Tetraethyl orthosilicate

packaged for use in deposition systems

Orthosilicic acid tetraethyl ester, Tetraethyl orthosilicate, Silicon tetraethoxide, Tetraethyl silicate, TEOS, Tetraethoxysilane, Tetraethoxysilicon(IV)
Linear Formula:
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:

vapor density

7.2 (vs air)

Quality Level

vapor pressure

<1 mmHg ( 20 °C)


≥99.5% (GC)



refractive index

n20/D 1.382 (lit.)


168 °C (lit.)


0.933 g/mL at 20 °C (lit.)

SMILES string




InChI key


Looking for similar products? Visit Product Comparison Guide


Tetraethyl orthosilicate (TEOS) is an oxygen containing precursor of Si used for the deposition of:
  • Si oxide
  • Oxycarbide
  • Doped silicate
  • Silanol
  • Siloxane polymer
  • Organosilicon thin films

The films can be deposited at low temperatues (<250 °C). TEOS is also used to deposit mesoporous and nanoporous thin films of silica. These porous films can be doped during deposition to further enhance their properties.
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 mL in stainless steel cylinder


FlameExclamation mark

Signal Word


Hazard Statements

Target Organs

Respiratory system


UN1292 - class 3 - PG 3 - Tetraethyl silicate

WGK Germany


Flash Point(F)

113.0 °F - closed cup

Flash Point(C)

45 °C - closed cup

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. Can the empty deposition cylinders be refilled?

    Yes, we are able to refill these cylinders through our SAFC Hitech group.  Please contact our Technical Service department by email at techserv@sial.com, and they will forward you to the appropriate SAFC Hitech representative for a quote.

  6. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

  7. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

Andreas Kay et al.
Journal of the American Chemical Society, 128(49), 15714-15721 (2006-12-07)
Thin films of silicon-doped Fe2O3 were deposited by APCVD (atmospheric pressure chemical vapor deposition) from Fe(CO)5 and TEOS (tetraethoxysilane) on SnO2-coated glass at 415 degrees C. HRSEM reveals a highly developed dendritic nanostructure of 500 nm thickness having a feature...
Seong Cheol Hong et al.
International journal of nanomedicine, 6, 3219-3231 (2012-01-13)
Superparamagnetic iron oxide nanoparticles (SPIONs) have been widely utilized for the diagnosis and therapy of specific diseases, as magnetic resonance imaging (MRI) contrast agents and drug-delivery carriers, due to their easy transportation to targeted areas by an external magnetic field....
Nils R Blumenthal et al.
Proceedings of the National Academy of Sciences of the United States of America, 111(45), 16124-16129 (2014-10-29)
Extracellular soluble signals are known to play a critical role in maintaining neuronal function and homeostasis in the CNS. However, the CNS is also composed of extracellular matrix macromolecules and glia support cells, and the contribution of the physical attributes...
Tom Hasell et al.
Advanced materials (Deerfield Beach, Fla.), 24(42), 5732-5737 (2012-08-30)
Macroscopic inorganic porous beads are imbibed with a "porous molecular additive" by simple solution processing techniques, resulting in controllable loading and increased surface area. The porous additive consists of soluble organic cage molecules that precipitate as microporous crystals when solutions...
Lin Lin et al.
Colloids and surfaces. B, Biointerfaces, 101, 97-100 (2012-07-17)
Hollow silica spheres with round mesoporous shells were synthesized by core-shell template method, using monodispersed cationic polystyrene particles as core, and TEOS (tetraethoxysilane) as the silica source to form shell. After calcination at 550°C, uniform spheres with a thin shell...

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service

Social Media

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon


Research. Development. Production.

We are a leading supplier to the global Life Science industry with solutions and services for research, biotechnology development and production, and pharmaceutical drug therapy development and production.

© 2021 Merck KGaA, Darmstadt, Germany and/or its affiliates. All Rights Reserved.

Reproduction of any materials from the site is strictly forbidden without permission.