World's lightest material: Scientists create carbon aerogel

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.