Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Tetraethyl orthosilicate: Difference between pages

{{distinguish|Tetramethyl orthosilicate}}

| Verifiedfields = changed

| verifiedrevid = 470603747

| ImageFile1_Ref = {{chemboximage|correct|??}}

| ImageFile1 = Tetraethyl orthosilicate.svg

| ImageSize1 = 160px

| ImageFile2 = Tetraethyl orthosilicate 3D.png

| ImageSize2 = 200px

| IUPACName = Tetraethyl orthosilicate

| OtherNames = tetraethoxysilane; ethyl silicate, tetra-; silicic acid tetraethyl ester; silicon(IV) ethoxide; TEOS; tetraethyl silicate (ortho-)

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| CASNo_Ref = {{cascite|correct|CAS}}

| PubChem = 6517

| UNII_Ref = {{fdacite|changed|FDA}}

| UNII = 42064KRE49

| SMILES = CCO[Si](OCC)(OCC)OCC

|Section2={{Chembox Properties

| Formula = SiC₈H₂₀O₄

| MolarMass = 208.33{{nbsp}}g⋅mol⁻¹

| Appearance = Colourless liquid

| Odor = Sharp, alcohol-like<ref name=PGCH/>

| Density = 0.933{{nbsp}}g/mL at 20&nbsp;°C

| MeltingPtC = −77

| BoilingPtC = 168 to 169

| Solubility = Reacts with water, soluble in ethanol, and 2-propanol

| VaporPressure = 1{{nbsp}}mmHg<ref name=PGCH/>

|Section3={{Chembox Hazards

| MainHazards = Flammable, harmful by inhalation

| FlashPtC = 45

| AutoignitionPtC =

| PEL = TWA 100{{nbsp}}ppm (850{{nbsp}}mg/m³)<ref name=PGCH>{{PGCH|0282}}</ref>

| REL = TWA 10{{nbsp}}ppm (85{{nbsp}}mg/m³)<ref name=PGCH/>

| IDLH = 700{{nbsp}}ppm<ref name=PGCH/>

| LCLo = {{ubl

| 1000{{nbsp}}ppm (rat, 4{{nbsp}}hr)

| 700{{nbsp}}ppm (guinea pig, 6{{nbsp}}hr)

| 1740{{nbsp}}ppm (guinea pig, 15{{nbsp}}min)

| 1170 ppm (guinea pig, 2 hr)<ref name=IDLH>{{IDLH|78104|Ethyl silicate}}</ref>

}}

| LD50 = 6270{{nbsp}}mg/kg (rat, oral)<ref name=IDLH/>

'''Tetraethyl orthosilicate''', [[IUPAC Nomenclature of Inorganic Chemistry|formally named]] '''tetraethoxysilane''' ('''TEOS'''), '''ethyl silicate''' is the organic [[chemical compound]] with the [[chemical formula|formula]] Si(OC₂H₅)₄. TEOS is a colorless liquid. It degrades in water. TEOS is the {{Cl|ethyl esters|ethyl ester}} of [[Silicic acid|orthosilicic acid]], Si(OH)₄. It is the most prevalent [[alkoxide]] of silicon.

TEOS is a tetrahedral molecule. Like its many analogues, it is prepared by [[Solvolysis#Alcoholysis|alcoholysis]] of [[silicon tetrachloride]]:

:SiCl₄ + 4 EtOH → Si(OEt)₄ + 4 HCl

where Et is the [[ethyl group]], C₂H₅, and thus EtOH is [[ethanol]].

==Applications==

TEOS is mainly used as a crosslinking agent in [[silicone]] polymers and as a precursor to [[silicon dioxide]] in the semiconductor industry.<ref>{{cite journal|doi=10.1016/S0040-6090(98)01117-1|title=Deposition of thick TEOS PECVD silicon oxide layers for integrated optical waveguide applications|journal=Thin Solid Films|volume=334|pages=60–64|year=1998|last1=Bulla|first1=D.A.P|last2=Morimoto|first2=N.I|issue=1–2|bibcode = 1998TSF...334...60B }}</ref>

TEOS is also used as the silica source for synthesis of some [[zeolites]].<ref>Kulprathipanja, Santi (2010) ''Zeolites in Industrial Separation and Catalysis'', Wiley-VCH Verlag GmbH & Co. KGaA, {{ISBN|3527629572}}.</ref> Other applications include coatings for carpets and other objects. TEOS is used in the production of [[aerogel]]. These applications exploit the reactivity of the Si-OR bonds.<ref>Rösch, Lutz; John, Peter and Reitmeier, Rudolf "Silicon Compounds, Organic" in ''Ullmann's Encyclopedia of Industrial Chemistry'', Wiley-VCH, Weinheim, 2002. {{doi|10.1002/14356007.a24_021}}.</ref> TEOS has historically been used as an additive to alcohol based rocket fuels to decrease the heat flux to the chamber wall of regeneratively cooled engines by over 50%.<ref>{{Cite book|title=Ignition! An Informal History of Liquid Rocket Propellants|last=Clark|first=John D.|publisher=Rutgers University Press|year=1972|isbn=9780813507255|pages=105–106}}</ref>

