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

10 graphene-enhanced products already on the market

Graphene has been attracting attention due to its exciting properties and countless ideas for applications benefiting from those properties have been thought of; However, it is rightfully claimed that graphene has yet to transform an actual industry or become a household name.

With that said, graphene seems to be slowly but surely entering the market in all sorts of products. In this post, we list 10 products already commercially available that contain graphene - and these are not all of them. Hopefully this is just the beginning and many more applications will follow.

International wheel producer Vittoria sells a range of bicycle wheels that are built from graphene-enhanced composite materials. The wheels, called Quarno (Graphene Plus inside) are available in three different editions (46, 60 and 84 mm) and contain graphene nanoplatelets (GNPs) provided by Directa Plus. The company explains that the graphene grants the wheels advantages like heat dissipation (15-30°C lower) – a crucial factor in the slopes, an increase in lateral stiffness (more than 50%) and puncture reduction, especially around the valve area.

Directa Plus and Iterchimica develop new graphene-enhanced asphalt additive

Directa Plus logoDirecta Plus has announced its collaboration with Iterchimica, am Italy-based producer and distributor of specialized additives for asphalt. The collaboration with Iterchimica is focused on developing a graphene-enhanced asphalt additive, which is patent-pending, that can significantly improve the durability and sustainability of asphalt road surfaces.

The new additive incorporating the Directa’s Graphene Plus (G+) has been launched by Iterchimica as "Eco Pave". As per reports, the success of laboratory and small-scale trials convinced Iterchimica to conduct a pilot test where Eco Pave will be used as an additive for asphalt covering several kilometers of road surface.

The Graphene Handbook

Manipulating the joints between graphene and CNTs could improve heat transfer

Researchers at Rice University have built atom-level computer models of pillared graphene—sheets of graphene connected by covalently bonded carbon nanotubes—and discovered that manipulating the joints between the nanotubes and graphene has a significant impact on the material's ability to direct heat. The team stated that this could prove important as electronic devices shrink and require more sophisticated heat sinks.

Rice team studies thermal properties of graphene-CNTs junctions image

Researchers who study or are working to make pillared graphene have primarily viewed two characteristics of the theoretical material: the length of the pillars and their distance from each other. The new study suggests that a third parameter—the nature of the junction between the graphene and nanotubes—should also be considered.

IIT and FADEL unveil graphene-enhanced shoes

Graphene Flagship partners Istituto Italiano di Tecnologia, Italy, in collaboration with FADEL, a leading Italian shoe company, have developed graphene-enhanced shoes. The new GET technology, patented by FADEL, reportedly gives the footwear better thermoregulation and freshness.

IIT and Fadel develop graphene-enhanced shoes image

In this innovative shoe, when flakes consisting of several graphene layers are added to polyurethane, (the material of which the soles of FADEL shoes are made), laboratory tests show an augmented heat dispersion, a greater resistivity to water and enhanced antibacterial properties. Combining these effects with a ventilation system developed for this particular type of shoe yielded a better user experience. This prototype shoe was presented at the International Footwear Exhibition in Milan.

Gaming company launches graphene-enhanced SSD

Team Group, memory solutions and accessory provider, has announced the addition of new products to their existing T-FORCE gaming line of products. Among the new products is the T-FORCE CARDEA ZERO M.2 PCI-E solid-state drive, featuring graphene copper foil cooling on the SSD module allowing the SSD to maximize cooling benefits from both natural passive cooling and directed air cooling via fans to deliver excellent heat dissipation.

Graphene-enhanced gaming drive image

According to the company, the T-FORCE CARDEA ZERO M.2 PCI-E SSD is the world’s first super slim SSD on the market built specifically for gaming laptops and high-performance tablet PCs. Utilizing graphene provided by Nitronix and designing combinations of different proportions of graphene and copper foil, the patented graphene copper foil heat spreader was reportedly achieved through stringent multiple verification. It offers excellent thermal cooling effect even in a closed space.

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