Molecular and Ionic Diffusion in Ion Exchange Membranes and Biological Systems (Cells and Proteins) Studied by NMR

Abstract

The results of NMR, and especially pulsed field gradient NMR (PFG NMR) investigations, are summarized. Pulsed field gradient NMR technique makes it possible to investigate directly the partial self-diffusion processes in spatial scales from tenth micron to millimeters. Modern NMR spectrometer diffusive units enable to measure self-diffusion coefficients from 10−13 m2/sec to 10−8 m2/sec in different materials on 1 H, 2 H, 7 Li, 13 C, 19 F, 23 Na, 31 P, 133 Cs nuclei. PFG NMR became the method of choice for reveals of transport mechanism in polymeric electrolytes for lithium batteries and fuel cells. Second wide field of application this technique is the exchange processes and lateral diffusion in biological cells as well as molecular association of proteins. In this case a permeability, cell size, and associate lifetime could be estimated. The authors have presented the review of their research carried out in Karpov Institute of Physical Chemistry, Moscow, Russia; Institute of Problems of Chemical Physics RAS, Chernogolovka, Russia; Kazan Federal University, Kazan, Russia; Korea University, Seoul, South Korea; Yokohama National University, Yokohama, Japan. The results of water molecule and Li+, Na+, Cs+ cation self-diffusion in Nafion membranes and membranes based on sulfonated polystyrene, water (and water soluble) fullerene derivative permeability in RBC, casein molecule association have being discussed.

Polymer Electrolytes for Lithium-Ion Batteries Studied by NMR Techniques

“…The results of the NMR study of gel electrolytes are given in [39,40,47,49,50,53,54,56,57,80,119,122,[124][125][126]130].…”

“…where А is the echo signal intensity at the magnetic field gradient pulse with the amplitude g, А0 is the echo signal intensity without gradient pulse, δ is the duration of the magnetic field gradient pulse, Δ is the interval between the gradient pulses, γ is the nuclear gyromagnetic ratio, and Ds is the self-diffusion coefficient. The 7 Li diffusion decay is approximated by Equation (1) [126], Figure 10.…”

“…As shown in Figure 10, the translational motion of Li + cations is characterized by the self-diffusion coefficient only regardless of the EC content. The diffusion decay shape of 1 H is more complicated (Figure 11) and can be decomposed into three exponential components described by Equation ( 2) [126]. The self-diffusion coefficient of H atoms can also be characterized by the average coefficient.…”

“…[ Local ionic and molecular motion correlation times can be calculated from spinrelaxation of the 7 Li and 1 H temperature dependences [126]. The temperature dependences of the 7 The temperature dependences of the correlation times are shown in Figure 16.…”

NMR spectroscopy of lipidic cubic phases

“…More recently, NMR has flourished with a library of pulse sequences enabling selective, high sensitivity experiments to be performed. As reviewed by Volkov et al and Price (2009;Volkov et al 2021), the recent advances in pulse sequences and hardware technology have enabled discriminating self-diffusion processes on spatial scales from μm to mm and diffusion rates from 10 −13 to 10 −8 m 2 s −1 . Exchange processes and lateral diffusion in biological cells as well as molecular association of proteins and lipids are now routinely derived from NMR studies, providing insights into cellular permeability and structures (Waldeck et al 1997).…”