arXiv subjects

C. Anzivino

Publications and source records attributed to C. Anzivino.

2 recordsLinked to original sources

arXiv2024

Shear flow of non-Brownian rod-sphere mixtures near jamming

We use the discrete element method, taking particle contact and hydrodynamic lubrication into account, to unveil the shear rheology of suspensions of frictionless non-Brownian rods in the dense packing fraction regime. We find that, analogously to the random close packing volume fraction, the shear-driven jamming point of this system varies in a non-monotonic fashion as a function of the rod aspect ratio. The latter strongly influences how the addition of rod-like particles affects the rheological response of a suspension of frictionless non-Brownian spheres to an external shear flow. At fixed values of the total (rods plus spheres) packing fraction, the viscosity of the suspension is reduced by the addition of "short" ( $\leq 2$) rods but is instead increased by the addition of "long" ( $\geq2$) rods. A mechanistic interpretation is provided in terms of packing and excluded-volume arguments.

cond-mat.soft↗

arXiv2023

Molecular-level relation between intra-particle glass transition temperature and stability of colloidal suspensions

In many colloidal suspensions, the dispersed colloidal particles are amorphous solids resulting from vitrification. A crucial open problem is understanding how colloidal stability is affected by the intra-particle glass transition. By dealing with the latter process from a solid-state perspective, we estabilish a proportionality relation between the intra-particle glass transition temperature, $T_{\textrm{g}},$ and the Hamaker constant, $A_\textrm{H},$ of a generic suspension of nanoparticles. It follows that $T_\textrm{g}$ can be used as a convenient parameter (alternative to $A_\textrm{H}$) for controlling the stability of colloidal systems. Within DLVO theory, we show that the novel relationship, connecting $T_\textrm{g}$ to $A_\textrm{H},$ implies the critical coagulation ionic strength (CCIS) to be a monotonically decreasing function of $T_{\textrm{g}}.$ We connect our predictions to recent experimental findings.

cond-mat.soft↗