The Impotence of Non-Brownian Particles on the Gel Transition of Colloidal Suspensions

Abstract

Abstract:The ability to predict transitions in the microstructure of mixed colloidal suspensions is of extreme interest and importance. The data presented here is specific to the case of battery electrode slurries whereby the carbon additive is reported to form strong colloidal gels. Using rheology, we have determined the effect of mixed particle systems on the critical gel transition φ gel . More specifically, we show that the introduction of a high volume fraction of large non-Brownian particles has little to no effect on φ gel . Although φ gel is unchanged, the larger particles do change the shape of the linear viscoelasticity and the nonlinear yielding behavior. There are interesting similarities to the nonlinear behavior of the colloidal gels with trends observed for colloidal glasses. A comparison of experimental data and the prediction from theory shows that the equation presented by Poon et al. is able to quantitatively predict the transition from a fluid state to a gel state.

Rheological Characteristics of 2D Titanium Carbide (MXene) Dispersions: A Guide for Processing MXenes

“…Here, the geometry of the suspended particles has a significant impact on the gelation transition. For instance, the high aspect ratio of the single-layer flakes results in a much lower packing density, which limits the amount of multiparticle interactions that can offer a high elastic modulus . On the other hand, dispersions of multilayer MXenes are expected to form strong gel-like systems much easier, as the random radial morphology of the particles enables reaching higher packing densities at ease.…”

“…For instance, the high aspect ratio of the single-layer flakes results in a much lower packing density, which limits the amount of multiparticle interactions that can offer a high elastic modulus. 46 On the other hand, dispersions of multilayer MXenes are expected to form strong gel-like systems much easier, as the random radial morphology of the particles enables reaching higher packing densities at ease. "Swelling" of the multilayer particles, resulting in multiparticle interactions, and the high amount of friction between the closely packed particles are expected to promote drastic improvements in the elastic modulus once a critical concentration is achieved.…”

Three-Dimensional Visualization of Conductive Domains in Battery Electrodes with Contrast-Enhancing Nanoparticles

“…As shown in Figure , commercial Fe–C nanoparticles were demonstrated as contrast-enhancing agents for XCT by preparing and imaging thin electrodes of Fe-PVDF, graphite-PVDF, and graphite-Fe-PVDF according to literature methods. − With a diameter of 25 nm, the particle size is very similar to conventional conductive carbon nanoparticles. The carbon coating around the Fe additionally provides a surface chemically similar to conventional conductive carbon.…”

Correlating Processing Conditions to Short- and Long-Range Order in Coating and Drying Lithium-Ion Batteries

“…It is known that the rheological response of battery slurries is primarily influenced by the conductive carbon additive network. , Figure S5 shows rheological characterization for the initial slurry used for all coating and drying conditions. The magnitude and frequency-independence of the storage ( G ′) and loss ( G ″) moduli indicate a strong colloidal gel with a spanning network of particles, consistent with previous findings .…”