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Silica And A Solvent To Form A Gel

Feb 23

Silica aerogel has a remarkable range of physical properties which can be exploited for various applications in aerospace. It has the lowest density, thermal conductivity, refractive index, and dielectric constant among all solids and exhibits high acoustical properties. This remarkable material is used in spacecraft to capture hypervelocity particles and protect electronics during launch and reentry into the atmosphere. It has also been employed as an insulator in composite mats to provide protection for the primary battery pack of the Alpha Particle X-ray Spectrometer (APXS) on Mars Rovers. The capability to provide both fire and thermal insulation has given the material additional value in the aerospace industry.

The unique structure of Silica Aerogel in Insulation makes it a very lightweight material with the ability to trap large amounts of air. Silica aerogel is 95% porous, which provides a high surface area for a low mass density. The material can be fabricated into thin blankets to encapsulate and protect components such as pipes, wires, and electronic accessories within a fire zone in an aircraft. These blankets are able to withstand a continuous operating temperature of up to 1400°C and can be reshaped and cleaned to restore the function of the component after fire suppression. The thermal performance of silica aerogel is superior to conventional insulating materials such as fibreglass and mineral wool. The ability to withstand such a high temperature without damage has the potential to change the way that components are manufactured and stored in aircrafts. This will allow more parts to be placed together, resulting in a lighter and more compact design which can reduce assembly costs and increase the performance of the aircraft while reducing fuel consumption.

In the field of space exploration, a new application for the aerogel was recently developed by NASA and is now in use as an insulator for the Cherenkov detector in the Gamma Ray Observatory in Antarctica. The detection of cosmic rays requires a medium with a very low thermal conductivity to avoid unnecessary reflection. The use of silica aerogel in this application has the potential to dramatically lower the cost of the detector by allowing it to be produced with fewer materials.

Silica aerogels have also been utilized as a thermal insulator on the Mars Rover, Sojourner in 1997. The low-density of the material allowed it to absorb and convert the kinetic energy of the particles into heat, slowing them down to zero velocity. This technology has the potential to be expanded and developed for future outer space applications.

Aerogels are produced by combining silica and a solvent to form a gel. The gel is then subjected to supercritical fluid extraction. This involves introducing liquid carbon dioxide into the gel until it reaches its supercritical point and becomes a gas. This process is repeated many times until all the liquid has been removed. This is a time-consuming and expensive method to produce aerogel.

Researchers have been working on methods to speed up and improve the manufacturing process of aerogels. They have been exploring the possibility of using an atmospheric pressure drying process in order to decrease the preparation costs of this ultralight material. They have also been investigating different cross-linking techniques in order to improve the mechanical strength of aerogels. The addition of polymers such as diisocyanates into the microporous silica matrix has been shown to have dramatic effects on the material’s properties. This research is hoped to lead to the development of commercially viable silica aerogel products for a variety of aerospace applications.