Physical characterization using diffusion NMR spectroscopy

Zubkov, Mikhail; Dennis, Gary R.; Stait‐Gardner, Timothy; Torres, Allan M.; Willis, Scott A.; Zheng, Gang; Price, William S.

doi:10.1002/mrc.4530

Cited by 18 publications

(13 citation statements)

References 88 publications

(132 reference statements)

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“…NMR diffusion experiments are based on the measurement of the signal decay after applying a train of field gradient pulses (PFG) of duration δ and increasing intensity g along the z direction. The signal decay intensity I ( q , t d ) measured at a fixed time t d can be related to the mean-squared displacement (MSD), ⟨ z 2 ⟩, as follows where q = (δγ g )/2π and γ is the magnetogyric ratio of the observed nucleus.…”

Section: Resultsmentioning

confidence: 99%

Xenon Dynamics in Ionic Liquids: A Combined NMR and MD Simulation Study

et al. 2020

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The translational dynamics of xenon gas dissolved in room-temperature ionic liquids (RTILs) is revealed by 129 Xe NMR and molecular dynamics (MD) simulations. The dynamic behavior of xenon gas loaded in 1-alkyl-3-methylimidazolium chloride, [C n C 1 im]Cl ( n = 6, 8, 10), and hexafluorophosphate, [C n C 1 im][PF 6 ] ( n = 4, 6, 8, 10) has been determined by measuring the 129 Xe diffusion coefficients and NMR relaxation times. The analysis of the experimental NMR data demonstrates that, in these representative classes of ionic liquids, xenon motion is influenced by the length of the cation alkyl chain and anion type. 129 Xe spin–lattice relaxation times are well described with a monoexponential function, indicating that xenon gas in ILs effectively experiences a single average environment. These experimental results can be rationalized based on the analysis of classical MD trajectories. The mechanism described here can be particularly useful in understanding the separation and adsorption properties of RTILs.

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Section: Resultsmentioning

confidence: 99%

Xenon Dynamics in Ionic Liquids: A Combined NMR and MD Simulation Study

et al. 2020

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“…Once the hydrogel was selected, we studied the diffusion into the system of a model drug (ibuprofen (IB), an anti-inflammatory drug often employed as model in drug release studies [4,29,44]), used both as pure molecule and as 1:1 complex with β-Cyclodextrins (β-CD) to slow down the drug path. These measures were conducted by diffusion-nuclear magnetic resonance (NMR) spectroscopy methods [45] combined with a high-resolution magic angle spinning (HR-MAS) setup to obtain high resolution data. Several applications of this novel technique to the investigation of soft materials [46,47], heterogeneous systems [48] and intact tissues [49] are reported in literature.…”

Section: Introductionmentioning

confidence: 99%

TEMPO-Nanocellulose/Ca2+ Hydrogels: Ibuprofen Drug Diffusion and In Vitro Cytocompatibility

et al. 2020

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Stable hydrogels with tunable rheological properties were prepared by adding Ca2+ ions to aqueous dispersions of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-oxidized and ultra-sonicated cellulose nanofibers (TOUS-CNFs). The gelation occurred by interaction among polyvalent cations and the carboxylic units introduced on TOUS-CNFs during the oxidation process. Both dynamic viscosity values and pseudoplastic rheological behaviour increased by increasing the Ca2+ concentration, confirming the cross-linking action of the bivalent cation. The hydrogels were proved to be suitable controlled release systems by measuring the diffusion coefficient of a drug model (ibuprofen, IB) by high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy. IB was used both as free molecule and as a 1:1 pre-formed complex with β-cyclodextrin (IB/β-CD), showing in this latter case a lower diffusion coefficient. Finally, the cytocompatibility of the TOUS-CNFs/Ca2+ hydrogels was demonstrated in vitro by indirect and direct tests conducted on a L929 murine fibroblast cell line, achieving a percentage number of viable cells after 7 days higher than 70%.

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“…The restricted diffusion is characterized by the anomalous oscillating feature of NMR echo attenuation in diffusion measurement in contrast to the free diffusion manner that decays linearly in the log-plot of echo intensity against δ 2 Δ of Equation (1) [ 44 , 45 , 46 ]. Free diffusion is a phenomenon wherein the species in a gas or liquid undergo random walks while colliding with surrounding species according to thermal motion [ 47 ].…”

Section: Evaluation and Discussion Of Practical Materialsmentioning

confidence: 99%

Ion Transport in Solid Medium—Evaluation of Ionic Mobility for Design of Ion Transport Pathways in Separator and Gel Electrolyte

Saito

2021

Membranes

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Further improvement in the performance of lithium secondary batteries will be an indispensable issue to realize a decarbonized society. Among them, the batteries for electric vehicles still have many issues to be addressed because they are subject to various conditions such as high-power performance, safety, and cost restrictions for widespread use. Those subjects require extensive researches from the improvement of each element material to control the battery system to optimize the total performance. Based on this idea, we have been conducting research focusing on ion movement to elucidate the ion conduction mechanism from the microscopic point of view. It has been recognized that the ionic mobility in the battery, which dominates the power performance of the battery, is affected by the solid environment in which the ions move (separator and electrode materials) and the evaluation of ion movement, including the interaction with the surroundings, is necessary as an essential step for battery design. In this article, I will introduce the evaluation approach of ion dynamics and the evaluation results of mobility and interactive situations of carrier ions in the practical separator membranes and gel electrolytes. Finally, the direction of material design is outlined through this review.

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Physical characterization using diffusion NMR spectroscopy

Cited by 18 publications

References 88 publications

Xenon Dynamics in Ionic Liquids: A Combined NMR and MD Simulation Study

Xenon Dynamics in Ionic Liquids: A Combined NMR and MD Simulation Study

TEMPO-Nanocellulose/Ca2+ Hydrogels: Ibuprofen Drug Diffusion and In Vitro Cytocompatibility

Ion Transport in Solid Medium—Evaluation of Ionic Mobility for Design of Ion Transport Pathways in Separator and Gel Electrolyte

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