Diffusion studies in porous media with the "inside-out" technique

Area of Science:

• Materials Science
• Physical Chemistry
• Chemical Engineering

Background:

• Understanding fluid transport in porous media is crucial for various industrial applications.
• Porous materials like glass beads are common in filtration, catalysis, and geological formations.
• Accurate measurement of diffusion is essential for predicting fluid behavior in these systems.

Purpose of the Study:

• To investigate water diffusion dynamics within a glass beads porous medium.
• To analyze a new method for determining the mean square displacement of hydrogen molecules.
• To differentiate diffusion characteristics between pure water and water-in-porous-media systems.

Main Methods:

• Utilized the "One-Sided Access" sensor for diffusion measurements.
• Employed a three-pulse sequence with a static field gradient to measure stimulated echo to primary echo ratios.
• Analyzed the long-time mean square displacement of hydrogen molecules.

Main Results:

• Successfully measured water diffusion in a glass beads porous medium.
• The developed approach allowed for the analysis of molecular displacement.
• A discernible difference in the apparent diffusion coefficient was observed between pure water and water/glass beads mixtures.

Conclusions:

• The "One-Sided Access" sensor is effective for diffusion studies in porous media.
• The analyzed method provides insights into molecular diffusion behavior.
• Porous structures significantly alter water diffusion coefficients compared to bulk water.