based Shenzhen Danbond begins trials for mass production of graphene film for heat dissipation

A China-based company named Shenzhen Danbond Technology announced that it had begun mass production trials of a self-developed graphene product.

Danbond graphene film for heat dissipation image

The product seems to be a highly-conductive film that can be used in electric vehicle batteries, to dissipate heat in electronic devices and in solar power generation and flexible screens, according to the company. It reportedly plans to begin mass production early next year.

Promethient receives funds to ramp up its graphene-enhanced seat warming application

Promethient, an early stage U.S-based company that developed graphene-enhanced seat warmer technology, has received a large (though undisclosed) equity investment from Faurecia Ventures, the investment arm of Nanterre, France-based Faurecia, the sixth-largest auto supplier in the world, with a big American presence.

The funding will allow Promethient to ramp up product development and marketing and also provides it with a very large early customer. The investment will also allow Promethient to sell to other auto suppliers and makers.

Oakley and Bioracer launch cycling jersey enhanced with Directa Plus graphene

Directa Plus logoDirecta Plus has announced that Oakley, in collaboration with Bioracer, a designer and manufacturer of customized clothing for cycling, have launched the G+ Graphene Aero Jersey containing the Company’s graphene-based products. Unveiled today at the July 2018 EUROBIKE trade show in Friedrichshafen, Germany, the new jersey is designed to leverage the unique properties of Graphene Plus (G+) to dissipate heat from the rider’s body.

Directa Plus' printed G+ planar thermal circuit distributes the heat generated by the body and dissipates it when needed to improve the comfort of the wearer and enable riders to use less energy to regulate their body temperature. Fabrics treated with G+ are also electrostatic and bacteriostatic. These properties contribute to moisture management and have an anti-odor effect, and, if placed on the outside of the garment, G+ reduces the friction with air and water to facilitate top sporting performance.

Versarien - Think you know graphene? Think again! Versarien - Think you know graphene? Think again!