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Laurent Gaillon - One of the best experts on this subject based on the ideXlab platform.

  • interfacial properties of mercury Ethylammonium Nitrate ionic liquid water system electrocapillarity surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

  • Interfacial properties of mercury/Ethylammonium Nitrate ionic liquid+water system: Electrocapillarity, surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/ EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance data indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

  • Interfacial properties of mercury/Ethylammonium Nitrate ionic liquid + water system: Electrocapillarity, surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

Malika Ammam - One of the best experts on this subject based on the ideXlab platform.

  • interfacial properties of mercury Ethylammonium Nitrate ionic liquid water system electrocapillarity surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

  • Interfacial properties of mercury/Ethylammonium Nitrate ionic liquid+water system: Electrocapillarity, surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/ EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance data indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

  • Interfacial properties of mercury/Ethylammonium Nitrate ionic liquid + water system: Electrocapillarity, surface charge and differential capacitance
    Electrochimica Acta, 2012
    Co-Authors: Malika Ammam, Dung Di Caprio, Laurent Gaillon
    Abstract:

    In this account, surface tensions of mercury/Ethylammonium Nitrate (EAN) aqueous solutions at different compositions as a function of the potential have been measured. Using the first and the second derivative of surface tension curves, surface charge and differential capacitance have been obtained. Assumptions based on simple hypotheses and comparison of the EAN behavior with respect to ammonium Nitrate (AN) provided information about the ionic structure at the interface mercury/EAN solutions. The results from the electrocapillarity maximum data suggest excess adsorption of the Nitrate anions at low EAN concentrations and excess adsorption of the Ethylammonium cations at higher concentrations. The results from the differential capacitance indicate that the ethyl group of the EAN cation would preferably be oriented towards the metal mercury.

Yukihiro Yoshimura - One of the best experts on this subject based on the ideXlab platform.

  • formation of α synuclein aggregates in aqueous Ethylammonium Nitrate solutions
    Biopolymers, 2020
    Co-Authors: Takahiro Takekiyo, Natsuki Yamada, Chikako T Nakazawa, Taku Amo, Atsushi Asano, Yukihiro Yoshimura
    Abstract:

    The effect of adding Ethylammonium Nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.

  • Formation of α‐synuclein aggregates in aqueous Ethylammonium Nitrate solutions
    Biopolymers, 2020
    Co-Authors: Takahiro Takekiyo, Natsuki Yamada, Chikako T Nakazawa, Taku Amo, Atsushi Asano, Yukihiro Yoshimura
    Abstract:

    The effect of adding Ethylammonium Nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.

  • Phase behavior of water-mediated protic ionic liquid: Ethylammonium Nitrate
    Journal of Molecular Liquids, 2017
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Akio Shimizu
    Abstract:

    Abstract In pure Ethylammonium Nitrate (EAN), which is a protic ionic liquid (pIL), multiple crystallization pathways are extracted by simultaneous X-ray diffraction and differential scanning calorimetry measurements. Multiple pathways for crystallization are selected by minimum temperatures in a pure EAN crystal. In an EAN – water system, phase equilibria are determined precisely by in situ observations made by using simultaneous measurements. Electrochemical instabilities induced by proton transfer are observed at 70  x 2 O [ Chem. Phys . 475 (2016) 119.]. Complicated phase diagrams indicate water-mediated anomalies as a crossover point from pIL-dominant to water-dominant regions.

  • electrochemical anomalies of protic ionic liquid water systems a case study using Ethylammonium Nitrate water system
    Chemical Physics, 2016
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Kazuya Nakama, Ryotaro Hayashi, Koji Saihara, Akio Shimizu
    Abstract:

    Abstract Electrochemical impedance spectroscopy was used to evaluate protic ionic liquid (pIL)-water mixtures in the temperature range of −35–25 °C. The pIL used in this study was Ethylammonium Nitrate (EAN). At room temperature, the resonant mode of conductivity was observed in the high frequency region. The anomalous conductivity disappeared once solidification occurred at low temperatures. The kinetic pH of the EAN-water system was investigated at a fixed temperature. Rhythmic pH oscillations in the EAN-H 2 O mixtures were induced at 70  x 2 O. The electrochemical instabilities in a EAN-water mixture are caused in an intermediate state between pIL and bulk water. From the ab initio calculations, it was observed that the dipole moment of the EAN-water complex shows a discrete jump at around 85 mol% H 2 O. Water-mediated hydrogen bonding network drastically changes at the crossover concentration.

