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Frédéric Dumur - One of the best experts on this subject based on the ideXlab platform.
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simultaneous initiation of radical and cationic polymerization reactions using the g1 Copper Complex as photoredox catalyst applications of free radical cationic hybrid photopolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Celine Dietlin, Haifaa Mokbel, R Plenderleith, D Anderson, Fabrice Morletsavary, Frédéric DumurAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic polymerization reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar Copper Complex and an anthracene derivative, dibutoxy anthracene), G1 showed better polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
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Mechanosynthesis of a Copper Complex for Redox Initiating Systems with a Unique Near Infrared Light Activation
Journal of Polymer Science Part A: Polymer Chemistry, 2017Co-Authors: Patxi Garra, Celine Dietlin, Frédéric Dumur, Fabrice Morlet-savary, Didier Gigmes, Jean-pierre Fouassier, Jacques LalevéeAbstract:The first use of a new mechanosynthesized Copper Complex (Cu(acac)(2dppba)) as a initiator for the redox and redox photoactivated polymerization of methacrylates under air is proposed. This paper (i) describes the mechanosynthesis of this Complex, (ii) outlines the relative efficiency of the Complex for redox polymerization (mechanosynthesized product vs. solvent synthesized product), (iii) follows the polymerization enhancement under a 405 nm light, and (iv) demonstrates the high performance of this Complex in near infrared photoactivated redox polymerization where a completely colorless polymer is obtained (unprecedented under NIR irradiations, 785 nm, here). The light activated polymerization exhibit higher conversions, better time controls (activation control) and higher surface conversions than redox polymerization. The mechanosynthesis is well characterized by two solvent-free methods (visual color change and Electron Spin Resonance) and two solvent-based methods (high resolution-electrospray ionization-mass spectrometry (HR-ESI-MS) and UV–vis spectrometry). The involved mechanisms are discussed. Mechanosynthesis of Copper Complexes opens new perspectives for Copper (photo)redox polymerization catalysts as the environmental impact and economical costs of the Complex synthesis are significantly reduced. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017
Celine Dietlin - One of the best experts on this subject based on the ideXlab platform.
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simultaneous initiation of radical and cationic polymerization reactions using the g1 Copper Complex as photoredox catalyst applications of free radical cationic hybrid photopolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Celine Dietlin, Haifaa Mokbel, R Plenderleith, D Anderson, Fabrice Morletsavary, Frédéric DumurAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic polymerization reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar Copper Complex and an anthracene derivative, dibutoxy anthracene), G1 showed better polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
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Mechanosynthesis of a Copper Complex for Redox Initiating Systems with a Unique Near Infrared Light Activation
Journal of Polymer Science Part A: Polymer Chemistry, 2017Co-Authors: Patxi Garra, Celine Dietlin, Frédéric Dumur, Fabrice Morlet-savary, Didier Gigmes, Jean-pierre Fouassier, Jacques LalevéeAbstract:The first use of a new mechanosynthesized Copper Complex (Cu(acac)(2dppba)) as a initiator for the redox and redox photoactivated polymerization of methacrylates under air is proposed. This paper (i) describes the mechanosynthesis of this Complex, (ii) outlines the relative efficiency of the Complex for redox polymerization (mechanosynthesized product vs. solvent synthesized product), (iii) follows the polymerization enhancement under a 405 nm light, and (iv) demonstrates the high performance of this Complex in near infrared photoactivated redox polymerization where a completely colorless polymer is obtained (unprecedented under NIR irradiations, 785 nm, here). The light activated polymerization exhibit higher conversions, better time controls (activation control) and higher surface conversions than redox polymerization. The mechanosynthesis is well characterized by two solvent-free methods (visual color change and Electron Spin Resonance) and two solvent-based methods (high resolution-electrospray ionization-mass spectrometry (HR-ESI-MS) and UV–vis spectrometry). The involved mechanisms are discussed. Mechanosynthesis of Copper Complexes opens new perspectives for Copper (photo)redox polymerization catalysts as the environmental impact and economical costs of the Complex synthesis are significantly reduced. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017
Haifaa Mokbel - One of the best experts on this subject based on the ideXlab platform.
