Aerogels are synthesized porous substances formed by substituting the liquid portion of a gel with a gaseous element while retaining its construction .Certain silica-based aerogels are practically transparent and weigh less than four times as much as dry air. Aerogels are fascinating due to their unique characteristics, which include exalted porosity (80–99.8 %), enormous surface area (500–1200 m2 g−1), and minimal density (0.003–0.5 g/cm3). Many types of aerogels exist, but they all share the characteristic of being porous solids with a surprising variety of unusual properties . Some exceptional physical features include low dielectric constant
, low refractive index, high thermal insulation, and solar light transmission
. Aerogels have also been referred to as “frozen smoke,” “solid smoke,” and “blue smoke”
Due to their unusual features, aerogels could be used for biomedical, acoustic, food packaging, electrochemical energy storage, thermal insulation, environmental, water treatment, catalysis and aerospace applications. Specifically pertinent for biomedical and pharmaceutical applications are aerogels based on silica, polymers, and hybrids, all of which exhibit remarkable permeability, biocompatibility, biodegradability, and capability to replicate organic constructions. Aerogels have numerous biomedical applications, including various diagnostic instruments, implantable devices, biosensing, wound repair, regenerative medicine, and delivery of medications
Aerogels enable the opportunity to combine effective heat insulation with favorable acoustic properties. Aerogel’s acoustic insulation and absorption depend significantly on the material preparation method, aerogel density, and pore formation. This diminishes the amplitude and speed of the sound waves, allowing them to decelerate and disperse more quickly. This could render aerogels suitable acoustic insulation materials .