POS4-0034
Tuning the mechanics of capillary suspension gels via particle bidispersity
Topic
S4. Colloids, Interfaces, and Molecular Assemblies for Functional Soft Materials
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Ahmed Jarray (Multi Scale Mechanics (MSM), MESA+ Institute for Nanotechnology, University of Twente, 7500AE Enschede, The Netherlands)
Co-Author(s)
Abstract
Capillary suspensions are particulate systems where networks of liquid bridges between solid particles in two immiscible liquids generate gels. Using bidisperse particles broadens the accessible microstructures, but the combined effects of particle size ratio and composition remain unclear.
Here we systematically study bidisperse capillary suspensions across size ratios and large-particle fractions. Rheology and confocal microscopy reveal six network architectures and identify critical amounts of large particles that preserve gel integrity at strong size disparity. We condense these results into a microstructure–property phase diagram that guides tuning of structure and rheology. Coupled DEM–CFD simulations reproduce the experiments and show how, at high size disparity and large-particle content, small particles fill interstitial gaps, form additional capillary bridges, and reinforce the network, whereas at low large-particle fractions the network is disrupted and gels soften.
Here we systematically study bidisperse capillary suspensions across size ratios and large-particle fractions. Rheology and confocal microscopy reveal six network architectures and identify critical amounts of large particles that preserve gel integrity at strong size disparity. We condense these results into a microstructure–property phase diagram that guides tuning of structure and rheology. Coupled DEM–CFD simulations reproduce the experiments and show how, at high size disparity and large-particle content, small particles fill interstitial gaps, form additional capillary bridges, and reinforce the network, whereas at low large-particle fractions the network is disrupted and gels soften.