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simultaneous initiation of radical and cationic polymerization reactions using the g1 Copper Complex as photoredox catalyst applications of free radical cationic hybrid photopolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Celine Dietlin, Haifaa Mokbel, R Plenderleith, D Anderson, Fabrice Morletsavary, Frédéric DumurAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic polymerization reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar Copper Complex and an anthracene derivative, dibutoxy anthracene), G1 showed better polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
Fabrice Morletsavary - One of the best experts on this subject based on the ideXlab platform.
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simultaneous initiation of radical and cationic polymerization reactions using the g1 Copper Complex as photoredox catalyst applications of free radical cationic hybrid photopolymerization in the composites and 3d printing fields
Progress in Organic Coatings, 2019Co-Authors: Celine Dietlin, Haifaa Mokbel, R Plenderleith, D Anderson, Fabrice Morletsavary, Frédéric DumurAbstract:Abstract This investigation presents the use of a photoredox catalyst "G1" as a photoinitiating system for free radical/cationic hybrid polymerization under mild irradiation conditions. The G1 system (G1/iodonium salt/N-vinylcarbazole), can simultaneously initiate the free radical and cationic polymerization reactions upon exposure to a visible (405 nm) light from a Light Emitting Diode (LED) source. The multicomponent G1 system is able to simultaneously generate radical and cationic species through a catalytic photoredox process. The curing of thin samples (25 μm), thick samples (1.4 mm) as well as the manufacture of hybrid system/glass fibers composites (˜2 to 4 mm thickness) was realized and the influence of the ratio of cationic/radical monomer blends on the polymerization kinetics was studied. The use of G1 in visible light photoinitiating system for the access to composites and 3D printing experiments was particularly outlined. G1 was also shown to have low levels of migration from the cured materials. When compared to reference materials ("F1", a similar Copper Complex and an anthracene derivative, dibutoxy anthracene), G1 showed better polymerization efficiency. The initiation efficiency was investigated through the real-time Fourier transform infrared (RT-FTIR) spectroscopy and optical pyrometry. Dynamical Mechanical Analysis has been used to determine the glass temperature transition of the cured hybrid system as a complementary technique.
Karine Loubière - One of the best experts on this subject based on the ideXlab platform.
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Using a bio-inspired Copper Complex to investigate reactive mass transfer around an oxygen bubble rising freely in a thin-gap cell
Chemical Engineering Science, 2019Co-Authors: Francisco Felis, Véronique Roig, Florian Strassl, Larissa Laurini, Nicolas Dietrich, Anne-marie Billet, Sonja Herres-pawlis, Karine LoubièreAbstract:The present study describes an original colorimetric method to visualize and quantify the local oxygen mass transfer around a rising bubble in reactive media. This method is based on the use of a colorless bio-inspired Copper Complex, Cu(btmgp)I, specially tailored for the study, which, dissolved in acetonitrile, oxidizes into an orange Copper-Complex [Cu2O2(btmgp)2]I2. The latter Complex, unstable at ambient temperature, decays quite fast into two Cu(II) Complexes, leaving a permanent pale-green color as final products. The flow investigated consists in a pure oxygen single bubble rising freely in a confined thin-gap cell (400 × 200 × 1 mm). A wide range of motion regimes for the bubbles are observed as the Archimedes number ranges from and the Reynolds number from . A high-resolution 16-bit sCMOS camera, combined with specific filters, is used to capture images from a region-of-interest of the cell, illuminated by a white LED backlight panel. An ad hoc calibration protocol is developed to correlate the grey-levels from the colored signal to the equivalent oxygen concentrations. This procedure then allows to measure indirectly the amount of oxygen transferred to the liquid phase. The series of images are also treated to identify the bubble motion and properties. Thanks to this method, equivalent oxygen concentration fields, gap-averaged and time-averaged, can be reached with high precision in the far-field wake of the bubbles, enabling thus to deeply characterize the mass transfer mechanisms under reactive conditions in such confined configuration, and to establish a dimensionless representation in terms of Sherwood number versus Peclet number. At last, thanks to the knowledge of the kinetic rate of the reaction and of the diffusion coefficients, the Hatta number and the enhancement factor are estimated, and thus the intrinsic Sherwood numbers; these results demonstrate that the enhancement of the mass transfer by the reactions involved with the Copper-Complexes is not negligible (almost 12–15%).