What does aerogel mean?
An aerogel is a remarkable synthetic material created by removing the liquid from a gel and replacing it with gas, leaving behind an extremely porous, ultralight solid. The result is often more than ninety-nine percent air by volume, giving it such low density that it has earned the evocative nickname 'frozen smoke.' Despite its airy structure, aerogel is a superb thermal insulator, resisting heat transfer far better than conventional materials, which makes it valuable in demanding applications: insulating pipelines, protecting buildings, and shielding spacecraft components from extreme temperatures. First developed in the early twentieth century, it remained largely a laboratory curiosity until advances in manufacturing made it commercially viable. Today the word appears chiefly in scientific, engineering, and aerospace writing, usually qualified by composition — silica aerogel and carbon aerogel are the most common varieties. For readers interested in materials science, 'aerogel' captures one of the most striking achievements of modern chemistry: a solid that behaves like trapped smoke.
nounA synthetic porous ultralight material in which the liquid component of a gel has been replaced with gas, without significant collapse of the gel structure. It is one of the lightest known solid materials and is an exceptionally effective thermal insulator.
- A synthetic porous ultralight material formed by replacing the liquid in a gel with gas, used chiefly as a thermal insulator.
"The spacecraft's dust collector used blocks of aerogel to capture particles from a comet's tail."
"Engineers lined the pipeline with aerogel to prevent heat loss in freezing conditions."
"Stardust's aerogel collector gently slowed and captured comet particles travelling at high speed."
The plural is standard when referring to different types or samples of the material; the singular is often used as an uncountable mass noun for the substance itself.
"Modern manufacturers produce aerogels based on silica, carbon, and polymers."
Nicknamed 'frozen smoke,' aerogel is over 99% air yet can withstand extreme heat — NASA uses it to insulate rovers on Mars.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of aerogel
The word 'aerogel' combines 'aero-', from Greek 'aēr' meaning air, with 'gel', a shortened form of 'gelatin'. It was coined in the early twentieth century by American chemist Samuel Kistler, who first produced the material in the late 1920s and early 1930s. The prefix 'aero-' also appears in words such as 'aerate' and 'aerodynamic', while 'gel' shares its origin with 'gelatin', both tracing back to Latin 'gelare', meaning to freeze or congeal.
How aerogel is actually used
A technical term used mainly in materials science, engineering, aerospace, and construction contexts; rarely encountered in everyday conversation. Often qualified by its chemical composition (e.g. silica aerogel, carbon aerogel).
Easily confused with aerogel
A gel is a soft, jelly-like substance containing liquid, whereas an aerogel is a rigid, dry solid whose liquid has been replaced by gas.