The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Christian Wohlfarth - One of the best experts on this subject based on the ideXlab platform.
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refractive index of 2 4 6 8 tetraethenyl 2 4 6 8 tetramethyl Cyclotetrasiloxane
2017Co-Authors: Christian WohlfarthAbstract:This chapter provides refractive index of 2,4,6,8-tetraethenyl-2,4,6,8-tetramethyl-Cyclotetrasiloxane at various temperatures and wavelengths.
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refractive index of binary liquid mixture of 1 3 dimethylbenzene and 2 4 6 8 tetraethenyl 2 4 6 8 tetramethyl Cyclotetrasiloxane
2017Co-Authors: Christian WohlfarthAbstract:This chapter provides refractive index of binary liquid mixture of 1,2-dimethylbenzene and 2,4,6,8-tetraethenyl-2,4,6,8-tetramethyl-Cyclotetrasiloxane at various temperatures and wavelengths.
Yong Qiu - One of the best experts on this subject based on the ideXlab platform.
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improved flame retardancy by synergy between Cyclotetrasiloxane and phosphaphenanthrene triazine compounds in epoxy thermoset
Polymer International, 2017Co-Authors: Yong Qiu, Patrick Klack, Volker Wachtendorf, Zhen Liu, Bernhard SchartelAbstract:A siloxane compound (MVC) and a bi-group phosphaphenanthrene/triazine compound (TGD) were employed in epoxy thermosets to explore high-efficiency flame retardant systems. With only 1wt% MVC and 3wt% TGD, an epoxy thermoset passed UL 94 V-0 rating test and achieved a limiting oxygen index value of 34.0%, exhibiting an excellent flame retardant effect. The MVC/TGD system not only decreased the peak value of heat release rate and effective heat of combustion but also imparted an improved charring ability to thermosets, thereby outstandingly reducing the flammability of 1%MVC/3%TGD/EP. Compared with the fire performance of 4%TGD/EP and 4%MVC/EP, the MVC/TGD system showed an obvious flame retardant synergistic effect, mainly depending on the general improvement of flame inhibition, charring and barrier effects of the thermoset during combustion. Evolved gas analysis combinedwith condensed-phase pyrolysis product Analysis jointly revealed the details of the changed pyrolysis mode.
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improved flame retardancy by synergy between Cyclotetrasiloxane and phosphaphenanthrene triazine compounds in epoxy thermoset
Polymer International, 2017Co-Authors: Yong Qiu, Patrick Klack, Volker Wachtendorf, Zhen Liu, Lijun Qian, Bernhard SchartelAbstract:A siloxane compound (MVC) and a bi-group phosphaphenanthrene/triazine compound (TGD) were employed in epoxy thermosets to explore high-efficiency flame retardant system. With only 1 wt.% MVC and 3 wt.% TGD, epoxy thermoset passed UL 94 V-0 rating test and achieved an limited oxygen index (LOI) value of 34.0%, which exhibited an excellent flame retardant effect. The MVC/TGD system not only decreased peak value of heat release rate and effective heat of combustion but also imposed the improved charring ability to thermosets, thereby outstandingly reducing the flammability of 1%MVC/3%TGD/EP. Compared with the fire performance of 4%TGD/EP and 4%MVC/EP, MVC/TGD system possessed obvious flame retardant synergistic effect, mainly depending on the general improvement of flame inhibition, charring, and barrier effects on thermoset during combustion. The evolved gas analysis combined with the condensed-phase pyrolysis product analysis jointly revealed the details of the changed pyrolysis mode.
Bernhard Schartel - One of the best experts on this subject based on the ideXlab platform.
