Some interesting properties and applications of aerogel, one of the lightest and best insulating materials in the world:
### 1. **Characteristics of Aerogel**
– **Physical properties**: Aerogel is a porous material with about 99% air and only 1% amorphous silica. This makes aerogel the best insulator, extremely effective at insulating, and the material with the lowest thermal conductivity.
– **Super hydrophobic properties**: When aerogel is broken down into dust, this dust can be applied to another surface, such as skin, making that surface completely hydrophobic. This allows the user to stay in water without getting wet, even after long immersion.
### 2. **Aerogel Applications**
– **Protection in harsh environments**: Aerogels are used by NASA to insulate spacecraft such as the Mars Rovers, demonstrating their ability to withstand harsh conditions.
– **Flexibility**: Although aerogels are brittle, a new version combining aerogels with closed-cell foam has been developed to reduce brittleness, making the material more versatile in many applications.
3. **Water Resistance Testing and Properties**
– **Water Test**: When aerogel powder is sprinkled on the surface of water, it does not sink but floats, forming a protective layer. If a match is placed in water containing aerogel, the match remains dry and can be lit.
– **Body coating test**: When the aerogel powder was coated on the body of a test subject, it not only kept the body dry when immersed in water, but also felt light, thanks to the layer of air between the skin surface and the water. This created a silvery light effect when viewed from the outside.
### 4. **Heat Resistance**
– **Protection against extremely low temperatures**: Aerogel was tested to resist liquid nitrogen, a substance with a temperature of about -196 degrees Celsius. When exposed to liquid nitrogen, the unprotected part froze and shattered, while the part protected by aerogel remained unaffected.
– **Comparison with other materials**: An experiment with cilantro showed that without the protective layer of aerogel, the vegetable would freeze and shatter when exposed to liquid nitrogen.
### 5. **Light Scattering Phenomenon**
– **Aerogel Color**: The nano-pores in aerogel are smaller than the wavelength of visible light (380-750 nanometers). Due to Rayleigh scattering, blue and violet light (with short wavelengths) are scattered more, making the aerogel appear blue.
– **Reaction to infrared light**: Conversely, infrared light with longer wavelengths can penetrate aerogel, making it appear transparent under those light conditions.
### 6. **Applications in Preservation**
– **Hygroscopic aerogel**: Some types of aerogel have the ability to absorb moisture from the air, helping to protect museum artifacts and store medicines without being damaged by moisture.
Aerogel is truly a miracle material with potential for wide-ranging applications in many fields.
