What is aerogel?

Aerogel is created by combining a polymer with a solvent to form a gel, and then removing the liquid from the gel and replacing it with gas (usually air). The high air content (99.98% air by volume) makes it one of the world's lightest solid material. Aerogels can be made from a variety of chemical compounds, and are a diverse class of materials with unique properties. They are known as excellent insulators, and usually have low density and low thermal conductivity.

Aerogels can be used in various applications, and although they have been around since the 1930s, their development is still progressing (for example, NASA's Glenn Research Center in Cleveland has invented several groundbreaking methods of creating new types of aerogels).

Common applications include enhancing the thermal performance of energy-saving materials and sustainable products for buildings, acting as a high performance additive to coatings, prevention of corrosion under insulation, uses in imaging devices, optics, and light guides, thermal breaks and condensation control, architectural lighting panels, outdoor and sports gear and clothing, and more.

Graphene aerogel

Graphene aerogel, also known as aerographene, is considered to be the least dense solid in existence (graphene aerogels are light enough to be balanced on small plants!).

Graphene aerogels are quite elastic and can easily retain their original form after some compression. In addition, the low density of graphene aerogels makes them very absorbent (to the point where it can even absorb more than 850 times its own weight). This means that it could be useful for environmental clean-ups like oil spills, and the aerogels only need to be picked up later after absorbing the spilled material. Graphene aerogel may also have some applications in both the storage and the transfer of energy by enabling the creation of lighter, higher-energy-density batteries - and vigorous research is being done on the matter.

Graphene aerogel are somewhat similar to graphene foams. Graphene foams are usually made by CVD growth on a metal structure (which is later removed), and are so more conductive than graphene aerogels.

Graphene aerogels are already being sold commercially, for about about $300 per gram.

Latest Graphene Aerogel news

Rice team gives epoxy a graphene boost

Rice University scientists have developed a graphene-based epoxy for electronic applications. Epoxy combined with graphene foam invented in the Rice lab of Prof. James Tour) is reportedly substantially tougher than pure epoxy and far more conductive than other epoxy composites, while retaining the material's low density. It could improve upon epoxies in current use that weaken the material's structure with the addition of conductive fillers.

Rice team gives epoxy a graphene boost image

By itself, epoxy is an insulator, and is commonly used in coatings, adhesives, electronics, industrial tooling and structural composites. Metal or carbon fillers are often added for applications where conductivity is desired, like electromagnetic shielding. The trade-off, however, is that more filler brings better conductivity at the cost of weight and compressive strength, and the composite becomes harder to process. The Rice solution replaces metal or carbon powders with a 3D foam made of nanoscale sheets of graphene.

New graphene scaffold capacitors break capacitance records

Researchers at the University of California, Santa Cruz and Lawrence Livermore National Laboratory in California have developed a new fabrication technique to make capacitors enhanced with graphene. The resulting devices store a large amount of charge over a given surface area - an important metric for measuring the performance of a capacitor.

The new technique uses a 3D printer to construct a microscopic scaffold with porous graphene and then fills the structure with a kind of material called a pseudocapacitive gel, which is a kind of capacitor material that also behaves like a battery in some ways.

The Graphene Catalog - find your graphene material here

A new method may enable 3D printing complex structures with graphene

Researchers from Virginia Tech and Lawrence Livermore National Laboratory have developed a new way to 3D print with graphene. Graphene has previously been used in extrusion-based processes to print single sheets and basic structures at a resolution of around 100 microns, but this latest research shows it is also possible to use a stereolithography-based technique to print “pretty much any desired structure” down to 10 microns, close to the size of actual graphene sheets. The ability to 3D print functional parts in graphene could benefit many industries and products.

Graphene aerogel for 3d printing image

“Now a designer can design three-dimensional topology comprised of interconnected graphene sheets,” said Xiaoyu “Rayne” Zheng, assistant professor with the Department of Mechanical Engineering in the College of Engineering and director of the Advanced Manufacturing and Metamaterials Lab. “This new design and manufacturing freedom will lead to optimization of strength, conductivity, mass transport, strength, and weight density that are not achievable in graphene aerogels.”

NUS team develops novel technique for mass production of graphene

A research team led by the National University of Singapore (NUS) and conducted in collaboration with Fudan University has developed an economical and industrially viable strategy to produce graphene. The new technique may offer a way for efficient large-scale production of graphene, to pave the way for sustainable synthesis of the material.

The conventional method of producing graphene utilizes sound energy or shearing forces to exfoliate graphene layers from graphite, and then dispersing the layers in large amounts of organic solvent. As insufficient solvent causes the graphene layers to reattach themselves back into graphite, yielding one kilogram of graphene currently requires at least one tonne of organic solvent, making the method costly and environmentally unfriendly.

Graphene and CNTs used together to create new stretchable aerogels

Researchers at Zhejiang University in China have designed a new type of aerogels, made of graphene and carbon nanotubes, that can be reversibly stretched to more than three times their original length, displaying elasticity similar to that of a rubber band. This stretchability, in addition to aerogels' existing properties like ultralow density, light weight, high porosity, and high conductivity, may lead to exciting new applications.

The scientists designed carbon aerogels consisting of both graphene and multi-walled carbon nanotubes assembled into four orders of hierarchical structures ranging from the nanometer to centimeter scale. To fabricate the material into aerogels, the researchers created an ink composed of graphene oxide and nanotubes, and then formed the aerogels via inkjet printing.

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