  • Electrochemical anomalies of protic ionic liquid – Water systems: A case study using Ethylammonium Nitrate – Water system
    Chemical Physics, 2016
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Kazuya Nakama, Ryotaro Hayashi, Koji Saihara, Akio Shimizu
    Abstract:

    Abstract Electrochemical impedance spectroscopy was used to evaluate protic ionic liquid (pIL)-water mixtures in the temperature range of −35–25 °C. The pIL used in this study was Ethylammonium Nitrate (EAN). At room temperature, the resonant mode of conductivity was observed in the high frequency region. The anomalous conductivity disappeared once solidification occurred at low temperatures. The kinetic pH of the EAN-water system was investigated at a fixed temperature. Rhythmic pH oscillations in the EAN-H 2 O mixtures were induced at 70  x 2 O. The electrochemical instabilities in a EAN-water mixture are caused in an intermediate state between pIL and bulk water. From the ab initio calculations, it was observed that the dipole moment of the EAN-water complex shows a discrete jump at around 85 mol% H 2 O. Water-mediated hydrogen bonding network drastically changes at the crossover concentration.

Jingcheng Hao - One of the best experts on this subject based on the ideXlab platform.

  • Study of Ionic Liquid Microemulsions: Ethylammonium Nitrate/TritonX-100/Cyclohexane
    Tenside Surfactants Detergents, 2017
    Co-Authors: Liping Liu, Jingcheng Hao
    Abstract:

    Abstract In this study, ionic liquid (IL), specifically Ethylammonium Nitrate (EAN), was used instead of water to form nonaqueous microemulsions with cyclohexane and the nonionic surfactant Triton X-100 (TX-100). The phase behavior of the ternary system was investigated, and the microemulsions of ionic liquid-in-oil (IL/O) and oil-in-ionic liquid (O/IL) and the bicontinuous microregion were identified through traditional electrical conductivity measurement. The micropolarities of the IL/O microemulsions were determined via UV–Vis spectroscopy with methyl orange as an absorption probe. Results indicated that the polarity of the reverse micelles remained constant but that of the IL/O microemulsions increased when IL pools were formed. Fourier transform infrared spectroscopy was used to study the interaction mechanism between TX-100 and EAN molecules in IL/O microemulsions. We demonstrated that IL/O microemulsions may be promising for application due to the unique features of ILs and microemulsions.

  • study of ionic liquid microemulsions Ethylammonium Nitrate tritonx 100 cyclohexane
    Tenside Surfactants Detergents, 2017
    Co-Authors: Liping Liu, Jingcheng Hao
    Abstract:

    Abstract In this study, ionic liquid (IL), specifically Ethylammonium Nitrate (EAN), was used instead of water to form nonaqueous microemulsions with cyclohexane and the nonionic surfactant Triton X-100 (TX-100). The phase behavior of the ternary system was investigated, and the microemulsions of ionic liquid-in-oil (IL/O) and oil-in-ionic liquid (O/IL) and the bicontinuous microregion were identified through traditional electrical conductivity measurement. The micropolarities of the IL/O microemulsions were determined via UV–Vis spectroscopy with methyl orange as an absorption probe. Results indicated that the polarity of the reverse micelles remained constant but that of the IL/O microemulsions increased when IL pools were formed. Fourier transform infrared spectroscopy was used to study the interaction mechanism between TX-100 and EAN molecules in IL/O microemulsions. We demonstrated that IL/O microemulsions may be promising for application due to the unique features of ILs and microemulsions.

