Journal article

Water Diffusion in Complex Systems Measured by PGSE NMR Using Chemical Shift Selective Stimulated Echo: Elimination of Magnetization Exchange Effects

Thomas G Meikle, David W Keizer, Frances Separovic, Shenggen Yao

The Journal of Chemical Physics | AIP Publishing | Published : 2021

Abstract

The interpretation of molecular translational diffusion as measured by pulsed gradient spin-echo NMR (PGSE NMR) can be complicated by the presence of chemical exchange and/or dipolar cross-relaxation (including relayed cross-relaxation via spin diffusion). The magnitude of influence depends on the kinetics of exchange and/or dipolar cross-relaxation present within the system as well as the PGSE NMR sequences chosen for the measurements. Firstly, we present an exchange induced zero-crossing phenomenon for signal attenuation of water in lipidic cubic phases (LCPs, formed by a mixture of monoolein and water) in the presence of pulsed gradients observed using a standard STimulated Echo (STE) seq..

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