Kittler W C, Obruchkov S, Galvosas P, Hunter M W
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, 6140 Wellington, New Zealand.
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, 6140 Wellington, New Zealand; Magritek Ltd., 32 Salamanca Rd., 6012 Wellington, New Zealand.
J Magn Reson. 2014 Oct;247:42-49. doi: 10.1016/j.jmr.2014.08.005. Epub 2014 Aug 30.
Pulsed field gradient nuclear magnetic resonance provides a powerful tool for the measurement of particle diffusion and mobility. When these particles are contained in a porous medium, the diffusive process is influenced by the pore boundaries, and their effect on diffusion measurements provides information about the pore space. The acquisition of the apparent diffusion coefficient and its dependence on time, in the short time limit, reveals the surface to volume ratio of the porous medium, and in the long time limit, its tortuosity. With conventional pulsed field gradient techniques, processes where pore boundaries are evolving on the sub-second time scale cannot be resolved. Using pulsed second order magnetic fields in conjunction with one-dimensional imaging and the pulse sequence Difftrain, this paper presents a proof of concept for the first ever real time single-shot surface to volume NMR measurement.
脉冲场梯度核磁共振为测量粒子扩散和迁移率提供了一个强大的工具。当这些粒子包含在多孔介质中时，扩散过程会受到孔隙边界的影响，而它们对扩散测量的影响提供了有关孔隙空间的信息。在短时间极限内获取表观扩散系数及其对时间的依赖性，可揭示多孔介质的表面积与体积之比，而在长时间极限内，则可揭示其曲折度。使用传统的脉冲场梯度技术，无法分辨孔隙边界在亚秒时间尺度上演变的过程。本文结合一维成像和脉冲序列Difftrain使用脉冲二阶磁场，首次提出了实时单次表面积与体积核磁共振测量的概念验证。