  • Ionogels of pseudogemini supra-amphiphiles in Ethylammonium Nitrate: Structures and properties.
    Journal of colloid and interface science, 2016
    Co-Authors: Xiaolin Wang, Zhuo Zhang, Yixue Cao, Jingcheng Hao
    Abstract:

    Abstract Thermoreversible ionogels formed by pseudogemini surfactants were prepared in protic ionic liquid, Ethylammonium Nitrate (EAN). Gemini-type supra-amphiphiles were formed by single-chain surfactants and bola-type molecules in a 2:1 M ratio. The structures of aggregates including polymorphous lamellar structures and fibrous networks constituted by multilayer lamellae were determined by optical microscopy observations, transmission electron microscopy (TEM) observations, small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) measurements. The mechanism of molecular arrangement in aggregates was proposed. Transformation temperatures of samples which are closely related to the stability of well-ordered molecules in aggregates, as well as the rheological properties of ionogels were investigated systematically. The work affords a new way to construct ionogel by using the supramolecular self-assembly of pseudogemini-type molecules, and brings new ideas for the future construction of ionogels.

  • Ionogels of Sugar Surfactant in Ethylammonium Nitrate: Phase Transition from Closely Packed Bilayers to Right-Handed Twisted Ribbons
    The journal of physical chemistry. B, 2015
    Co-Authors: Xiaolin Wang, Jingcheng Hao
    Abstract:

    In the simplest ionic liquid, Ethylammonium Nitrate (EAN), ionogels with high mechanical strength were prepared from a surfactant with a disaccharide polar head. Phase structures from closely packed bilayers to right-handed twisted ribbons were determined via freeze-fracture transmission electron microscopy (FF-TEM) observations. The phase transition mechanism was investigated deeply and systematically. The temperature contributes to suitable tail chain conformations of surfactant molecules for adapting to different self-assembled structures including right-handed twisted ribbons and bilayers. Two different arrays were revealed for different bilayers by the small-angle X-ray scattering (SAXS) measurements. The rheological and tribological properties of the ionogels were investigated. The better lubricating property and antiwear capability of the ionogels compared to the EAN may be attributed to the structure characteristics and the good thixotropic properties.

  • Ionogels of Sugar Surfactant in Ethylammonium Nitrate: Phase Transition from Closely Packed Bilayers to Right-Handed Twisted Ribbons
    2015
    Co-Authors: Xiaolin Wang, Jingcheng Hao
    Abstract:

    In the simplest ionic liquid, Ethylammonium Nitrate (EAN), ionogels with high mechanical strength were prepared from a surfactant with a disaccharide polar head. Phase structures from closely packed bilayers to right-handed twisted ribbons were determined via freeze-fracture transmission electron microscopy (FF-TEM) observations. The phase transition mechanism was investigated deeply and systematically. The temperature contributes to suitable tail chain conformations of surfactant molecules for adapting to different self-assembled structures including right-handed twisted ribbons and bilayers. Two different arrays were revealed for different bilayers by the small-angle X-ray scattering (SAXS) measurements. The rheological and tribological properties of the ionogels were investigated. The better lubricating property and antiwear capability of the ionogels compared to the EAN may be attributed to the structure characteristics and the good thixotropic properties

Takahiro Takekiyo - One of the best experts on this subject based on the ideXlab platform.

  • formation of α synuclein aggregates in aqueous Ethylammonium Nitrate solutions
    Biopolymers, 2020
    Co-Authors: Takahiro Takekiyo, Natsuki Yamada, Chikako T Nakazawa, Taku Amo, Atsushi Asano, Yukihiro Yoshimura
    Abstract:

    The effect of adding Ethylammonium Nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.

