The Experts below are selected from a list of 36672 Experts worldwide ranked by ideXlab platform
Eugene Mamontov - One of the best experts on this subject based on the ideXlab platform.
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humidity exposure enhances microscopic mobility in a room temperature ionic liquid in mxene
Journal of Physical Chemistry C, 2018Co-Authors: Naresh C Osti, Matthew Thompson, Katherine L Van Aken, Mohamed Alhabeb, Madhusudan Tyagi, Jongkahk Keum, Peter T Cummings, Yury Gogotsi, Eugene MamontovAbstract:Present and future electrochemical devices employing advanced electrode and electrolyte materials are expected to operate in diverse environments, where they are exposed to variable conditions, such as changing humidity levels. Such conditions can possibly alter the microscopic mechanisms that influence the electrochemical performance. Here, using quasi-elastic neutron scattering and molecular dynamics simulations, we investigate the influence of humidity exposure on a room-temperature ionic liquid, [EMIm+][Tf2N–], in Ti3C2Tx MXene. Absorbed Water enhances the microscopic mobility of confined [EMIm+][Tf2N–], even though the ionic liquid itself is not very hygroscopic. The Absorbed Water molecules predominantly reside on the termination groups of the more hydrophilic MXene layers, thereby displacing the ions from the surface and facilitating their motions in the MXene matrix.
Madhusudan Tyagi - One of the best experts on this subject based on the ideXlab platform.
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humidity exposure enhances microscopic mobility in a room temperature ionic liquid in mxene
Journal of Physical Chemistry C, 2018Co-Authors: Naresh C Osti, Matthew Thompson, Katherine L Van Aken, Mohamed Alhabeb, Madhusudan Tyagi, Jongkahk Keum, Peter T Cummings, Yury Gogotsi, Eugene MamontovAbstract:Present and future electrochemical devices employing advanced electrode and electrolyte materials are expected to operate in diverse environments, where they are exposed to variable conditions, such as changing humidity levels. Such conditions can possibly alter the microscopic mechanisms that influence the electrochemical performance. Here, using quasi-elastic neutron scattering and molecular dynamics simulations, we investigate the influence of humidity exposure on a room-temperature ionic liquid, [EMIm+][Tf2N–], in Ti3C2Tx MXene. Absorbed Water enhances the microscopic mobility of confined [EMIm+][Tf2N–], even though the ionic liquid itself is not very hygroscopic. The Absorbed Water molecules predominantly reside on the termination groups of the more hydrophilic MXene layers, thereby displacing the ions from the surface and facilitating their motions in the MXene matrix.
Peter A. Dowben - One of the best experts on this subject based on the ideXlab platform.
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Polyvinylidene fluoride–trifluoroethylene as a reservoir for Absorbed Water
Materials Letters, 2007Co-Authors: Peter Jacobson, Stephen Ducharme, Luis G. Rosa, Kristin L. Kraemer, Peter A. DowbenAbstract:Abstract The absorption of Water in Langmuir–Blodgett films of ferroelectric copolymers of polyvinylidene fluoride with trifluoroethylene is shown to depend upon the film thickness. This Water absorption can have a profound effect on the dielectric properties of the copolymer films.
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Water absorption and desorption from the dipole ordered polymer poly(methylvinylidene cyanide)
The journal of physical chemistry. B, 2006Co-Authors: Peter Jacobson, Carolina C. Ilie, I. N. Yakovkin, Matt Poulsen, D. Sahadeva Reddy, James M. Takacs, Peter A. DowbenAbstract:From thermal desorption studies, we find evidence that Absorbed Water in the bulk of poly(methylvinylidene cyanide) is more weakly bound than is the case for copolymer films of poly(vinylidenefluoride-trifluoroethylene). Ultraviolet laser enhanced thermal desorption of Absorbed Water exhibits little light polarization dependence for poly(methylvinylidene cyanide) in contrast to Absorbed Water in copolymer films of poly(vinylidenefluoride-trifluoroethylene). The implications of these differences are discussed.
Naresh C Osti - One of the best experts on this subject based on the ideXlab platform.
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humidity exposure enhances microscopic mobility in a room temperature ionic liquid in mxene
Journal of Physical Chemistry C, 2018Co-Authors: Naresh C Osti, Matthew Thompson, Katherine L Van Aken, Mohamed Alhabeb, Madhusudan Tyagi, Jongkahk Keum, Peter T Cummings, Yury Gogotsi, Eugene MamontovAbstract:Present and future electrochemical devices employing advanced electrode and electrolyte materials are expected to operate in diverse environments, where they are exposed to variable conditions, such as changing humidity levels. Such conditions can possibly alter the microscopic mechanisms that influence the electrochemical performance. Here, using quasi-elastic neutron scattering and molecular dynamics simulations, we investigate the influence of humidity exposure on a room-temperature ionic liquid, [EMIm+][Tf2N–], in Ti3C2Tx MXene. Absorbed Water enhances the microscopic mobility of confined [EMIm+][Tf2N–], even though the ionic liquid itself is not very hygroscopic. The Absorbed Water molecules predominantly reside on the termination groups of the more hydrophilic MXene layers, thereby displacing the ions from the surface and facilitating their motions in the MXene matrix.
George Zografi - One of the best experts on this subject based on the ideXlab platform.
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The Effects of Absorbed Water on the Properties of Amorphous Mixtures Containing Sucrose
Pharmaceutical research, 1999Co-Authors: Sheri L. Shamblin, George ZografiAbstract:Purpose. To measure the Water vapor absorption behavior of sucrose-poly(vinyl pyrrolidone) (PVP) and sucrose-poly(vinyl pyrrolidone co-vinyl acetate) (PVP/VA) mixtures, prepared as amorphous solid solutions and as physical mixtures, and the effect of Absorbed Water on the amorphous properties, i.e., crystallization and glass transition temperature, Tg, of these systems.
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Molecular Mobility in Mixtures of Absorbed Water and Solid Poly(vinylpyrrolidone)
Pharmaceutical Research, 1993Co-Authors: Cynthia A. Oksanen, George ZografiAbstract:Poly(vinylpyrrolidone) (PVP) was used as model system to examine molecular mobility in mixtures of Absorbed Water with solid amorphous polymers. Water vapor absorption isotherms were determined, along with diffusion and proton NMR relaxation measurements of Absorbed Water. Concurrently, measurements of glass transition temperatures ( T _g) and carbon-13 NMR relaxation times for PVP were determined as a function of Water content. Two Water contents were used as reference points: W _m, obtained from the fit of Water absorption isotherms to the BET equation, corresponding to the first shoulder in the sigmoid isotherm; and W _g, the amount of Water necessary to depress T _g to the isotherm temperature. Translational diffusion coefficients of Water, along with proton T _1 relaxation time constants, show that both the translational and the rotational mobility of the Water is hindered by the presence of the solid polymer and that the Absorbed Water is most likely represented by two or more populations of Water with different modes or time scales of motion. The presence of "tightly bound” or immobilized Water at levels corresponding to W _m, however, is unlikely, since Water molecules maintain a high degree of mobility, even at the lowest levels of Water. Above W _g, Water shows an increase in mobility with increasing Water content, but it is always less mobile than bulk Water. With increasing Water content, carbon-13 T _1 relaxation time constants for PVP, measured under the same conditions as above, indicate a major increase in the molecular mobility of carbon atoms associated with the pyrrolidone side chains.
