Upconversion-Nanoparticle-Assisted Radical Polymerization at λ =974 nm and the Generation of Acidic Cations
| Autor: | Ceren Kütahya, Bernd Strehmel, Dennis Oprych, Zhijun Chen, Si Wu, Chaoming Xie |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Materials science
010405 organic chemistry Organic Chemistry Radical polymerization UV filter 010402 general chemistry Chain termination Thioxanthone Photochemistry 01 natural sciences Photon upconversion 0104 chemical sciences Analytical Chemistry Photopolymer Polymerization Polymer chemistry Physical and Theoretical Chemistry Photoinitiator |
| Zdroj: | ChemPhotoChem. 1:499-503 |
| ISSN: | 2367-0932 |
| Popis: | Upconversion nanoparticles (UCNPs) sensitized photolytitic cleavage of the blue/UV photoinitiator bis(4-methoxybenzoyl) diethyl germanium (1). 1 initiated radical photopolymerization in combination with NaYF4:TmYb@NaYF4 UCNPs. A 974 nm NIR laser served as excitation source to generate blue and UV light. In addition, a metal free photo-ATRP system comprising (i-propyl) thioxanthone (ITX), N,N,N′,N′′,N′′-pentamethyldiethylenetriamine (PMDETA) and -bromo(i-butyl) ethylester (-BrBuEt)) was used instead of 1. This resulted in a significant smaller polydispersity compared to the UCNP/1 system. Control of polymerization was successfully proved by chain extension showing control of chain termination. For the first time, we demonstrated photolytic formation of acidic cations in such NIR UCNP-systems comprising an ITX/iodonium photoinitiator for sensitized generation of acidic cations. In addition, 1 also resulted in crosslinking of 1,6-hexanediol diacrylate (HDDA) in combination with UCNP and NIR-laser excitation. UV filter materials such as TiO2 do not significantly interfere crosslinking. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text