  • Formation of α‐synuclein aggregates in aqueous Ethylammonium Nitrate solutions
    Biopolymers, 2020
    Co-Authors: Takahiro Takekiyo, Natsuki Yamada, Chikako T Nakazawa, Taku Amo, Atsushi Asano, Yukihiro Yoshimura
    Abstract:

    The effect of adding Ethylammonium Nitrate (EAN), which is an ionic liquid (IL), on the aggregate formation of α-synuclein (α-Syn) in aqueous solution has been investigated. FTIR and Raman spectroscopy were used to investigate changes in the secondary structure of α-Syn and in the states of water molecules and EAN. The results presented here show that the addition of EAN to α-Syn causes the formation of an intermolecular β-sheet structure in the following manner: native disordered state → polyproline II (PPII)-helix → intermolecular β-sheet (α-Syn amyloid-like aggregates: α-SynA). Although cations and anions of EAN play roles in masking the charged side chains and PPII-helix-forming ability involved in the formation of α-SynA, water molecules are not directly related to its formation. We conclude that EAN-induced α-Syn amyloid-like aggregates form at hydrophobic associations in the middle of the molecules after masking the charged side chains at the N- and C-terminals of α-Syn.

  • Phase behavior of water-mediated protic ionic liquid: Ethylammonium Nitrate
    Journal of Molecular Liquids, 2017
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Akio Shimizu
    Abstract:

    Abstract In pure Ethylammonium Nitrate (EAN), which is a protic ionic liquid (pIL), multiple crystallization pathways are extracted by simultaneous X-ray diffraction and differential scanning calorimetry measurements. Multiple pathways for crystallization are selected by minimum temperatures in a pure EAN crystal. In an EAN – water system, phase equilibria are determined precisely by in situ observations made by using simultaneous measurements. Electrochemical instabilities induced by proton transfer are observed at 70  x 2 O [ Chem. Phys . 475 (2016) 119.]. Complicated phase diagrams indicate water-mediated anomalies as a crossover point from pIL-dominant to water-dominant regions.

  • electrochemical anomalies of protic ionic liquid water systems a case study using Ethylammonium Nitrate water system
    Chemical Physics, 2016
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Kazuya Nakama, Ryotaro Hayashi, Koji Saihara, Akio Shimizu
    Abstract:

    Abstract Electrochemical impedance spectroscopy was used to evaluate protic ionic liquid (pIL)-water mixtures in the temperature range of −35–25 °C. The pIL used in this study was Ethylammonium Nitrate (EAN). At room temperature, the resonant mode of conductivity was observed in the high frequency region. The anomalous conductivity disappeared once solidification occurred at low temperatures. The kinetic pH of the EAN-water system was investigated at a fixed temperature. Rhythmic pH oscillations in the EAN-H 2 O mixtures were induced at 70  x 2 O. The electrochemical instabilities in a EAN-water mixture are caused in an intermediate state between pIL and bulk water. From the ab initio calculations, it was observed that the dipole moment of the EAN-water complex shows a discrete jump at around 85 mol% H 2 O. Water-mediated hydrogen bonding network drastically changes at the crossover concentration.

  • Electrochemical anomalies of protic ionic liquid – Water systems: A case study using Ethylammonium Nitrate – Water system
    Chemical Physics, 2016
    Co-Authors: Hiroshi Abe, Masami Aono, Takahiro Takekiyo, Yukihiro Yoshimura, Kazuya Nakama, Ryotaro Hayashi, Koji Saihara, Akio Shimizu
    Abstract:

    Abstract Electrochemical impedance spectroscopy was used to evaluate protic ionic liquid (pIL)-water mixtures in the temperature range of −35–25 °C. The pIL used in this study was Ethylammonium Nitrate (EAN). At room temperature, the resonant mode of conductivity was observed in the high frequency region. The anomalous conductivity disappeared once solidification occurred at low temperatures. The kinetic pH of the EAN-water system was investigated at a fixed temperature. Rhythmic pH oscillations in the EAN-H 2 O mixtures were induced at 70  x 2 O. The electrochemical instabilities in a EAN-water mixture are caused in an intermediate state between pIL and bulk water. From the ab initio calculations, it was observed that the dipole moment of the EAN-water complex shows a discrete jump at around 85 mol% H 2 O. Water-mediated hydrogen bonding network drastically changes at the crossover concentration.