Tetraethyl orthosilicate

99.999% trace metals basis

Orthosilicic acid tetraethyl ester, Silicon tetraethoxide, TEOS, Tetraethyl silicate, Tetraethoxysilane, Tetraethoxysilicon(IV)
Linear Formula:
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
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PubChem Substance ID:
Pricing and availability is not currently available.

vapor density

7.2 (vs air)

Quality Level

vapor pressure

<1 mmHg ( 20 °C)


99.999% trace metals basis



refractive index

n20/D 1.382 (lit.)


168 °C (lit.)


0.933 g/mL at 20 °C (lit.)

SMILES string




InChI key


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General description

Tetraethyl orthosilicate (TEOS) is an inorganic material used as a precursor for the synthesis of silica-based materials by methods such as sol gel technique, due to its high affinity to water. It can also be used in the synthesis of blended membranes.


TEOS is majorly used as a silicon source in the synthesis of silicon oxide which can be further used in a variety of optoelectronics based applications. It can also be used in the formation of hybrid coatings for potential usage in corrosion protection.
Commonly used as a precursor to prepare xerogel
Will interact with dodecylamine in the formation of intercalation compounds of H+-magadiite and used in a study of mixed-metal bioactive glasses.


25, 100 mL in glass bottle


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Hazard Statements

Target Organs

Respiratory system

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


UN1292 - class 3 - PG 3 - Tetraethyl silicate

WGK Germany


Flash Point(F)

113.0 °F - closed cup

Flash Point(C)

45 °C - closed cup

Development of hermetic barrier using vinyl triethoxysilane (VTEOS) and sol-gel processing
Jackson A, et al.
Material Matters, 1, 11-12 (2006)
Sol-Gel Science for Ceramic Materials
Young SK, et al.
Material Matters (2006)
Deposition of thick TEOS PECVD silicon oxide layers for integrated optical waveguide applications
Bulla DAP and Morimoto NI
Thin Solid Films, 334(1-2), 60-64 (1998)
Sol-gel-derived hybrid coatings for corrosion protection
Chou TP, et al.
Journal of Sol-Gel Science and Technology, 26(1-3), 321-327 (2003)
A performance evaluation of direct methanol fuel cell using impregnated tetraethyl-orthosilicate in cross-linked polymer membrane
Jung DH, et al.
International Journal of Hydrogen Energy, 26(12), 1263-1269 (2001)
From Form to Function: Molding Porous Materials in Three Dimensions by Colloidal Crystal Templating
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Research involving reactive silicone chemistry has focused on the production of pure silicon and hybrid materials, hydrosilylation, ring-opening and atom transfer polymerizations, polymerizations with controlled stereochemistry, and condensation reactions.
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Mesoporous Oxides and Their Applications to Hydrogen Storage
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Recent demand for electric and hybrid vehicles, coupled with a reduction in prices, has caused lithium-ion batteries (LIBs) to become an increasingly popular form of rechargeable battery technology.
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