Aerosil
Encyclopedia
Aerosil is a registered trademark for fumed silica
product developed in 1942 by Degussa AG (currently Evonik Industries
) in Germany.
, made from vaporized silicon tetrachloride
oxidized in high-temperature flame with hydrogen
and oxygen
.
Aggregated amorphous nano-sized primary particles
gives free flow to powder materials. It gives thickening
effect and thixotropy
by dispersing to liquid materials.
Standard hydrophilic products are made of primary particles from 7 nm to 40 nm, and also these products are surface modified to hydrophobic.
Fumed silica
Fumed silica, also known as pyrogenic silica because it is produced in a flame, consists of microscopic droplets of amorphous silica fused into branched, chainlike, three-dimensional secondary particles which then agglomerate into tertiary particles. The resulting powder has an extremely low bulk...
product developed in 1942 by Degussa AG (currently Evonik Industries
Evonik Industries
Evonik Industries is an industrial corporation in Germany owned by RAG Foundation and one of the world´s leading specialty chemicals companies. It was created on 12 September 2007 as a result of restructuring of the mining and technology group RAG...
) in Germany.
Properties
Aerosil is pure silicon dioxideSilicon dioxide
The chemical compound silicon dioxide, also known as silica , is an oxide of silicon with the chemical formula '. It has been known for its hardness since antiquity...
, made from vaporized silicon tetrachloride
Silicon tetrachloride
Silicon tetrachloride is the inorganic compound with the formula SiCl4. It is a colourless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications.-Preparation:...
oxidized in high-temperature flame with hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
.
Aggregated amorphous nano-sized primary particles
Nanoparticle
In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. Particles are further classified according to size : in terms of diameter, coarse particles cover a range between 10,000 and 2,500 nanometers. Fine particles are sized...
gives free flow to powder materials. It gives thickening
Thickening agent
Thickening agents, or thickeners, is the term applied to substances which increase the viscosity of a solution or liquid/solid mixture without substantially modifying its other properties; although most frequently applied to foods where the target property is taste, the term also is applicable to...
effect and thixotropy
Thixotropy
Thixotropy is the property of certain gels or fluids that are thick under normal conditions, but flow over time when shaken, agitated, or otherwise stressed...
by dispersing to liquid materials.
Standard hydrophilic products are made of primary particles from 7 nm to 40 nm, and also these products are surface modified to hydrophobic.
Applications
- As free-flow agentAnticaking agentAn anticaking agent is an additive placed in powdered or granulated materials, such as table salt, to prevent the formation of lumps, easing packaging, transport, and consumption....
: tonerTonerToner is a powder used in laser printers and photocopiers to form the printed text and images on the paper. In its early form it was simply carbon powder. Then, to improve the quality of the printout, the carbon was melt-mixed with a polymer...
s, foods, pharmaceuticals, biological weaponshttp://www.ph.ucla.edu/epi/bioter/fbitheorydoubted.html - As food rheologyFood rheologyFood rheology is the study of the rheological properties of food, that is, the consistency and flow of food under tightly specified conditions. The consistency, degree of fluidity, and other mechanical properties are important in understanding how long food can be stored, how stable it will...
controller: paintPaintPaint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...
s, coatingCoatingCoating is a covering that is applied to the surface of an object, usually referred to as the substrate. In many cases coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance...
s, adhesiveAdhesiveAn adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
s, sealantSealantA sealant may be viscous material that has little or no flow characteristics and stay where they are applied or thin and runny so as to allow it to penetrate the substrate by means of capillary reaction...
s, plastics. - Others: film, fiber, ceramics, catalyst supportCatalyst supportIn chemistry, a catalyst support is the material, usually a solid with a high surface area, to which a catalyst is affixed. The reactivity of heterogeneous catalysts occurs at the surface atoms. Consequently great effort is made to maximize the surface area of a catalyst by distributing it over...
, glassGlassGlass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
.