Difference between revisions of "Fumed silica"

Latest revision as of 11:48, 17 August 2023

Schematic of the production of fumed silica
Image Credit: Wikipedia

Description

[Degussa] A lightweight, fluffy white powder that is a colloidal form of Silica. Fumed silica, also called aerosol silica, is made by the combustion of silicon tetrachloride in a hydrogen-oxygen furnace. The tiny, amorphous, spherical particles fuse into three-dimensional secondary particles of varying sizes. The resulting powder has an extremely low bulk density and high surface area. Untreated fumed silica is hydrophilic, but many commercial products have been treated to make them hydrophobic. Generally, silanes or siloxanes are used to replace hydroxyl groups on the surface and thus prevent the absorption of moisture. Fumed silica is approved by the U.S. FDA for use in food products.

Synonyms and Related Terms

aerosol silica; colloidal silica; pyrogenic silica; thermal silica;

Commercial products: Aerosil® [Evonik]; Cab-O-Sil [Cabot]; HDK [Wacker Chemie]; Zandosil [Dow Corning]; Reolosil [Tokuyama Corp.]; Konasil [OCI]; Orisil [Orisil]; XYSIL [Xunyuchem]

Applications

Matting agent
Thickener
Filler
Desiccant to kill insects

Risks

Inhalation may cause silicosis; used dust mask.
Integra Chem: SDS

Physical and Chemical Properties

CAS = 112945-52-5
Composition = SiO2
Density = 2.0 - 2.2 g/cm3
Melting point = 1700 C
Decomposition = >2000C
Moisture content = 0.5-2.5 % (Hydrophilic); 0.5% (hydrophobic)
Adsorbed moisture = 6%
Refractive index = 1.46
Particle size = 5-40 nm

Resources and Citations

Wikipedia: Fumed silica Accessed July 2023
George Wypych, 'FILLERS – ORIGIN, CHEMICAL COMPOSITION, PROPERTIES, AND MORPHOLOGY, in Handbook of Fillers (Fourth Edition), 2016Chapter 2.1.79.1 Fumed Silica

@@ Line 1: / Line 1: @@
+[[File:Fumed silica process.png|thumb|Schematic of the production of fumed silica<br>Image Credit: [https://commons.wikimedia.org/wiki/File:Fumed_silica_process.svg  Wikipedia]]]
 == Description ==
-A colloidal form of silica that is a very light, fluffy white powder. Fumed silica, also called aerosol silica, is made by hydrogen-oxygen furnace combustion of silicon tetrachloride. This produces tiny spherical particles of varying sizes. Fumed silica is available in hydrophilic and hydrophobic (coated) forms. It is used as a matting agent, thickener, and filler in many adhesives and coatings. Fumed silica has also been used as a desiccating agent to kill insects.
+[Degussa] A lightweight, fluffy white powder that is a colloidal form of [[silica]]. Fumed silica, also called aerosol silica, is made by the combustion of silicon tetrachloride in a hydrogen-oxygen furnace. The tiny, amorphous, spherical particles fuse into three-dimensional secondary particles of varying sizes. The resulting powder has an extremely low bulk density and high surface area. Untreated fumed silica is hydrophilic, but many commercial products have  been treated to make them hydrophobic. Generally,  silanes or siloxanes are used to replace hydroxyl groups on the surface and thus prevent the absorption of moisture. Fumed silica is approved by the U.S. FDA for use in food products.
+== Synonyms and Related Terms ==
-== Synonyms and Related Terms ==
+aerosol silica; colloidal silica; pyrogenic silica; thermal silica;
+Commercial products: [[Aerosil|Aerosil®]] [Evonik]; [[Cab-O-Sil]] [Cabot]; HDK [Wacker Chemie]; Zandosil [Dow Corning]; Reolosil [Tokuyama Corp.]; Konasil [OCI]; Orisil [Orisil]; XYSIL [Xunyuchem]
+== Applications ==
+* Matting agent
+* Thickener
+* Filler
+* Desiccant to kill insects
+== Risks ==
-aerosol silica; colloidal silica; Aerosil® [Degussa-Huls]; Cab-O-Sil [Cabot]
+* Inhalation may cause silicosis; used dust mask.
+* Integra Chem: [https://www.integrachem.com/msds/S165_005.pdf SDS]
-{| class="wikitable"
+== Physical and Chemical Properties ==
-|-
-! scope="row"| CAS
-| 112945-52-5
-|}
-== Hazards and Safety ==
+* CAS = 112945-52-5
+* Composition = SiO2
+* Density = 2.0 - 2.2 g/cm3
+* Melting point = 1700 C
+* Decomposition = >2000C
+* Moisture content = 0.5-2.5 % (Hydrophilic); 0.5% (hydrophobic)
+* Adsorbed moisture = 6%
+* Refractive index = 1.46
+* Particle size = 5-40 nm
-Inhalation may cause silicosis; used dust mask.
+==Resources and Citations==
+* Wikipedia: [https://en.wikipedia.org/wiki/Fumed_silica Fumed silica] Accessed July 2023
+* George Wypych, 'FILLERS – ORIGIN, CHEMICAL COMPOSITION, PROPERTIES, AND MORPHOLOGY, in Handbook of Fillers (Fourth Edition), 2016Chapter 2.1.79.1 Fumed Silica
-Sigma Chemical: [http://siri.org/msds/f2/cjw/cjwkk.html MSDS]
 [[Category:Materials database]]