Burcaw Lauren M, Callaghan Paul T
MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, New Zealand.
J Magn Reson. 2009 Jun;198(2):167-73. doi: 10.1016/j.jmr.2009.02.009. Epub 2009 Mar 6.
We present a new method for observing fluid diffusion in a porous medium. The method employs 2D exchange spectroscopy for molecules diffusing in the presence of local magnetic field inhomogeneities, in our case distilled water in various sized glass bead packs. Our experiment involves an acquisition and evolution time domain with the two Fourier domains corresponding to the spectral distribution of local fields. We show that exchange in the internal magnetic field can be seen in a 2D spectrum with a characteristic time on the order of that required to diffuse 0.15 sphere diameters with similar behavior found for computer simulations. The method is potentially useful for studying the internal migrations in more complicated systems such as sandstones or other porous media.
我们提出了一种观察多孔介质中流体扩散的新方法。该方法采用二维交换光谱法来研究在局部磁场不均匀情况下分子的扩散，在我们的实验中是研究不同尺寸玻璃珠包中的蒸馏水。我们的实验涉及一个采集和演化时域，其两个傅里叶域对应于局部场的光谱分布。我们表明，内部磁场中的交换可以在二维光谱中看到，其特征时间约为扩散0.15个球体直径所需的时间，计算机模拟也发现了类似的行为。该方法对于研究砂岩或其他多孔介质等更复杂系统中的内部迁移可能是有用的。
