Unraveling the relationship between dense suspension flow and particle and solvent identity

Dense suspensions can show a range of rheological properties such as non-Newtonian flow behaviors (i.e. shear thinning and shear thickening) and flow hysteresis. Recent studies have explored how their non-Newtonian flow behaviors can be manipulated by changing the suspending solvent[1], particle surface chemistry[2], and particle size[3], but a parametric study of all three factors has yet to be performed. Here, we measure the steady state rheology of silica particles as a function of solvent molecular weight (MW), surface chemical functionalities, and particle size. Our findings show that the rheological properties of dense suspensions can be tuned by seemingly small changes in solvent or particle chemistry and particle size. These results allow us to explore how solvation, frictional, and Brownian forces compete during dense suspension flow.


[1] S. R. Raghavan, et al., “Rheology of Silica Dispersions in Organic Liquids: New Evidence For Solvation Forces Dictated by Hydrogen Bonding”, Langmuir 7920–7930 (2000)
[2] N. James, et al. “Interparticle hydrogen bonding can elicit shear jamming in dense suspensions”, Nature Materials 965–970 (2018)
[3] B.M Guy, et al., “Towards a Unified Description of the Rheology of Hard-Particle Suspensions”, Physical Review Letters 088304 (2015)