A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Rational Selection of Cyanines as NIR-Sensitive Photoinitiating Systems up to 1000 nm Applied in Coating Sciences
A series of cyanines possessing varied terminal groups and substitutions were selected for the investigations into the relation between structural pattern of cyanines and their performance on initiation of free radical and/or cationic photopolymerization induced by near-infrared light, where cyanines served as photosensitizers and iodonium salts as co-initiators. The LEDs emitting between 750 nm-1000 nm exhibiting a high-power intensity of ≥ 1.0 W/cm2 were introduced for the excitation according to the absorption spectra of the absorbers. This technology of prototypes brings new impetus into the world of photochemistry under the photoinduced electron transfer (PET) reaction where these cyanines served as light sensitizers. The terminal patterns showed unexpectedly stronger impact than the substitutions at the main chain of the cyanines at specific positions regarding radiative deactivation by fluorescence emission and non-radiative deactivation upon exposure. A longer methine chain of the cyanine facilitates photobleaching in combination with iodonium salt. The open unbridged connecting methine chain shows higher reactivity regarding chemistry than bridged connecting chain. The terminal groups as presented by indolium, benzo[e]- and benzo[g]indolium resulted in photochemical reactions following a high efficiency to initiate photopolymerization, while benzo[c,d]-indolium-substitution of the terminal group favors the systems rather non-radiative deactivation facilitating to initiate thermally activated processes. The initiator system consisting of cyanine and iodonium salt could efficiently initiate free radical photopolymerization in the monomer of UDMA, TPGDA and TMPTA. Surprisingly, the combination of this initiator system could also sufficiently initiate the polymerization of 4-hydroxybutyl vinyl ether. Some cyanines based on heptamethine and nonamethine succeeded in the initiation of cationic photopolymerization using epoxides and oxetanes as monomers. In particular, a remarkably efficient initiation of ...
Rational Selection of Cyanines as NIR-Sensitive Photoinitiating Systems up to 1000 nm Applied in Coating Sciences
A series of cyanines possessing varied terminal groups and substitutions were selected for the investigations into the relation between structural pattern of cyanines and their performance on initiation of free radical and/or cationic photopolymerization induced by near-infrared light, where cyanines served as photosensitizers and iodonium salts as co-initiators. The LEDs emitting between 750 nm-1000 nm exhibiting a high-power intensity of ≥ 1.0 W/cm2 were introduced for the excitation according to the absorption spectra of the absorbers. This technology of prototypes brings new impetus into the world of photochemistry under the photoinduced electron transfer (PET) reaction where these cyanines served as light sensitizers. The terminal patterns showed unexpectedly stronger impact than the substitutions at the main chain of the cyanines at specific positions regarding radiative deactivation by fluorescence emission and non-radiative deactivation upon exposure. A longer methine chain of the cyanine facilitates photobleaching in combination with iodonium salt. The open unbridged connecting methine chain shows higher reactivity regarding chemistry than bridged connecting chain. The terminal groups as presented by indolium, benzo[e]- and benzo[g]indolium resulted in photochemical reactions following a high efficiency to initiate photopolymerization, while benzo[c,d]-indolium-substitution of the terminal group favors the systems rather non-radiative deactivation facilitating to initiate thermally activated processes. The initiator system consisting of cyanine and iodonium salt could efficiently initiate free radical photopolymerization in the monomer of UDMA, TPGDA and TMPTA. Surprisingly, the combination of this initiator system could also sufficiently initiate the polymerization of 4-hydroxybutyl vinyl ether. Some cyanines based on heptamethine and nonamethine succeeded in the initiation of cationic photopolymerization using epoxides and oxetanes as monomers. In particular, a remarkably efficient initiation of ...
Rational Selection of Cyanines as NIR-Sensitive Photoinitiating Systems up to 1000 nm Applied in Coating Sciences
Wang, Qunying (author) / Gutmann, Jochen S.
2024-02-02
Theses
Electronic Resource
English
| Wiley | 2009
Covalently bonded Camphorquinone - Amine Photoinitiating Systems
| British Library Conference Proceedings | 2003
| British Library Conference Proceedings | 2003
Reactions with Methylamine of Pyrilo-2-cyanines Containing Polyfluorophenyl Substituents
| British Library Online Contents | 2004
Synthesis and photoinitiating properties of N-substituted 2,6-diisopropylanilines
| British Library Online Contents | 2011