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However, material silica gel removes moisture by adsorption onto the surface of its numerous pores rather than by absorption into the bulk of the gel. Silica gel is able to adsorb up to 37% of its own weight in moisture in high-humidity environments. [7] This moisture can be released upon heating at about 120 °C (248 °F) [8] [7] for 1–2 ...
In contrast, silica gel can be regenerated by heating it in a regular oven to 120 °C (250 °F) for two hours. However, some types of silica gel will "pop" when exposed to enough water. However, some types of silica gel will "pop" when exposed to enough water.
Ormosils (organically modified silicate) are obtained when silane is added to gel-derived silica during sol–gel process. The product is a molecular-scale composite with improved mechanical properties. Sono-Ormosils are characterized by a higher density than classic gels as well as an improved thermal stability. An explanation therefore might ...
The Stöber process is a chemical process used to prepare silica (SiO 2) particles [1] of controllable and uniform size [2] for applications in materials science.It was pioneering [3] when it was reported by Werner Stöber and his team in 1968, [1] and remains today the most widely used wet chemistry synthetic approach to silica nanoparticles. [3]
In acidic solutions, the silicate ions react with hydrogen ions to form silicic acids, which tend to decompose into hydrated silicon dioxide gel. [citation needed] Heated to drive off the water, the result is a hard translucent substance called silica gel, widely used as a desiccant. It can withstand temperatures up to 1100 °C. [citation needed]
The three main classes of amorphous silica are pyrogenic silica, precipitated silica and silica gel. Among them, precipitated silica has the greatest commercial significance. In 1999, more than one million tons were produced, half of it is used in tires and shoe soles. [1] Like pyrogenic silica, precipitated silica is essentially not ...
The lowest-density silica nanofoam weighs 1,000 g/m 3, [58] which is the evacuated version of the record-aerogel of 1,900 g/m 3. [59] The density of air is 1,200 g/m 3 (at 20 °C and 1 atm). [60] The silica solidifies into three-dimensional, intertwined clusters that make up only 3% of the volume. Conduction through the solid is therefore very low.
Silica gel adsorber for NO 2, Fixed Nitrogen Research Laboratory, ca.1930s Silica gel is a chemically inert, non-toxic, polar and dimensionally stable (< 400 °C or 750 °F) amorphous form of SiO 2 . It is prepared by the reaction between sodium silicate and acetic acid, which is followed by a series of after-treatment processes such as aging ...