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improved flame retardancy by synergy between Cyclotetrasiloxane and phosphaphenanthrene triazine compounds in epoxy thermoset
Polymer International, 2017Co-Authors: Yong Qiu, Patrick Klack, Volker Wachtendorf, Zhen Liu, Bernhard SchartelAbstract:A siloxane compound (MVC) and a bi-group phosphaphenanthrene/triazine compound (TGD) were employed in epoxy thermosets to explore high-efficiency flame retardant systems. With only 1wt% MVC and 3wt% TGD, an epoxy thermoset passed UL 94 V-0 rating test and achieved a limiting oxygen index value of 34.0%, exhibiting an excellent flame retardant effect. The MVC/TGD system not only decreased the peak value of heat release rate and effective heat of combustion but also imparted an improved charring ability to thermosets, thereby outstandingly reducing the flammability of 1%MVC/3%TGD/EP. Compared with the fire performance of 4%TGD/EP and 4%MVC/EP, the MVC/TGD system showed an obvious flame retardant synergistic effect, mainly depending on the general improvement of flame inhibition, charring and barrier effects of the thermoset during combustion. Evolved gas analysis combinedwith condensed-phase pyrolysis product Analysis jointly revealed the details of the changed pyrolysis mode.
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improved flame retardancy by synergy between Cyclotetrasiloxane and phosphaphenanthrene triazine compounds in epoxy thermoset
Polymer International, 2017Co-Authors: Yong Qiu, Patrick Klack, Volker Wachtendorf, Zhen Liu, Lijun Qian, Bernhard SchartelAbstract:A siloxane compound (MVC) and a bi-group phosphaphenanthrene/triazine compound (TGD) were employed in epoxy thermosets to explore high-efficiency flame retardant system. With only 1 wt.% MVC and 3 wt.% TGD, epoxy thermoset passed UL 94 V-0 rating test and achieved an limited oxygen index (LOI) value of 34.0%, which exhibited an excellent flame retardant effect. The MVC/TGD system not only decreased peak value of heat release rate and effective heat of combustion but also imposed the improved charring ability to thermosets, thereby outstandingly reducing the flammability of 1%MVC/3%TGD/EP. Compared with the fire performance of 4%TGD/EP and 4%MVC/EP, MVC/TGD system possessed obvious flame retardant synergistic effect, mainly depending on the general improvement of flame inhibition, charring, and barrier effects on thermoset during combustion. The evolved gas analysis combined with the condensed-phase pyrolysis product analysis jointly revealed the details of the changed pyrolysis mode.
William P Weber - One of the best experts on this subject based on the ideXlab platform.
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synthesis and characterization of octakis 3 3 3 trifluoropropyldimethylsiloxy Cyclotetrasiloxane i octakis tridecafluoro 2 2 5 5 tetramethyl 2 5 disilatridecanoxy Cyclotetrasiloxane ii and octakis 7 pentafluorophenyl 2 2 5 5 tetramethyl 2 5 disilahep
Journal of Fluorine Chemistry, 2004Co-Authors: Conan J Teng, Guoping Cai, William P WeberAbstract:Abstract Octakis(3,3,3-trifluoropropyldimethylsiloxy)Cyclotetrasiloxane ( I ), octakis[tridecafluoro-2,2,5,5-tetramethyl-2,5-disilatridecanoxy]Cyclotetrasiloxane ( II ), and octakis(7-pentafluorophenyl-2,2,5,5-tetramethyl-2,5-disilaheptanoxy)Cyclotetrasiloxane ( III ) have been prepared and characterized. Reaction of octakis[chloro calcium oxy]Cyclotetrasiloxane (Ca 8 Si 4 O 12 Cl 8 ) with 3,3,3-trifluoroproyldimethylchlorosilane yields I , II , and III , on the other hand, have been prepared by platinum catalyzed hydrosilylation reactions of octakis(vinyldimethylsiloxy)Cyclotetrasiloxane with tridecafluoro-1H,1H,2H,2H-octyldimethylsilane and 2-pentafluorophenyl-1H,1H,2H,2H-ethyldimethylsilane, respectively.
Masahiro Funahashi - One of the best experts on this subject based on the ideXlab platform.