TEOS is used in [[steel casting]] industry as an inorganic binder and stiffener for making silica-based [[ceramic molding]] forms (see also [[sodium silicate]]).<ref name=":0">{{Cite web |date=June 16, 2022 |title=Связующее Этилсиликат-40, каталог |trans-title=Ethylsilicate 40 binder |url=https://www.himprom.com/products/svyazuyushchee-etilsilikat-40-gost/ |access-date=2022-06-16 |website=www.himprom.com |publisher=ПАО Химпром}}</ref><ref name=":1">{{Cite web |date=June 16, 2022 |title=Связующее Этилсиликат-32, каталог |trans-title=Ethylsilicate 32 binder |url=https://www.himprom.com/products/svyazuyushchee-etilsilikat-32/ |access-date=2022-06-16 |website=www.himprom.com |publisher=ПАО Химпром}}</ref>{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

As inorganic binder for coatings ([[Passivation (chemistry)|passivation]]) of different materials such as steel, glass, brass, and even wood in order to make surfaces water-, oxygen- and high-temperature resistant.<ref name=":0" /><ref name=":1" />{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

As additive to solid polymers to enhance adhesiveness to glass, steel or wood.<ref name=":0" /><ref name=":1" />{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

As a binder for porcelain [[Crown (tooth)|teeth crowns]].<ref name=":2">{{Cite web |date=June 16, 2022 |title=Тетраэтоксисилан, каталог |trans-title=Tetraethoxysilane, catalogue |url=https://www.himprom.com/products/tetraetoksisilan/ |access-date=2022-06-16 |website=www.himprom.com |publisher=ПАО Химпром}}</ref>{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

As precursor to [[siloxane]]s.<ref name=":2" />{{Better source needed|reason=The current source is insufficiently reliable ([[WP:NOTRS]]).|date=June 2022}}

==Other reactions==

TEOS easily converts to [[silicon dioxide]] upon the addition of water:

:Si(OC₂H₅)₄ + 2 H₂O → SiO₂ + 4 C₂H₅OH

An idealized equation is shown, in reality the silica produced is hydrated. This hydrolysis reaction is an example of a [[sol-gel]] process. The side product is ethanol. The reaction proceeds via a series of condensation reactions that convert the TEOS molecule into a mineral-like solid via the formation of Si-O-Si linkages. Rates of this conversion are sensitive to the presence of [[acid]]s and bases, both of which serve as [[catalyst]]s. The [[Stöber process]] allows the formation of [[monodisperse]] and [[mesoporous silica]].<ref>{{cite book|chapter = Functionalization of Silica Nanoparticles for Corrosion Prevention of Underlying Metal|first1 = Dylan J.|last1 = Boday|first2 = Jason T.|last2 = Wertz|first3 = Joseph P.|last3 = Kuczynski|pages = 121–140|title = Nanomaterials, Polymers and Devices: Materials Functionalization and Device Fabrication|editor-first = Eric S. W.|editor-last = Kong|publisher = [[John Wiley & Sons]]|year = 2015|isbn = 9781118866955|chapter-url = https://books.google.com/books?id=djhPCAAAQBAJ&dq=St%C3%B6ber+process&pg=PA131}}</ref><ref>{{cite book|chapter = Nanoparticles and Composites|first = Guido|last = Kicklebick|pages = 227–244|title = The Sol-Gel Handbook: Synthesis, Characterization and Applications|volume = 3|editor1-first = David|editor1-last = Levy|editor2-first = Marcos|editor2-last = Zayat|publisher = [[John Wiley & Sons]]|year = 2015|isbn = 9783527334865|chapter-url = https://books.google.com/books?id=9ZSbCgAAQBAJ&dq=St%C3%B6ber+process&pg=PA229}}</ref><ref name = Berg>{{cite book|title = An Introduction to Interfaces and Colloids: The Bridge to Nanoscience|first = John C.|last = Berg|publisher = [[World Scientific Publishing]]|year = 2009|isbn = 9789813100985|pages = 367–368, 452–454|chapter-url = https://books.google.com/books?id=nmZIDQAAQBAJ&dq=St%C3%B6ber+process&pg=PA367|chapter = Colloidal Systems: Phenomenology and Characterization}}</ref>

At elevated temperatures (>600&nbsp;°C), TEOS converts to [[silicon dioxide]]:

:Si(OC₂H₅)₄ → SiO₂ + 2 (C₂H₅)₂O

The volatile coproduct is [[diethyl ether]].

==Safety==

Inhalation of TEOS induces eye and nose irritation, and eye contact with the liquid is irritating. High exposure to TEOS can lead to [[pulmonary edema]], but hazards can be reduced by atmospheric humidity and vapor pressure conditions.<ref>{{Cite web |last=PubChem |title=Ethyl silicate |url=https://pubchem.ncbi.nlm.nih.gov/source/hsdb/534 |access-date=2024-05-15 |website=pubchem.ncbi.nlm.nih.gov |language=en}}</ref> The mechanism of irritation is similar to that of [[tetramethyl orthosilicate]].

== References ==

<references/>

==External links==

*[http://webbook.nist.gov/cgi/cbook.cgi?ID=C78104 NIST Standard Reference Database 69, June 2005 Release: NIST Chemistry WebBook]

*[https://www.cdc.gov/niosh/npg/npgd0282.html CDC – NIOSH Pocket Guide to Chemical Hazards]

[[Category:Ethoxy compounds]]

[[Category:Silicate esters]]