InterPore2026

Gas-diffusion-dominated foam coarsening in non-Newtonian fluids

19 May 2026, 15:05

1h 30m

Poster Presentation (MS05) Physics of multiphase flow in diverse porous media Poster

Speaker

Tongke Zhou (Department of chemical engineering, University of Manchester)

Description

Foams stabilised by additives are increasingly employed in subsurface applications, including geological carbon sequestration and enhanced oil recovery, to improve gas flow control in porous media. The stability of foam is governed by multiple coupled processes, including liquid drainage, bubble coarsening and coalescence, which are strongly influenced by fluid rheology. Non-Newtonian fluids introduce complexity by changing lamellae stability, gas transport, and foam topology. Despite extensive studies on foam stability, the mechanisms controlling foam coarsening in non-Newtonian fluids remain insufficiently understood.

In this work, a microscale study was conducted to investigate gas-diffusion-dominated foam coarsening in non-Newtonian fluids under confinement. A Hele–Shaw cell with a controlled gap height was designed to mimic fracture-like geometries. Cellulose nanofibrils (CNF) were used to formulate non-Newtonian fluids with tuneable rheological properties for foam generation. Rheological measurements were combined with optical imaging to quantify the evolution of bubble size distributions and lamellae curvature, as well as their relationship with bulk rheology. The results demonstrate a nonlinear enhancement of foam stability with increasing CNF concentration, accompanied by suppressed bubble coarsening and reduced lamellae mobility. Quantitative analysis based on reconstructed bubble geometries reveals that CNF-stabilised lamellae significantly hinder gas diffusion and bubble rearrangement, promoting the emergence of quasi-equilibrium foam structures. These findings provide mechanistic insight into the interplay between non-Newtonian rheology and gas transport in confined space, with implications for the design of foam systems for subsurface applications.