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, 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.
The latest Graphene Aerogel news:
SmartIR, a spin-out of the University of Manchester, is working on a graphene-based smart coating for satellites, to allow them to control thermal radiation on demand, depending on whether a satellite’s surface is Earth’s shadow or on the side closest to the Sun.
This graphene technology is said to be a far more optimal solution as it is lightweight, has a low power consumption, can respond quickly to temperature changes, operates across the infrared spectrum, and involves no moving parts.
Researchers use 3D printing to make graphene aerogel flow-through electrodes for electrochemical reactors
Scientists at Lawrence Livermore National Laboratory (LLNL) are 3D printing graphene aerogel flow-through electrodes (FTEs), core components of electrochemical reactors used for converting CO2 and other molecules to useful products.
Benefiting from the design freedom afforded by 3D printing, the researchers demonstrated they could tailor the flow in FTEs, dramatically improving mass transfer – the transport of liquid or gas reactants through the electrodes and onto the reactive surfaces. The work opens the door to establishing 3D printing as a “viable, versatile rapid-prototyping method” for flow-through electrodes and as a promising pathway to maximizing reactor performance, according to researchers.
University of Bath researchers have developed a graphene-based light material that can reduce aircraft engine noise and improve passenger comfort.
The graphene oxide-polyvinyl alcohol aerogel weighs just 2.1kg per cubic meter, making it the lightest sound insulation material ever manufactured. It could be used as insulation within aircraft engines to reduce noise by up to 16 decibels - reducing the 105-decibel roar of a jet engine taking off to a sound closer to that of a hair-dryer.
A collaborative research project between RISE SICOMP, GKN Aerospace Sweden, Nexam Chemical and Woxna Graphite, aimed to explore graphene-modified composites for long time- and high temperature applications, which can be used in aircraft components and other applications where the demands for durability are exceptionally high. The project took place August 20, 2019 – February 19, 2021.
Graphene was added as surface protection in the project, as a matrix modifier. Composites, with and without graphene, were manufactured and tested in the exact same way for comparison and reference.
Composed of aerogel graphene and two bio-inspired polymers, the novel material is reportedly capable of removing dyes, metals and organic solvents from drinking water with 100% efficiency. Unlike similar nanosheets, the scientists’ design is reusable, doesn’t leave residue and can be 3D printed into larger sizes. The team now plans to commercialize its design for industrial-scale deployment.