Similarity of wet granular packing to gels

Abstract

To date, there is still no general consensus on the fundamental principle that governs glass transition. Colloidal suspensions are ordinarily utilized as model systems to study the dynamical arrest mechanisms in glass or gels. Here, we tackle the problem using athermal granular particles. Slow dynamics and structural evolution of granular packing upon tapping are monitored by fast X-ray tomography. When the packing are wet and short-range attractive interactions exist, we find a large amount of locally favoured structures with fivefold symmetry, which bear great structural similarity to colloidal gels. In addition, these structures are almost absent in dry packing with similar packing fractions. The study leads strong support for the geometrical frustration mechanism for dynamic arrest in both thermal and athermal systems with attractive interactions. It also suggests nontrivial structural mechanism, if exists, for dynamic arrest in systems with purely repulsive interactions.

Random loose packing of small particles with liquid cohesion

“…implies that when the surface tension approaches 0, the coordination number Z ≈ 6 is close to Z RCP rather than Z RLP , while Z ≈ 3.8 is close to Z RLP rather than Z ALP = 2 as the surface tension dominates. It is consistent with the fact that wet grains have a larger coordination number than dry adhesive or nonadhesive grains considering the same packing fraction …”

“…It reduces the inertia of particles and leads to a looser packing compared with dry particles. In addition, Li et al experimentally investigated the packing structure of water wetted grains using fast X‐ray tomography and obtained a packing fraction of 0.386, which is well consistent with the prediction of Eq. deduced in our work.…”

“…Seville et al compared different interparticle forces and concluded that the capillary force could be several orders of magnitude stronger than gravity, electrostatics, and van der Waals forces, thus the local and global properties of random packing of granular materials are also suggested to be significantly influenced by the addition of liquid. For example, Li et al observed a large number of locally favored structures in the packings of wet grains, which are similar to those in colloidal gels and are almost absent in the packings of dry grains. To obtain the details inside a packing from both macroscopic and microscopic viewpoints, experimental studies are generally either quite difficult or expensive.…”

Five-fold symmetry as indicator of dynamic arrest in metallic glass-forming liquids

“…Recently, by means of advanced instruments, the five-fold symmetry has been experimentally confirmed to exist in liquids 5 6 7 8 9 10 , colloids 11 12 , granular particles 13 , hard-sphere glasses 14 and metallic glasses (MGs) 15 . Plenty of studies from the perspective of local potential energy minimum and orientational order parameters have been devoted to the effect of the five-fold symmetry on properties, especially in colloidal and granular systems 11 13 16 17 . It is found that because of the incompatibility with translational symmetry, the five-fold symmetry results in severe frustration and hinders crystallization in colloids 12 16 .…”

Origin of Noncubic Scaling Law in Disordered Granular Packing

“…Therefore, such phenomenon is directly related to jamming phenomenon and might be universal near the jamming criticality [23,24]. In the experiment, we used synchrotron X-ray CT techniques to obtain the packing structures of packing with a wide range of packing fractions  [25][26][27][28][29][30][31][32][33][34] (see Supplemental Material [35]). In the following, we use the average particle diameter as a unit of length.…”