Advances in knowledge and technology have brought many changes to life, including the discovery of the latest materials. Have you ever thought about what is the lightest object or material in the world? Surely, people will answer carbon. Yes, indeed carbon is one of the lightest substances. However, carbon is a stronger material than steel. However, advances in science and the hard work of researchers have proven that there is the lightest material, namely aerogel. What is this? What are the facts surrounding this substance?
Aerogel Definition
This is a material that comes from combining solvent polymers. Furthermore, this polymer will form a gel with a very low-density level. It has a lower density than air. So it is clear that it is solid like a gel. So, how can this material be so light? The reason is, like gel in general which has liquid content inside, the liquid is no longer liquid but gas, making it very light.
Many studies write that it is a solid material with the lowest density level on earth. The density level is up to 1000 times looser than glass which has many applications in life. In conclusion, this artificial material has only 0.2% filled space out of 100%, the rest is just space.
The discovery of the material to what we see today has gone through many processes since its first creation in 1931 by an American chemist named Samuel Stephens Kistler. At first, aerogels were fragile and difficult to handle despite being solid materials. Their creation also required high costs, so people could not use them commercially. It was only for research needs in laboratories.
How is Aerogel Made?
Initially, the manufacture of this artificial material started by removing liquid from the gel without affecting the density of the structure. Logically, removing the liquid in the gel will directly damage the solid.
Then, the scientist who discovered the material first made it by modifying the gel-filling liquid, which was water, into alcohol. Then, it is evaporated under very critical conditions so that the liquid can dry without damaging its structure.
Conceptually, this material is generally made by extracting the liquid component from the gel and then replacing it with gas. The result is a solid substance but has a low density. As technology and knowledge develop, this material can be created by combining air and stiff foam. Initially, it was formed from a combination of silica, alumina, tin, chromium, and carbon.
Meanwhile, the manufacturing process is now more massive to meet commercial needs, although it still requires very high costs. The sol-gel method is a method for making this material and is commonly used for silica aerogels. However, aerogels can also be made from other materials, such as carbon or metal oxides. Modern advancements have led to the development of polymer-reinforced aerogels, which are more durable and suitable for a wider range of applications.
This method maintains product purity but works at low synthesis temperatures. This method involves the hydrophilic chemical sodium silicate. The next step is to synthesize silica by drying the SiO2 gel in carbon dioxide. The goal is to release a solvent that fills the pores of the gel without damaging the tissue. The result is aerogel as we recognize today. Even though the name is a gel, this material is not like gel in general. When touched, the surface is very similar to Styrofoam.
What are the Characteristics of This Material?
Maybe some of us have just heard what aerogel is. According to history, inventors discovered this material almost a hundred years ago. One of the most inherent characteristics of this material is that it is light, even lighter than steel, and has greater strength than metal. With only 60 grams, this material can support a person weighing 80 kg. That means this material can withstand loads 1000 times more than its weight. So, what are the other characteristics of material? Many industrial sectors utilize this material because it has the following properties:
- Low thermal conductivity
- Acts as a sound insulator
- Transparent
- Has the lowest density
- Elastic and light
- High surface area
So far, aerogel material has been used in many NASA projects and has played a role in missions to Mars. However, in everyday life, it is not too difficult to find applications. Examples of its application are insulators, portable coolers, and window glass because of their low thermal conductivity. There are many more applications for this substance, especially since the development of this material is getting better. We could find it in more sectors.