Kinetics of alkoxysilanes hydrolysis: An empirical approach

<p>Alkoxysilanes and organoalkoxysilanes are primary materials in several industries, e.g. coating, anti-corrosion treatment, fabrication of stationary phase for chromatography, and coupling agents. The hydrolytic polycondensation reactions and final product can be controlled by adjusting the...

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محفوظ في:
التفاصيل البيبلوغرافية
المؤلف الرئيسي: Ahmed A. Issa (14152791) (author)
مؤلفون آخرون: Marwa El-Azazy (14152794) (author), Adriaan S. Luyt (14152341) (author)
منشور في: 2019
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author Ahmed A. Issa (14152791)
author2 Marwa El-Azazy (14152794)
Adriaan S. Luyt (14152341)
author2_role author
author
author_facet Ahmed A. Issa (14152791)
Marwa El-Azazy (14152794)
Adriaan S. Luyt (14152341)
author_role author
dc.creator.none.fl_str_mv Ahmed A. Issa (14152791)
Marwa El-Azazy (14152794)
Adriaan S. Luyt (14152341)
dc.date.none.fl_str_mv 2019-11-26T00:00:00Z
dc.identifier.none.fl_str_mv 10.1038/s41598-019-54095-0
dc.relation.none.fl_str_mv https://figshare.com/articles/journal_contribution/Kinetics_of_alkoxysilanes_hydrolysis_An_empirical_approach/21598137
dc.rights.none.fl_str_mv CC BY 4.0
info:eu-repo/semantics/openAccess
dc.subject.none.fl_str_mv Engineering
Chemical engineering
Materials engineering
Alkoxysilanes
Organoalkoxysilanes
Hydrolytic Polycondensation
Reaction Mechanisms
Catalysis
Solvent Properties
dc.title.none.fl_str_mv Kinetics of alkoxysilanes hydrolysis: An empirical approach
dc.type.none.fl_str_mv Text
Journal contribution
info:eu-repo/semantics/publishedVersion
text
contribution to journal
description <p>Alkoxysilanes and organoalkoxysilanes are primary materials in several industries, e.g. coating, anti-corrosion treatment, fabrication of stationary phase for chromatography, and coupling agents. The hydrolytic polycondensation reactions and final product can be controlled by adjusting the hydrolysis reaction, which was investigated under a variety of conditions, such as different alkoxysilanes, solvents, and catalysts by using gas chromatography. The hydrolysis rate of alkoxysilanes shows a dependence on the alkoxysilane structure (especially the organic attachments), solvent properties, and the catalyst dissociation constant and solubility. Some of the alkoxysilanes exhibit intramolecular catalysis. Hydrogen bonding plays an important role in the enhancement of the hydrolysis reaction, as well as the dipole moment of the alkoxysilanes, especially in acetonitrile. There is a relationship between the experimentally calculated polarity by the Taft equation and the reactivity, but it shows different responses depending on the solvent. It was found that negative and positive charges are respectively accumulated in the transition state in alkaline and acidic media. The reaction mechanisms are somewhat different from those previously suggested. Finally, it was found that enthalpy–entropy compensation (EEC) effect and isokinetic relationships (IKR) are exhibited during the hydrolysis of CTES in different solvents and catalysts; therefore, the reaction has a linear free energy relationship (LFER).</p><h2>Other Information</h2> <p> Published in: Scientific Reports<br> License: <a href="https://creativecommons.org/licenses/by/4.0" target="_blank">https://creativecommons.org/licenses/by/4.0</a><br>See article on publisher's website: <a href="http://dx.doi.org/10.1038/s41598-019-54095-0" target="_blank">http://dx.doi.org/10.1038/s41598-019-54095-0</a></p>
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identifier_str_mv 10.1038/s41598-019-54095-0
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oai_identifier_str oai:figshare.com:article/21598137
publishDate 2019
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spelling Kinetics of alkoxysilanes hydrolysis: An empirical approachAhmed A. Issa (14152791)Marwa El-Azazy (14152794)Adriaan S. Luyt (14152341)EngineeringChemical engineeringMaterials engineeringAlkoxysilanesOrganoalkoxysilanesHydrolytic PolycondensationReaction MechanismsCatalysisSolvent Properties<p>Alkoxysilanes and organoalkoxysilanes are primary materials in several industries, e.g. coating, anti-corrosion treatment, fabrication of stationary phase for chromatography, and coupling agents. The hydrolytic polycondensation reactions and final product can be controlled by adjusting the hydrolysis reaction, which was investigated under a variety of conditions, such as different alkoxysilanes, solvents, and catalysts by using gas chromatography. The hydrolysis rate of alkoxysilanes shows a dependence on the alkoxysilane structure (especially the organic attachments), solvent properties, and the catalyst dissociation constant and solubility. Some of the alkoxysilanes exhibit intramolecular catalysis. Hydrogen bonding plays an important role in the enhancement of the hydrolysis reaction, as well as the dipole moment of the alkoxysilanes, especially in acetonitrile. There is a relationship between the experimentally calculated polarity by the Taft equation and the reactivity, but it shows different responses depending on the solvent. It was found that negative and positive charges are respectively accumulated in the transition state in alkaline and acidic media. The reaction mechanisms are somewhat different from those previously suggested. Finally, it was found that enthalpy–entropy compensation (EEC) effect and isokinetic relationships (IKR) are exhibited during the hydrolysis of CTES in different solvents and catalysts; therefore, the reaction has a linear free energy relationship (LFER).</p><h2>Other Information</h2> <p> Published in: Scientific Reports<br> License: <a href="https://creativecommons.org/licenses/by/4.0" target="_blank">https://creativecommons.org/licenses/by/4.0</a><br>See article on publisher's website: <a href="http://dx.doi.org/10.1038/s41598-019-54095-0" target="_blank">http://dx.doi.org/10.1038/s41598-019-54095-0</a></p>2019-11-26T00:00:00ZTextJournal contributioninfo:eu-repo/semantics/publishedVersiontextcontribution to journal10.1038/s41598-019-54095-0https://figshare.com/articles/journal_contribution/Kinetics_of_alkoxysilanes_hydrolysis_An_empirical_approach/21598137CC BY 4.0info:eu-repo/semantics/openAccessoai:figshare.com:article/215981372019-11-26T00:00:00Z
spellingShingle Kinetics of alkoxysilanes hydrolysis: An empirical approach
Ahmed A. Issa (14152791)
Engineering
Chemical engineering
Materials engineering
Alkoxysilanes
Organoalkoxysilanes
Hydrolytic Polycondensation
Reaction Mechanisms
Catalysis
Solvent Properties
status_str publishedVersion
title Kinetics of alkoxysilanes hydrolysis: An empirical approach
title_full Kinetics of alkoxysilanes hydrolysis: An empirical approach
title_fullStr Kinetics of alkoxysilanes hydrolysis: An empirical approach
title_full_unstemmed Kinetics of alkoxysilanes hydrolysis: An empirical approach
title_short Kinetics of alkoxysilanes hydrolysis: An empirical approach
title_sort Kinetics of alkoxysilanes hydrolysis: An empirical approach
topic Engineering
Chemical engineering
Materials engineering
Alkoxysilanes
Organoalkoxysilanes
Hydrolytic Polycondensation
Reaction Mechanisms
Catalysis
Solvent Properties