Figure 1 Ablue silicon-based aerogel resting on whipped egg-white
Lawrence Livermore Laboratory/SPL
Aerogels, sometimes known as ‘frozen smoke’ (Figure 1), were invented in 1931. They are highly porous, solid foams with an interconnected network of thin walls and have very low density and thermal conductivity (Figure 2).
In May 2013, the journal Naturereported an aerogel with a density of 0.16 kg m –3, which is about one-seventh the density of air (1.2 kg m –3). The spacing of atoms in a solid is typically about one-tenth of their spacing in a gas, so you would expect even the lowest-density solid to be denser than air. For example, solid hydrogen has a density of 8.6 kg m–3.
Your organisation does not have access to this article.
Sign up today to give your students the edge they need to achieve their best grades with subject expertise
Subscribe
