Accelerating Restricted Diffusion NMR Studies with Time-Resolved and Ultrafast Methods.

Area of Science:

• Physics
• Materials Science
• Chemistry

Background:

• Pulsed field gradient nuclear magnetic resonance (PFG-NMR) offers non-invasive study of fluid diffusion in porous materials.
• Traditional PFG-NMR measurements for restricted diffusion are time-consuming due to numerous repetitions.
• Detailed information on pore size and tortuosity can be obtained by analyzing diffusion delays.

Purpose of the Study:

• To accelerate restricted diffusion measurements using PFG-NMR.
• To introduce and compare two novel acceleration strategies: time-resolved diffusion NMR and ultrafast Laplace NMR.
• To demonstrate the feasibility of these accelerated techniques on a relevant biological material.

Main Methods:

• Time-resolved diffusion NMR utilizing time-resolved non-uniform sampling.
• Ultrafast Laplace NMR employing spatial encoding of 2D data.
• Experimental validation using water diffusion in thermally modified pine tracheid cells.

Main Results:

• Both time-resolved diffusion NMR and ultrafast Laplace NMR achieve 1-2 orders of magnitude acceleration in acquisition time.
• The study details the distinct advantages and limitations of each accelerated technique.
• Successful application of the methods to investigate water diffusion within tracheid cells of modified pine wood.

Conclusions:

• Accelerated PFG-NMR techniques significantly reduce measurement time for studying restricted diffusion.
• Time-resolved diffusion NMR and ultrafast Laplace NMR provide viable alternatives for efficient porous material analysis.
• These methods enhance the practical application of NMR for characterizing complex porous structures like wood.