The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform
Bruno Ameduri - One of the best experts on this subject based on the ideXlab platform.
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unique difference in transition temperature of two similar fluorinated side chain polymers forming hexatic smectic phase poly 2 perfluorooctyl ethyl acrylate and poly 2 perfluorooctyl ethyl vinyl ether
Macromolecules, 2014Co-Authors: Ryohei Ishige, Takamichi Shinohara, Kevin L White, Ahmed Meskini, Mustapha Raihane, Atsushi Takahara, Bruno AmeduriAbstract:The surface properties of comb-shaped polymers with perfluorooctyl ethyl side-chains are strongly related to the ordered Structure of the side-chains at the surface. In this work, the thermal behavior, Liquid-Crystalline Structure, and functional group orientation of comb-shaped polymers containing perfluorooctyl side-chains with poly(acrylate) (PFA-C8) and poly(vinyl ether) (PFAVE8) backbones are discussed based on DSC, synchrotron-source X-ray diffraction, and FTIR measurements. Despite the similar tilted hexatic smectic Structures and packing entropies, the isotropization temperature, Ti, of the PFA-C8 is significantly higher than the PFAVE8. Detailed characterization of the conformation, alignment, and organization of the perfluorooctyl side-chains indicate that the difference in Ti is related to the configuration of side-chains and interactions between the carbonyl groups along the acrylate backbone. The present findings show that the type of the linkage between the polymer backbone and fluorinated s...
Xiangkui Ren - One of the best experts on this subject based on the ideXlab platform.
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synthesis helical columnar Liquid Crystalline Structure and charge transporting property of perylene diimide derivative bearing oligosiloxane chains
Dyes and Pigments, 2018Co-Authors: Yang Zeng, Yakai Feng, Junfeng Zheng, Erqiang Chen, Tian Gao, Xiangkui RenAbstract:Abstract A novel perylene diimide (PDI) derivative bearing four oligosiloxane chains was synthesized. The phase behavior, self-assembly Structure and charge transport characteristic of the compound were elucidated via a sequence of experimental techniques such as UV/Vis and fluorescence spectra, differential scanning calorimetry, polarized optical microscopy, one- and two-dimensional X-ray diffraction as well as time-of-flight experiment. The experimental results reveal that the compound forms Liquid Crystalline (LC) helical supramolecular Structure with two molecules coupled side-by-side in each column stratum at room temperature. Due to this unique Structure, efficient charge transport occurs in the LC phase and the electron mobility reaches 1.5 × 10−3 cm2 V−1 s−1 at ambient temperature in spite of the large π-stack spacing in the column.
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ionic self assembled derivative of tetraphenylethylene synthesis enhanced solid state emission Liquid Crystalline Structure and cu2 detection ability
ChemPhysChem, 2017Co-Authors: Xiangkui Ren, Yakai Feng, Junfeng Zheng, Rui Liu, Xuqiang Jiang, Laiyao Geng, Erqiang ChenAbstract:A novel tetraphenylethylene complex composed of 4',4'',4''',4''''-(ethene-1,1,2,2-tetrayl)tetrabiphenyl-4-carboxylic acid (H4 ETTC) and dimethyldioctadecylammonium bromide (DOAB) with enhanced solid-state emission is designed and synthesized through an ionic self-assembly (ISA) strategy. The aggregation-induced emission property, phase behavior, and supramolecular Structure of the complex are characterized by a combination of experimental measurements. The experimental results reveal that the ISA complex can self-assemble into an ordered helical supramolecular Structure with enhanced luminescent properties, although the ETTC cores possess extensive conjugation and high rigidity. Due to the prolonged conjugation length, the fluorescence quantum yield of ETTC-DOAB is boosted to 66 %. Moreover, it is demonstrated that assemblies of the ISA complex are an effective sensor for Cu2+ . Owing to the disassembly modulation of ETTC-DOAB aggregations, the fluorescence emission of the assemblies can be selectively and sensitively quenched by Cu2+ , with a detection limit as low as 12.6 nm. The enhanced emission efficiency, in combination with the Liquid crystallinity and superior sensing performance to Cu2+ , make the ETTC-DOAB complex a potential candidate for the fabrication of a luminescent device and chemosensor for Cu2+ detection.
