Scientists create world's lightest material

Chinese scientists have developed the world's lightest substance - carbon aerogel - with a density only one sixth of that of the air.
Scientists at Zhejiang University produced the solid material which has a density of only 0.16 mg/cubic centimetre, breaking the previous record of the world's lightest material held by graphite aerogel.
The graphite aerogel was developed by German scientists last year with a density of 0.18 mg/cubic centimetre.
Aerogel is a material produced with semi-solid gel dried and solvent removed. It appears in a solid state with many internal pores filled with air, and thus it's of minimal density.

The research team led by Professor Gao Chao freeze-dried solutions of carbon nanotubes and graphene to remove moisture and retain integrity.
"Carbon aerogel is similar to carbon sponge in structure. When an aerogel of the size of a mug is put on Setaria, the slender grass will not bend," Gao Chao said in a statement.

Despite its fragile appearance, carbon aerogel is excellent in elasticity. It can bounce back when compressed.
In addition, it's one of the materials with biggest oil absorption capacity. Current oil absorbing products can usually absorb organic solvent of about 10 times of their own weight. The carbon aerogel newly developed can absorb up to 900 times their own weight.

"Carbon aerogel is expected to play an important role in pollution control such as oil spill control, water purification and even air purification," Gao Chao said.
In addition to pollution control, carbon aerogel is expected to become an ideal material for energy storage insulation, catalytic carrier and sound-absorption.
The study was published in the journal Advanced Materials.