Despite the name, aerogels are solid, rigid, and dry materials that do not resemble a gel in their physical properties: the name comes from the fact that they are made from gels. Pressing softly on an aerogel typically does not leave even a minor mark; pressing more firmly will leave a permanent depression. Pressing extremely firmly will cause a catastrophic breakdown in the sparse structure, causing it to shatter like glass. Despite the fact that it is prone to shattering, it is very strong structurally. Its impressive load-bearing abilities are due to the dendritic microstructure, in which spherical particles of average size 2–5 nm are fused together into clusters. These clusters form a three-dimensional highly porous structure of almost fractal chains, with pores just under 100 nm. The average size and density of the pores can be controlled during the manufacturing process.
Aerogel is a material that is 99.8% air. Aerogels have a porous solid network that contains air pockets, with the air pockets taking up the majority of space within the material. The dearth of solid material allows aerogel to be almost weightless.
Aerogels are good thermal insulators because they almost nullify two of the three methods of heat transfer – conduction (they are mostly composed of insulating gas) and convection (the microstructure prevents net gas movement). They are good conductive insulators because they are composed almost entirely of gases, which are very poor heat conductors. (Silica aerogel is an especially good insulator because silica is also a poor conductor of heat. They are good convective inhibitors because air cannot circulate through the lattice.
Aerogel structure results from a sol-gel polymerization, which is when monomers (simple molecules) react with other monomers to form a sol or a substance that consists of bonded, cross-linked macromolecules with deposits of liquid solution among them. When the material is critically heated, the liquid evaporates and the bonded, cross-linked macromolecule frame is left behind.
What is Aerogel?
Why hasn't aerogel been used more broadly?
Satellites & Spacecrafts
Example of misunderstanding how to use aerogel
As technically the best insulator in the World, why hasn’t aerogels been taken up broadly in all sectors? This in fact highlights the reason for our existence.
Taking extreme performance products like Aerogel (and Graphene) and simply adding them to existing products and hoping to improve their performance levels will usually end in disappointment and failure.
Our experience has shown us that it is usually better to start from the Aerogel itself and build up the characteristics needed of the product around it. This obviously is not what most companies updating their products want to hear, so they explore adding on a product that has already been designed using aerogel and of course find the end result too expensive and often disappointing results.
An example of incorrect use is pictured to the left, where a Swiss manufacturer of aerated bricks make big claims about how much better their brick is by adding aerogel to the usually empty cells in the bricks. They then go on to report that this is an exciting R&D project but it doesn’t meet building regulations thermal standards for the UK and that it is currently way too expensive.
The reason why this use of aerogel fails is because they are not understanding the material and how it interacts with others. In this case they are using a glue to keep the crushed aerogel together and it is this interaction with this binding agent that causes the aerogel to fail; plus the structure of the brick has direct thermal bridging from one side to the other!
The uses for aerogels in the future are endless. In fact there are very few industries that couldn't benefit from it at some point. It will become an integrated part of all of our electronic consumable devices, our cars, planes, trains and our houses. Even furniture, carpets, packaging... the list could go on and on. Essentially if you could benefit from controlling temperature in your products, you are likely to want to use aerogel at some point soon.
The real jump in opportunities will come when we have understood more of the capabilities that can be derived from amalgamating different type of aerogels like ceramic with graphene. The characteristics are very different and therefore you design product performance during manufacture say in 3D printing (see picture above right).
Aerogels and graphene should shortly take over the battery market
Process for 3D printing a supercapacitor electrode with a graphene aerogel featuring manganese dioxide.
Where could aerogel go in the future?
Why is our Aerogel green?
Special permissions were granted for a large steam pipe to be installed between the WTE plant and the Aerogel partner's plant - the steam powers the aerogel production process.
The silica aerogel (KWARK) granules and powders have been fully characterised and are 100% amorphous (non – crystalline) silica and therefore safe.
Aerogel including blankets are recyclable.
Unlike many insulation materials – aerogel does not degrade over time and cannot be damaged by water – this long service life is a very important green credential.
At present the majority of the world’s insulation is based on petrochemical based chemicals and blowing agents such as Pentane – all very damaging to the environment.
These conventional insulations degrade over short periods of time – dramatically reducing the effectiveness of the insulation and releasing harmful CFC’s.
Aerogels can easily achieve an A1 Fire rating as they are essentially mineral in composition and are very light and highly breathable and do not release highly toxic chemicals such as Hydrogen Cyanide in the event of fire – unlike the majority of conventional petrochemical based insulation
Manufacturing process that captures carbon from Methane (The World’s worst and most prolific greenhouse gas).
Super insulates to reduce the amount of energy required to heat buildings/cars/planes.
A bi-product of production is Hydrogen gas which is the greenest heating gas on the planet.
- Ethanol produced from waste Methane gas
- Mix TEOS with Ethanol and water
- Sol – Gel Transition
- Ageing – finalisation of the 3D network (backbone)
- Hydrophobic treatment via silylation from amethyldisiloxane
- Drying at atmospheric pressure via microwave technology
All of these processes are fully patented by our Aerogel partner and chemicals are recycled throughout the process – The patented drying process is unique and highly energy efficient.
Tetraethyl orthosilicate (TEOS) is the source of silica for the aerogel backbone (the solid component of silica aerogel) – TEOS is a colourless liquid and is widely used in industry and is non toxic.
The Aerogel partner's plant is embedded within a chemical factory – part of which specialises in the manufacture of perfumes. The aerogel manufacturing process requires large quantities of pharmaceutical grade ethanol – the ethanol is available on site – no transportation required and existing safety measures are in place.
The majority of power needed is supplied via steam.
The Aerogel partner's plant is located directly opposite a state of the art - Waste To Energy (WTE) plant.