Recent advances in NMR diffusometry for porous media research

Wilfred Kittler1, Huabing Liu1, Fangrong Zong1, Stefan Andreas Hertel1, Marcel Nogueira d'Eurydice1,2, Xindi Wang3, Peter Hosking3, M. Cather Simpson3, Tristan Anselm Kuder4, Frederik Laun4, Mark Hunter1,5, Sergei Obruchkov1 and Petrik Galvosas1
1MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140, New Zealand 2School of Petroleum Engineering, The University of New South Wales, Sydney, NSW 2052, Australia 3The Photon Factory and the School of Chemical Sciences, The University of Auckland, Auckland, New Zealand 4Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69121 Heidelberg, Germany 5Magritek Limited, 32 Salamanca Road, Wellington 6012, New Zealand
June 15, 2015

Accounting for the influence of molecular motion in NMR experiments is nearly as old as the discovery of NMR itself [1]. However, with the introduction of pulsed magnetic field gradients [2] NMR became a highly versatile tool for studying diffusion and flow in many areas such as physics, chemistry, material science, medical research and clinical routine.
This lecture will revolve around new options offered by NMR diffusometry in the context of porous media research. We will report on the use of second order magnetic fields which allow for the parallel acquisition of q-space [3], thus en- abling real time monitoring of averaged propagators [4] and single-shot surface- to-volume ratio measurements in porous media [5]. We will also discuss new imaging approaches for porous materials which consist of disconnected pores. While this method is still based on the work horse of NMR diffusometry as introduced exactly 50 years ago [2] deliberate extension of one gradient pulse [6] allows for Magnetic Resonance Pore Imaging (MRPI) at resolutions well beyond the limits of conventional MRI [7].

As time permits the lecture will touch on approaches for extracting frac- tional anisotropy based on Diffusive Diffusion Correlation SpectroscopY (DD- COSY) [8], the determination of pore length scales and surface relaxivities at low magnetic fields using 1D and 2D approaches [9] and the study of higher or- der terms as occurring in the expression for the short time behaviour of diffusion coefficients in porous media [10].

References
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[3] Kittler, W. C., Galvosas, P., and Hunter, M. W. J. Magn. Reson. 244, 46-52, (2014).
[4] Kittler, W., Hunter, M., and Galvosas, P. Phys. Rev. E, minor revision (2015).
[5] Kittler, W. C., Obruchkov, S., Galvosas, P., and Hunter, M. W. J. Magn. Reson. 247, 42-49, (2014).
[6] Laun, F. B., Kuder, T. A., Semmler, W., and Stieltjes, B. Phys. Rev. Lett. 107, 048102, (2011).
[7] Hertel, S. A., Wang, X., Hosking, P., Simpson, M. C., Hunter, M., and Galvosas, P. Phys. Rev. E, accepted (2015).
[8] Callaghan, P. T. and Furo, I. J. Chem. Phys. 120(8), 4032-4038 (2004). [9] Liu, H., Nogueira d'Eurydice, M., Obruchkov, S., and Galvosas, P. J.
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[10] Mitra, P. P., Sen, P. N., and Schwartz, L. M. Phys. Rev. B 47, 8565-8574 (1993).