ZnO as the Versatile Co-Catalyst for Oxygen-Tolerant External ATRP
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F23%3A63574658" target="_blank" >RIV/70883521:28610/23:63574658 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Alternative languages
Result language
angličtina
Original language name
ZnO as the Versatile Co-Catalyst for Oxygen-Tolerant External ATRP
Original language description
Zinc oxide (ZnO) is a remarkable semiconductor with piezoelectric and photocatalytic properties. For this reason, ZnO has often been used in mechanically controlled atom transfer radical polymerization (mechanoATRP), but its potential in photo-induced ATRP (photoATRP) remains underexplored. Previous works reported numerous limitations, including high oxygen sensitivity, tedious deoxygenation, ligands in stoichiometric excess to Cu, long polymerization times, and low yields.Herein, well-defined wurtzite ZnO nanocrystals were synthesized and employed as universal cocatalysts for mechano- and photoATRP of (meth)acrylates. Both techniques yielded polymers with excellent control over the molecular weight, but stimulation by photoirradiation resulted in much faster reactions, as compared to mechano-stimulation (conversion of91 % in 1 h vs. 54% in 5 h). We developed a method that makes ATRPs possible without prior deoxygenation, even in reactors with aerated headspace, since ZnO serves as a strong oxygen scavenger. Simultaneously, ZnO acted as an electron donor, reducing [Br-Cu(II)/Lt deactivators to [Cu(I)/Lt activators even in the absence of an excess ligand ( equimolar ligand to Cu ratio ). Co-catalyzed photoATRP was feasible with very low ZnO loadings (> 0.32 mg/mL), making ZnO one ofthe most potent heterogeneous catalysts for ATRP. The ZnO co-catalyzed photoATRP was tuned for excellent temporal control, and synthesized polymers exhibited high chain-end fidelity, as demonstrated by chain extension experiments. Finally, we present a novel concept for combining ZnO co-catalyzed mechano- and photoATRP techniques for facile ATRP workflow and better practicality.
Czech name
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Czech description
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Classification
Type
O - Miscellaneous
CEP classification
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OECD FORD branch
10404 - Polymer science
Result continuities
Project
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Continuities
V - Vyzkumna aktivita podporovana z jinych verejnych zdroju
Others
Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů