Graphene is already hailed as the future of engineering, holding great promise for lighter, more efficient and rapid CPUs, headphones, solar cell development, and others.
Now, white graphene or 3D structures of hexagonal boron nitride comes to steal the spotlight. A team of researchers from Rice University, supported by the Rice Department of Environmental and Civil Engineering, as well as by the National Science Foundation completed their study on white graphene and its applications.
Navid Sakhavand and Rouzbeh Shahsavari looked at the properties of hexagonal boron nitride in comparison with graphene and made a 3D model of white graphene that is far better at dissipating heat than graphene.
While a graphene structure is highly efficient at conducting electricity without any barriers, as well as heat, cross-layer heat flow is not as smooth. The hexagonal boron nitride atom has the same structure as that of graphene, yet it is more efficient in what regards heat flow or phonons flow.
Thus, the research team set out to create a 3D white graphene structure connected by nanotubes of different diameters and sizes and made of the 2D hexagonal boron nitride. The 3D white graphene structure holds the key for the cooling technologies of the future, possibly implemented in small electronic devices.
3D white graphene was found to be the best material to finetune and efficiently control heat flow. With the natural insulating properties of the hexagonal boron nitride, the nanotubes creating the joints of the 3D white graphene structures transferred heat across all layers and surfaces equally, albeit at a decreased speed.
Rouzbeh Shahsavari stated:
“Typically in all electronics, it is highly desired to get heat out of the system as quickly and efficiently as possible. One of the drawbacks in electronics, especially when you have layered materials on a substrate, is that heat moves very quickly in one direction, along a conductive plane, but not so good from layer to layer. Multiple stacked graphene layers is a good example of this”.
Previous research efforts have yielded results in the form of carbon/graphene nanotube junctions to address heat flow. Yet, the Rice University researchers believe that 3D white graphene structures could be complementary to the creation of graphene nanoelectronics.
Thermal switches or rectifiers could be the outcome of new technology aimed at more performant electronic devices. Playing with the weight, size and shape of the structure once its basic properties are understood could bring about a great number of applications.
The results of the research conducted by Shahsavari and Sakhavand can be read in the American Chemical Society journal of Applied Materials and Interfaces.
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