Modeling liquid porosimetry in modeled and imaged 3-D fibrous microstructures

Area of Science:

• Materials Science
• Fluid Dynamics
• Porous Media Physics

Background:

• Understanding pore size distribution is crucial for characterizing fibrous materials.
• Fibrous materials exhibit complex pore structures influencing fluid transport.
• Distinguishing geometric from fluid-intrusion-based pore sizes is challenging.

Purpose of the Study:

• To develop a method for distinguishing geometric and porosimetric pore size distributions in fibrous materials.
• To model fluid intrusion in 3D fibrous microstructures.
• To investigate the impact of material properties on pore connectivity.

Main Methods:

• Simulating nonwetting fluid intrusion in 3D reconstructed and virtual fibrous microstructures.
• Applying a Poisson line network model to derive theoretical geometric pore size distributions.
• Analyzing pore space connectivity using accessible and allowed pore volume graphs (access function graphs).

Main Results:

• Geometric pore size distributions in hydroentangled nonwovens are approximated by a two-parametric Gamma distribution.
• The ink-bottle effect significantly impacts fluid intrusion.
• Pore connectivity in homogeneous fibrous media depends on thickness, solid volume fraction (SVF), and fiber diameter.
• Increasing thickness or SVF decreases connectivity; increasing fiber diameter enhances it.
• Access function graphs can identify bottleneck pores in layered materials.

Conclusions:

• The study provides a framework for analyzing pore structure in fibrous materials.
• Material properties critically influence fluid transport and pore connectivity.
• The developed models and methods aid in predicting material behavior under fluid intrusion.