Dynamical arrest in adhesive hard-sphere dispersions driven by rigidity percolation

Abstract

One major goal in condensed matter is identifying the physical mechanisms that lead to arrested states of matter, especially gels and glasses. The complex nature and microscopic details of each particular system are relevant. However, from both scientific and technological viewpoints, a general, consistent and unified definition is of paramount importance. Through Monte Carlo computer simulations of states identified in experiments, we demonstrate that dynamical arrest in adhesive hard-sphere dispersions is the result of rigidity percolation with coordination number 〈n(b)〉 equal to 2.4. This corresponds to an established mechanism leading to mechanical transitions in network-forming materials [Phys. Rev. Lett. 54, 2107 (1985)]. Our findings connect the concept of critical gel formation in colloidal suspensions with short-range attractive interactions to the universal concept of rigidity percolation. Furthermore, the bond, angular, and local distributions along the gelation line are explicitly studied in order to determine the topology of the structure at the critical gel state.

Probing Colloidal Gels at Multiple Length Scales: The Role of Hydrodynamics

“…However, a more diverse range of systems including granular matter [12], phase-demixing oxides [13], and metallic glassformers [14] also exhibit gelation. The mechanical properties of gels are influenced by their structure both locally [15][16][17][18] and at a global level through percolation of particles [19] and clusters [20], network topology [21], and confinement [22].…”

Local structure of percolating gels at very low volume fractions

“…In order to predict the mechanical properties of gels, it is important to know both their local [13][14][15] and global [16][17][18] structure, but a deep understanding of both remains today a challenge. For example, in the very dilute limit, the study of gel formation via molecular dynamics is challenged by the very long times required to form aggregates, with equilibration times that easily exceed 10 8 integration steps 19 .…”

Range effect on percolation threshold and structural properties for short-range attractive spheres

“…12,42 The liquid-liquid phase separation lines with λ = 1.01 and λ = 1.05 are derived from Monte Carlo simulation. 27,32 For different interaction ranges, employing the definition of contact cluster and the spanning rule mentioned above, we determine the three groups of contact PTs. The loci of PTs form the percolation boundary (percolation line), which separates the phase diagram into a percolated and an unpercolated part.…”

“…The isoline for ⟨z⟩ = 2, regarded as a good approximation of the contact percolation boundary predicted by mean field theory, 27,47 is plotted in the phase diagram shown in Fig. 2(b).…”

“…23,24 In addition, inside the percolated regime, when the system is further compressed or quenched, dynamical arrest and gelation of colloidal particles could occur. 13,[16][17][18][25][26][27] Thus, in-depth research on percolation in colloidal system is of great significance in many fields of science and technology.…”