Six-dimensional spin density/velocity NMR microscopy of percolation clusters

Area of Science:

• Physics
• Materials Science
• Chemical Engineering

Background:

• Percolation theory describes the formation and properties of clusters in random systems.
• Understanding fluid flow in porous media is crucial for various scientific and engineering applications.
• Characterizing the complex geometry of pore spaces is essential for predicting transport phenomena.

Purpose of the Study:

• To fabricate three-dimensional (3D) percolation cluster objects using computer-simulated templates.
• To experimentally investigate water percolation through these 3D structures using advanced imaging techniques.
• To establish a method for reliably quantifying characteristic parameters of the pore space and flow.

Main Methods:

• Fabrication of 3D percolation cluster objects based on computer simulations.
• Experimental investigation using nuclear magnetic resonance (NMR) microimaging.
• Application of a six-dimensional spin density/velocity NMR imaging pulse sequence for simultaneous mapping of structure and flow.

Main Results:

• Successfully created 3D percolation cluster objects.
• Obtained combined 3D spin-density distribution and 3D velocity vector fields of water.
• Developed an evaluation procedure to reliably determine fractal dimensionality, backbone fractal dimensionality, and correlation length.

Conclusions:

• The study demonstrates a novel approach to fabricating and characterizing 3D porous media.
• NMR microimaging is a powerful tool for visualizing and quantifying fluid dynamics in complex pore structures.
• The established evaluation procedure accurately provides key parameters for understanding transport in disordered systems.