{"id":21315,"date":"2019-03-26T19:19:57","date_gmt":"2019-03-26T19:19:57","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=21315"},"modified":"2023-06-03T08:08:43","modified_gmt":"2023-06-03T08:08:43","slug":"aerogel","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/heat-transfer\/heat-losses\/insulation-materials\/aerogel\/","title":{"rendered":"Aerogel"},"content":{"rendered":"
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\"Aerogel<\/a>
A flower is on a piece of aerogel suspended over a flame from a Bunsen burner. Aerogel has excellent insulating properties, and the flower is protected from flame. Source: wikipedia.org License: Public Domain<\/figcaption><\/figure>\n

Aerogel<\/strong> is a synthetic porous ultralight solid material derived from a gel. The liquid component of the gel has been replaced with a gas (during a supercritical drying process). Aerogels<\/strong> can be made from various chemical compounds, but the base material for aerogel is usually silicon. Aerogel has a very low thermal conductivity of 0.013 W\/m\u2219K<\/strong>. Its density is also very low, about 150 kg\/m3<\/sup>. These are remarkable thermal insulative properties. It must be noted that aerogels may have lower thermal conductivity than the gas (air has about 0.025 W\/m\u2219K) they contain. This is caused by the Knudsen effect<\/strong>, a reduction of thermal conductivity in gases when the size of the cavity encompassing the gas becomes comparable to the mean free path<\/strong>.<\/p><\/div><\/div>

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<\/span>Categorization of Insulation Materials<\/div>
For insulation materials, three general categories can be defined. These categories are based on the chemical composition of the base material from which the insulating material is produced.\n

\"Insulation<\/a><\/p>\n

In further reading, there is a brief description of these types of insulation materials.<\/p>\n

Inorganic Insulation Materials<\/strong><\/p>\n

As can be seen from the figure, inorganic materials can be classified accordingly:<\/p>\n