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enhancement of spontaneous polarization and acid vapor induced polymerization in the thin film states of phenylterthiophene derivative bearing a Cyclotetrasiloxane ring
Crystals, 2020Co-Authors: Jumpei Nakagawa, Atsushi Seki, Masahiro FunahashiAbstract:We have achieved the measurement of spontaneous polarization of spin-coated thin films of a ferroelectric liquid crystal based on a phenylterthiophene skeleton. Uniaxially aligned spin-coated films with a thickness of 100 nm were prepared by the friction transfer method. The spontaneous polarization of the spin-coated films was measured by the Sawyer–Tower method and polarization inversion current technique under the application of triangular-wave bias. These measurements revealed the spontaneous polarization of 50 nC cm−2 in the thin-film state which is 1.5 times larger than the value of 35 nC cm−2 in the bulk state. This result should be attributed to the strong anchoring of the liquid-crystalline molecules on the substrate surface and the inhibition of polarization relaxation caused by the formation of the helical structure. Moreover, insolubilization of the thin films was carried out by an in situ ring-opening polymerization induced by acid vapors. The molecular alignment in the thin films of the ferroelectric liquid crystal was retained during the polymerization process.
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anisotropic electrical conductivity of n doped thin films of polymerizable liquid crystalline perylene bisimide bearing a triethylene oxide chain and Cyclotetrasiloxane rings
Materials Chemistry Frontiers, 2017Co-Authors: Masahiro FunahashiAbstract:A polymerizable liquid-crystalline perylene tetracarboxylic bisimide (PTCBI) derivative bearing a triethylene oxide chain and Cyclotetrasiloxane rings was synthesized. The compound exhibited a lamello-columnar phase in which the electron transport channels and ion-conductive sublayers were nanosegregated. Time-of-flight measurements revealed that the electron mobility of the columnar phase was on the order of 10−3 cm2 V−1 s−1. Thin films of the compound were produced by a spin-coating method, and the resulting films were polymerized and insolubilized via exposure to the vapors of trifluoromethanesulfonic acid. The uniaxially aligned thin films were doped in an aqueous solution of sodium dithionite. The electrical conductivity of the as-deposited and polymerized films increased to 10−4 S cm−1 in the doped states because ionic species can penetrate the ion-conductive sublayers. The anisotropy in the electrical conductivity of the as-deposited and polymerized thin films exceeds 100 and 10, respectively, in the doped states.
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in situ polymerization of liquid crystalline thin films of electron transporting perylene tetracarboxylic bisimide bearing Cyclotetrasiloxane rings
RSC Advances, 2016Co-Authors: Kaede Takenami, Shinobu Uemura, Masahiro FunahashiAbstract:A perylene tetracarboxylic bisimide (PTCBI) derivative bearing four Cyclotetrasiloxane rings that forms a columnar phase at room temperature despite the presence of the bulky Cyclotetrasiloxane rings was prepared. The electron mobility in the columnar phase of this PTCBI derivative at room temperature is 0.12 cm2 V−1 s−1, which is comparable to those of molecular crystals. The PTCBI derivative is soluble in various organic solvents and liquid crystalline thin films were successfully produced by a spin-coating method. The spin-coated films were insolubilized upon exposure to trifluoromethanesulfonic acid vapor. The columnar structure in the LC phase was retained during polymerization. Using a friction transfer method, macroscopically aligned LC thin films were produced and the optical anisotropy was retained after polymerization.
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liquid crystalline perylene tetracarboxylic bisimide derivatives bearing Cyclotetrasiloxane moieties
Journal of Materials Chemistry C, 2013Co-Authors: Masahiro Funahashi, Kaede Takenami, Mika Yamaoka, Akinari SonodaAbstract:Liquid-crystalline perylene tetracarboxylic bisimide derivatives bearing heptamethylCyclotetrasiloxane moieties have been synthesized. Compound 2 bearing four heptamethylCyclotetrasiloxane moieties exhibits a rectangular columnar phase at room temperature. In the columnar phase, the Cyclotetrasiloxane rings interdigitate into neighbouring columns and their interaction promotes the formation of the columnar mesomorphic structure. A time-of-flight measurement reveals that the electron mobility in the columnar phase of compound 2 is on the order of 10−2 cm2 V−1 s−1 at room temperature. Compound 2 is soluble in various organic solvents except for alcohol.
