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Measuring Material Microstructure Under Flow Using 1-2 Plane Flow-Small Angle Neutron Scattering
Published on: February 6, 2014
Measuring small compartments with relatively weak gradients by angular double-pulsed-field-gradient NMR.
Darya Morozov1, Leah Bar, Nir Sochen
1School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel.
Magnetic Resonance Imaging
|October 30, 2012
Summary
Nuclear Magnetic Resonance (NMR) diffusion-diffraction patterns help determine compartment sizes. Bipolar angular double-pulsed-field gradient (d-PFG) NMR effectively measures small microcapillary sizes despite background gradients.
Area of Science:
- Physics
- Chemistry
- Materials Science
Background:
- NMR diffusion-diffraction patterns offer insights into restricted diffusion and compartment sizes.
- Extracting compartment sizes typically requires high wave-vector (q) values, necessitating strong gradient systems.
- Angular double-pulsed-field gradient (d-PFG) NMR was proposed to measure compartment sizes at lower q-values.
Purpose of the Study:
- To characterize microcapillary sizes using single-PFG (s-PFG) and angular d-PFG NMR.
- To investigate the impact of background gradients on angular d-PFG NMR experiments.
- To evaluate the effectiveness of bipolar angular d-PFG NMR in overcoming background gradient interference.
Main Methods:
- Utilized single-PFG (s-PFG) NMR and angular d-PFG NMR.
- Investigated microcapillaries with an approximate diameter of 2±1μm.
- Employed bipolar angular d-PFG NMR to mitigate background gradient effects.
Main Results:
- Observed strong background gradients in microcapillaries, masking microscopic anisotropy (μA).
- Angular d-PFG NMR yielded unexpected signal intensity (E(φ)) profiles due to background gradients.
- Bipolar angular d-PFG NMR successfully suppressed background gradients, revealing expected E(φ) profiles.
Conclusions:
- Bipolar angular d-PFG NMR enables accurate compartment dimension determination even with weak gradient pulses.
- This methodology provides a rapid, reliable, and non-invasive approach for estimating small pore sizes.
- The technique is effective in the presence of significant magnetic susceptibility variations.
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