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An aerogel material can range from 50% to 99.98% air by volume, but in practice most aerogels exhibit somewhere between 90 and 99.8% porosity. [12] Aerogels have a porous solid network that contains air pockets, with the air pockets taking up the majority of space within the material. [13]
Aerographene or graphene aerogel is the least dense solid known to exist, at 160 g/m 3 (0.0100 lb/cu ft; 0.16 mg/cm 3; 4.3 oz/cu yd). [1] The material reportedly can be produced at the scale of cubic meters.
A xerogel is a solid that retains significant porosity (15-50%) with a very small pore size (1–10 nm). In an aerogel, the porosity is somewhat higher and the pores are more than an order of magnitude larger, resulting in an ultra-low-density material with a low thermal conductivity and an almost translucent, smoke-like appearance.
Porosity is a fraction between 0 and 1, typically ranging from less than 0.005 for solid granite to more than 0.5 for peat and clay. The porosity of a rock, or sedimentary layer, is an important consideration when attempting to evaluate the potential volume of water or hydrocarbons it may contain.
This creates a nanofoam, a foam with most of its bubbles under 100 nanometres in size, giving the aerogel its unusual properties: Silica aerogel is the lowest-density solid yet created, actually lighter than air when in a vacuum (outside of a vacuum, air fills the pores, upping its density to slightly greater than air). It is also the best ...
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. It is also very strong structurally, able to hold over 2000 times its own weight.
The sol–gel process is a wet-chemical technique used for the fabrication of both glassy and ceramic materials. In this process, the sol (or solution) evolves gradually towards the formation of a gel-like network containing both a liquid phase and a solid phase.
Silica aerogel: 0.02 [5] Silicon nitride: 90, [21] 177 [22] Ceramics material. Silver: ... 22% Porosity 2.3 [45] Constant 1000-1773 [45] This is number 54 on pages 73 ...