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synthesis aggregation induced emission and Liquid Crystalline Structure of tetraphenylethylene surfactant complex via ionic self assembly
Journal of Physical Chemistry C, 2016Co-Authors: Hui Jing, Yakai Feng, Junfeng Zheng, Liandong Deng, Erqiang Chen, Xiangkui RenAbstract:A novel tetraphenylethylene material with Liquid Crystalline (LC) helical Structure and aggregation-induced emission (AIE) property was prepared by ionic self-assembly (ISA). The AIE activity, phase behavior, self-assembly Structure, and molecular packing behavior of the complex were then elucidated via a combination of different experimental techniques such as UV–vis absorption spectra, photoluminescence spectra, differential scanning calorimetry, polarized optical microscopy, one- and two-dimensional X-ray diffraction, and Fourier transform infrared spectroscopy. The experimental results reveal that the ISA complex possesses high-efficiency luminescent property with quantum yield as high as 46% in solid state. Meanwhile, the complex could self-assemble into different interesting Structures which are sensitive to peripheral chain motions. During heating, the complex takes a low-ordered helical supramolecular Structure at ambient temperature and then forms another LC phase with high-ordered helical molecu...
Ryohei Ishige - One of the best experts on this subject based on the ideXlab platform.
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unique difference in transition temperature of two similar fluorinated side chain polymers forming hexatic smectic phase poly 2 perfluorooctyl ethyl acrylate and poly 2 perfluorooctyl ethyl vinyl ether
Macromolecules, 2014Co-Authors: Ryohei Ishige, Takamichi Shinohara, Kevin L White, Ahmed Meskini, Mustapha Raihane, Atsushi Takahara, Bruno AmeduriAbstract:The surface properties of comb-shaped polymers with perfluorooctyl ethyl side-chains are strongly related to the ordered Structure of the side-chains at the surface. In this work, the thermal behavior, Liquid-Crystalline Structure, and functional group orientation of comb-shaped polymers containing perfluorooctyl side-chains with poly(acrylate) (PFA-C8) and poly(vinyl ether) (PFAVE8) backbones are discussed based on DSC, synchrotron-source X-ray diffraction, and FTIR measurements. Despite the similar tilted hexatic smectic Structures and packing entropies, the isotropization temperature, Ti, of the PFA-C8 is significantly higher than the PFAVE8. Detailed characterization of the conformation, alignment, and organization of the perfluorooctyl side-chains indicate that the difference in Ti is related to the configuration of side-chains and interactions between the carbonyl groups along the acrylate backbone. The present findings show that the type of the linkage between the polymer backbone and fluorinated s...
Cesare Oliviero - One of the best experts on this subject based on the ideXlab platform.
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shear rheology and phase behaviour of sodium oleate water mixtures
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2007Co-Authors: Filipe E Antunes, Luigi Coppola, Danilo Gaudio, Isabella Nicotera, Cesare OlivieroAbstract:Abstract The knowledge of structural and dynamical properties in binary sodium oleate (NaO)/water mixtures represents a first step for studying new biocompatible Structures. In addition, a deeper understanding of their flow behaviour is crucial to control their mechanical properties. The purpose of this investigation was to revisit the binary NaO/water phase diagram through a combined effort of shear-rheology, NMR-diffusometry, optical polarizing microscopy and differential scanning calorimetry. The preparation of NaO/water mixtures in this work fitted with the interesting regions of the phase diagrams where most of the new systems will be prepared (i.e. from 0.01 to 30 wt.% NaO and within the temperature range 5–70 °C). Steady shear and linear viscoelastic experiments were accurately performed and the relationship between phase morphology and rheological properties was also studied. Regarding the mixtures at low surfactant concentrations, the shear flow showed: (1) a structural evolution into the Liquid micellar phase (L1) as a function of composition and (2) the presence of a viscous micellar region ( L 1 * ) induced by temperature and composition changes. NaO/water mixtures with a Liquid-Crystalline Structure (hexagonal H1) were studied by linear shear deformations and paying particular attention to frequency and temperature scans. Viscoelastic spectra of H1 phase presented a gel-like response which, although not expected, indicated the presence of a stiff Liquid-Crystalline lattice. Finally, a correlation between rheology and microstructural changes was conducted by the “weak-gel” model.
