NMR characterization of general compartment size distributions

Area of Science:

• Physics
• Materials Science
• Biophysics

Background:

• Molecular diffusion impacts Nuclear Magnetic Resonance (NMR) signals in complex materials.
• Estimating compartment size distributions is crucial for understanding material properties.

Purpose of the Study:

• To establish theoretical relationships between NMR signal intensity and pore size distribution moments.
• To develop a numerical method for estimating compartment size distribution moments.
• To demonstrate the technique's ability to differentiate based on mean and variance.

Main Methods:

• Derivation of theoretical relationships for planar, cylindrical, and spherical pores.
• Development of a numerical method using orthogonal basis functions for signal analysis.
• Application to simulated and real data from water-filled microcapillaries.

Main Results:

• Successfully estimated compartment size distribution moments from NMR signals.
• Demonstrated contrast generation based on both mean and variance of compartment sizes.
• Validated the approach using controlled microcapillary experiments.

Conclusions:

• The described NMR technique effectively characterizes compartment size distributions.
• This method provides insights into material heterogeneity beyond simple averages.
• Applications include analyzing emulsions and nerve fascicle axon diameters.