A Foam lighter than Air- Aerogel

Aerogel is a very special type of foam which is 99.8% air. Aerogel is a low-density solid-state material derived from gel in which the liquid component of the gel has been replaced with gas. The result is an extremely low density solid with several remarkable properties, most notably its effectiveness as a thermal insulator. Aerogels are solid, but can be less dense then air. 

It was first invented in the 1930s by Samuel Stephens Kistler, but was very brittle and could not be shaped. Aerogels are traditionally expensive and difficult to manufacture, and they are difficult to handle. Now a team of scientists have discovered how to make it flexible so that it does not break so easily. This means there are a lot of ways in which it can be used to solve problems.

It is nicknamed frozen smoke, solid smoke or blue smoke due to its translucent nature and the way light scatters in the material; however, it feels like exploded polystyrene (Styrofoam) to the touch.

Aerogels posses the lowest density and highest internal surface area of any known solid material, which makes them extremely high performance material for collision, damping, acoustic and thermal insulation, structural support and surface chemistry.

Properties:

1. Extremely low density
2. Very good thermal insulator
3. High specific surface area
4. Lowest dielectric constant

Metal aerogel Properties:

1. High specific surface area (100-500m2/g)
2. Electrically conductive!
3. Enhanced catalytic activity
4. Surprisingly capable thermal insulator

Interesting Facts:

1. A paperclip has a mass of approximately one gram. A one gram sample of aerogel has an internal surface area of between 250 and 3000m2 per gram (when produced in a weightless environment).
2. Lowest solid density: The lightest man-made material is an Aerogel with a density of only three times the density of air. However industrial aerogels can be made denser, up to 0.6 g/cc or more.

1. Highest porosity: Perhaps the only material that can have over 95% porosity, and a very wide pore size distribution, ranging from Angstroms (10-10 meter) to microns (10-6 meter).
2. Very high surface area: For some Aerogels, one ounce can have a surface area equal to a football field (over 3000 square meters per one gram).
3. Versatile compositions: Aerogels can be made with a wide range of chemical compositions.
4. Functional properties by design: Combinations of the above features can lead to Aerogel materials with useful properties such as:
   • Adsorbents,
   • Catalysts,
   • Insulators,
   • Semiconductors,
   • Piezoelectric,
   • Dielectric,
   • Ferroelectric,
   • Diffusion controllers,
   • Electric conductors,
   • Electric insulators.
5. Can hold (theoretically) 500 to 4,000 times its weight in applied force.