Erqiang Chen - One of the best experts on this subject based on the ideXlab platform.
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synthesis helical columnar Liquid Crystalline Structure and charge transporting property of perylene diimide derivative bearing oligosiloxane chains
Dyes and Pigments, 2018Co-Authors: Yang Zeng, Yakai Feng, Junfeng Zheng, Erqiang Chen, Tian Gao, Xiangkui RenAbstract:Abstract A novel perylene diimide (PDI) derivative bearing four oligosiloxane chains was synthesized. The phase behavior, self-assembly Structure and charge transport characteristic of the compound were elucidated via a sequence of experimental techniques such as UV/Vis and fluorescence spectra, differential scanning calorimetry, polarized optical microscopy, one- and two-dimensional X-ray diffraction as well as time-of-flight experiment. The experimental results reveal that the compound forms Liquid Crystalline (LC) helical supramolecular Structure with two molecules coupled side-by-side in each column stratum at room temperature. Due to this unique Structure, efficient charge transport occurs in the LC phase and the electron mobility reaches 1.5 × 10−3 cm2 V−1 s−1 at ambient temperature in spite of the large π-stack spacing in the column.
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ionic self assembled derivative of tetraphenylethylene synthesis enhanced solid state emission Liquid Crystalline Structure and cu2 detection ability
ChemPhysChem, 2017Co-Authors: Xiangkui Ren, Yakai Feng, Junfeng Zheng, Rui Liu, Xuqiang Jiang, Laiyao Geng, Erqiang ChenAbstract:A novel tetraphenylethylene complex composed of 4',4'',4''',4''''-(ethene-1,1,2,2-tetrayl)tetrabiphenyl-4-carboxylic acid (H4 ETTC) and dimethyldioctadecylammonium bromide (DOAB) with enhanced solid-state emission is designed and synthesized through an ionic self-assembly (ISA) strategy. The aggregation-induced emission property, phase behavior, and supramolecular Structure of the complex are characterized by a combination of experimental measurements. The experimental results reveal that the ISA complex can self-assemble into an ordered helical supramolecular Structure with enhanced luminescent properties, although the ETTC cores possess extensive conjugation and high rigidity. Due to the prolonged conjugation length, the fluorescence quantum yield of ETTC-DOAB is boosted to 66 %. Moreover, it is demonstrated that assemblies of the ISA complex are an effective sensor for Cu2+ . Owing to the disassembly modulation of ETTC-DOAB aggregations, the fluorescence emission of the assemblies can be selectively and sensitively quenched by Cu2+ , with a detection limit as low as 12.6 nm. The enhanced emission efficiency, in combination with the Liquid crystallinity and superior sensing performance to Cu2+ , make the ETTC-DOAB complex a potential candidate for the fabrication of a luminescent device and chemosensor for Cu2+ detection.
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synthesis aggregation induced emission and Liquid Crystalline Structure of tetraphenylethylene surfactant complex via ionic self assembly
Journal of Physical Chemistry C, 2016Co-Authors: Hui Jing, Yakai Feng, Junfeng Zheng, Liandong Deng, Erqiang Chen, Xiangkui RenAbstract:A novel tetraphenylethylene material with Liquid Crystalline (LC) helical Structure and aggregation-induced emission (AIE) property was prepared by ionic self-assembly (ISA). The AIE activity, phase behavior, self-assembly Structure, and molecular packing behavior of the complex were then elucidated via a combination of different experimental techniques such as UV–vis absorption spectra, photoluminescence spectra, differential scanning calorimetry, polarized optical microscopy, one- and two-dimensional X-ray diffraction, and Fourier transform infrared spectroscopy. The experimental results reveal that the ISA complex possesses high-efficiency luminescent property with quantum yield as high as 46% in solid state. Meanwhile, the complex could self-assemble into different interesting Structures which are sensitive to peripheral chain motions. During heating, the complex takes a low-ordered helical supramolecular Structure at ambient temperature and then forms another LC phase with high-ordered helical molecu...