David Halat – @davidhalat
We report 1H, 19F, and 7Li electrophoretic NMR (eNMR) measurements, which directly quantify ion and solvent motion under an electric field, to reveal solvent motion driven by cation–solvent coordination in Li-ion battery electrolytes. We further corroborate molecular dynamics solvation motifs by rationalizing concentration-dependent 1H NMR shifts through DFT calculations.
Sarah Anderson – @sanderson9135
The initial goal of this research was to reproduce a NMR study by Delso et al. which evidenced the existence of a hydrogen bonding network. Each solvent contained choline-chloride, a hydrogen bond acceptor, and water. Previous studies provided a qualitative analysis, evidenced by the Nuclear Overhauser Effect. Through the analysis of nOe peak intensities with varied mixing time one may understand this network quantitatively.
Chuanyu Yan – @yan_chuanyu
The liquid-solid interface is of great importance in fundamental and applied research. However, the in-situ characterization of liquid-solid interfaces is very challenging. In this work, we demonstrated that {1H–29Si-}1H multiple-contact cross polarization with indirect detection (MCPi) solid-state nuclear magnetic resonance (ssNMR) spectroscopy is an excellent tool for studying dehydration and deuterium exchange at the solvent-silica interface.
Yady Senayda Garcia Castillo – @yadygarcia89
Composites between OIPCs and polymer particles have recently been of interest because they combine the non-flammability, non-volatility, plasticity, electrochemical, and thermal stability of OIPCs, while at the same offering the mechanical stability provided by the polymer. ssNMR is implemented to study the structural changes and ions dynamics and is correlated with Electrochemical Impedance Spectroscopy (EIS) to determine the ion transport in the composite. It is expected that the composite will take advantage of the intrinsic properties of the OIPC like plasticity, the mechanical strength of the polymer, and the formation of the interphase between them, which will add new properties.
Thomas Webber – @ThomasW35463255
Overhauser Dynamic Nuclear Polarization (ODNP) is a novel magnetic resonance tool which combines NMR and EPR to study local (within 1 nm) water dynamics near spin-labeled surfaces. I apply ODNP to study water diffusion in aqueous polymer systems, showing that polymer crowding slows molecular water significantly.
Riley W. Hooper – @rileyhooper97
Halogen NMR and NQR spectroscopy is often challenging due to large quadrupole moments for the NMR-active nuclei of Cl, Br, and I. Nevertheless, these nuclei can provide invaluable structural and dynamic information for materials. We have studied two such examples of lead-bromide materials via 79/81Br NMR and NQR spectroscopy.
Racha Bayzou – @RBayzou
Amorphous LiPON thin-films are the standard electrolytes for all-solid microbatteries. They are prepared by the radiofrequency sputtering from Li3PO4 targets under a pure N2 atmosphere. In this work, we elucidate the relationships between deposition conditions and local atomic-level structure using 31P, 7Li and 14N solid-state NMR.
Ran Eitan Abutbul – @RanEitanAbutbul
This work demonstrates the endogenous DNP approach in nanoparticles where the polarizing agents are transition metal ions with unpaired electrons incorporated in the inorganic lattice. CdS:Mn nanoparticles were synthesized and characterized using TEM, EPR, and ICP-MS. Significant DNP enhancement for 113Cd nuclei surface and core moieties was observed.
Hongtao Qu – @QuHongtao
We investigate the impact of Al incorporation on the structure and dynamics of Al-doped lithium thiophosphates (Li3-3xAlxPS4) based on β-Li3PS4. 27Al and 6Li MAS NMR spectra confirm that Al3+ ions occupy octahedral sites in the structure. Quantitative analyses of 27Al NMR that the maximum Al incorporation is x=0.06 in Li3-3xAlxPS4. NMR relaxometry shows that the activation barrier for long-range Li ion diffusion in β-Li3PS4 hardly changes upon Al incorporation, but the onset temperature for doping comes down significantly. The activation barrier in the subsequently formed multiphase material decreases significantly, however, indicating a different more efficient Li ion conduction pathways.
Mariana Coelho Santoro – @marianacsantoro
This work describes a solid-state 31P NMR investigation of the chemical nature of adsorbed phosphate groups in Ca/Mg modified biochars. Biomass was used to synthesise steam-activated biochars, followed by precipitation of Ca or Mg metals for later adsorption of phosphates from phosphate-rich solutions, aiming the obtention of a material with bioavailable phosphate forms to be used as slow-release fertilisers. The 31P NMR results showed that the Mg/modified biochars had a higher phosphate adsorption capacity. Also, signals with distinct chemical shifts and linewidths were observed in the spectra of samples immersed in different phosphate solutions.
Leave a Reply