Aerogel was invented by Kistler in 1931, and after more than 90 years, aerogel has broken 15 Guinness World Records for its excellent physical and chemical properties.

1. The Lowest Thermal Conductivity

The nanoscale micropores of aerogel suppress the contribution of gas molecules to heat conduction, and the thermal conductivity can be lower than 0.016W/(m-K). By means of doping, the radiative heat conduction of silica aerogel can be further reduced, and the thermal conductivity of carbon-doped aerogel at room temperature and pressure can be as low as 0.013W/(m-K), which is the solid-state material with the lowest thermal conductivity at present.

2. The Lowest Density

Aerogel has been listed as the lightest solid material in the Guinness Book of World Records. In recent years, this record is still being refreshed. In 2015, a nanofiber research team led by academician Yu Jianyong and Professor Ding Bin of Donghua University developed an ultra-light and ultra-elastic fiber aerogel using common fiber membrane materials, and the results of China’s metrology certification show that the solid material density of this fiber aerogel is only 0.12 mg/cm3, about 1/10 of the density of air.

3. The Widest Density Range

Due to different tissue compositions and production processes, the density of aerogel varies widely- its bulk density can be adjusted in the range of 0.0012-0.500g/m3. This gives aerogel materials a wider range of applications.

4. The Widest Compression Modulus

The compression modulus of aerogels can vary in a range of 6 orders of magnitude. Such a wide range of compression modulus determines the density adjustability of aerogel materials so that functional applications with different density requirements can be realized.

5. The Smallest Pore Size

The pore size of aerogel is generally concentrated around 50nm, and the smallest pore size can even be less than 1nm. Because of the fine nanoscale structure, the thermal conductivity of aerogel is extremely low, and the specific surface area is extremely large.

6. The Highest Porosity

The porosity of aerogel can be as high as 99.9%, and the numerous small pores on the surface make it ideal for adsorbing pollutants in water. Moreover, due to its exceptionally large specific surface area, aerogel has a wide application prospect as a new catalyst or catalyst carrier.

7. The Lowest Sound Propagation Speed

The porous network structure of aerogel gives it an ultra-low density, which makes the sound waves travel much slower in aerogel than in solid materials. Sound waves can travel as low as 70m/s inside the aerogel.

8. The Highest Acoustic Impedance

The acoustic impedance of aerogel is as high as 106kg/m2·s. The longitudinal sound propagation rate of aerogel is extremely low, while the acoustic resistance varies widely with the density, so it is an ideal material for acoustic impedance coupling.

9. The Lowest Dielectric Constant

With a dielectric constant of less than 1.003, aerogel is a good dielectric material that can reduce the leakage current of integrated circuits, reduce the capacitance effect between wires, reduce the heating of integrated circuits, etc.

10. The Lowest Refractive Index

Because of the extremely high proportion of air in aerogel, it has a very low refractive index—up to 1.0003, very close to that of air (1.0). This property has been applied by scientists to optical materials.

11. The Widest Refractive Index Range

The light transmittance of aerogel is very good, and the refractive index can be adjusted continuously from 1.0003 to 1.24 by adjusting the density of aerogel, which can be used to make detectors.

12. The Lowest Loss Angle Tangent

Aerogel has a very low loss angle tangent, and its loss angle tangent value is less than 10-4. So its wave permeability is very good, and it can be used as a good wave permeability material.

13. The Lowest Young’s modulus

Young’s modulus of aerogel is less than 106N/m2, which is four orders of magnitude lower than that of the corresponding non-porous glassy materials.

14. The First Sample Returned From a Comet

The first sample collected from a comet by humans was made using “aerogel gloves”. This precious material was returned to Earth on January 15, 2006, from Comet 2, and scientists are currently analyzing it to understand the chemical composition of this primitive ice body.

15. The Least Dense 3-D Printed Structure

A 3D-printed graphene aerogel developed in February 2016 by three researchers from Kansas State University and the University at Buffalo, the State University of New York (both USA), and Lanzhou University (China) has been named “the least dense 3-D printed structure” by Guinness World Records, with a density of only 0.5 mg/cm3.