Aerogel Essay

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Definition Aerogel is defined as a group of extremely light and porous solid materials. Silica-based aerogels are among the lightest ones, can be less than four times as dense as dry air, and some are nearly transparent, its nickname is “solid smoke” or “frozen smoke”. Since this definition is good for most porous materials, the term aerogels became reserved for the porous gels obtained by removing solvent from highly swollen gels at the conditions that no or minimal collapse occurs, which causes the liquid in the gel to become supercritical (in a state between a liquid and a gas) and lose its surface tension. The result is an open porous material with a backbone morphology that can be modeled in terms of three dimensionally interconnected strings of nanoscopic pearls. The length scale of both the “pearls” as well as the interconnected voids can be independently tailored over a wide range, i.e. from a few nanometers to several microns.One of the striking advantages of aerogels compared to other porous materials is that both porosity and inner surface area can be tuned independently. Porosities of up to 99.9 % are achievable; when microporosity is present, the specific surface area can exceed 1500 m2/g. Because of their unique properties, i.e., large surface area, very small pores and very low bulk density, aerogels are potentially important candidates for a wide range of applications. Introduction: Steven. S. Kistler of the College of the Pacific in Stockton, California set out to prove that a "gel" contained a continuous solid network of the same size and shape as the wet gel. It is believed that Kistler's interest was stimulated by a friendly wager with fellow worker Charles Learned. They competed to see if one of them could replace the liquid inside a jelly jar with gas without causing any shrinkage. Kistler won the bet, and published his findings in a
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