Accessible volume in quenched-annealed mixtures of hard spheres: a geometric decomposition

Kurzidim, Jan; Kahl, Gerhard

doi:10.1080/00268976.2011.556579

Cited by 11 publications

(15 citation statements)

References 43 publications

(72 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hence, the nondecaying part of F s (k, t) must be entirely due to the trapped particles; this fact is reflected in the significant nonrelaxing part of F trap s (k, t). We observe that F trap s (k, t→∞) exhibits a nonmonotonic behaviour, attaining a minimum value at φ m ≃ 0.25, which is close to the percolation transition in the void space [33]. δr 2 free (t) and z free (t)-the latter is presented in Fig.…”

Section: Dynamic Correlation Functionsmentioning

confidence: 58%

“…We employed an algorithm based on a Delaunay tessellation-details are presented in Ref. [33]-in order to identify for a given matrix configuration whether a void constitutes a trap or the percolating void. Using the position of a fluid particle at an arbitrary instance of time, it is thus possible to determine whether the particle in question is "free" or "trapped" (according to the previously-introduced notion).…”

Section: Void Analysismentioning

confidence: 99%

See 1 more Smart Citation

Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

Kurzidim

Coslovich

Kahl

2011

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

Using numerical simulations we study the slow dynamics of a colloidal hard-sphere fluid adsorbed in a matrix of disordered hard-sphere obstacles. We calculate separately the contributions to the single-particle dynamic correlation functions due to free and trapped particles. The separation is based on a Delaunay tessellation to partition the space accessible to the centres of fluid particles into percolating and disconnected voids. We find that the trapping of particles into disconnected voids of the matrix is responsible for the appearance of a nonzero long-time plateau in the single-particle intermediate scattering functions of the full fluid. The subdiffusive exponent z, obtained from the logarithmic derivative of the mean squared displacement, is essentially unaffected by the motion of trapped particles: close to the percolation transition, we determined z approximately = 0.5 for both the full fluid and the particles moving in the percolating void. Notably, the same value of z is found in single-file diffusion and is also predicted by mode-coupling theory along the diffusion-localization line. We also reveal subtle effects of dynamic heterogeneity in both the free and the trapped component of the fluid particles, and discuss microscopic mechanisms that contribute to this phenomenon.

show abstract

Section: Dynamic Correlation Functionsmentioning

confidence: 58%

Section: Void Analysismentioning

confidence: 99%

Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

Kurzidim

Coslovich

Kahl

2011

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

show abstract

“…We conclude that the strong deformability of the particles which can either lead to center-to-center distances between particles that are smaller than σ, but also to separations that are larger than σ. Possibly the particles can also explore the available space inside the pores of the matrix more efficiently as they can access in their deformed shape spaces that otherwise would be inaccessible for rigid, spherical particles; however, a closer analysis of this conjecture would require a detailed geometric analysis of the voids inside the matrix in terms of a Delaunay decomposition [35], an investigation which would clearly bypass the limitations of this contribution. Of course also the density parameters, Φ f and Φ m , have their impact on the shape of the radial distribution function.…”

Section: The Radial Distribution Functions Across the Pathwaysmentioning

confidence: 99%

Deformable hard particles particles confined in a disordered porous matrix

Stadik,

Kahl

2021

Preprint

Self Cite

View full text Add to dashboard Cite

With suitably designed Monte Carlo simulations we have investigated the properties of mobile, impenetrable, yet deformable particles that are immersed into a porous matrix, the latter one realized via a frozen configuration of spherical particles. By virtue of a model put forward by Batista and Miller [Phys. Rev. Lett. 105, 088305 (2010)] the fluid particles can change under the impact of their surrounding (i.e., either other fluid particles or the matrix) their shape within the class of ellipsoids of revolution; such a change in shape is related to an energy change which is fed into suitably defined selection rules in the deformation "moves" of the Monte Carlo simulations. This concept represents a simple, yet powerful model of realistic, deformable molecules with complex internal structures (such as dendrimers or polymers). For the evaluation of the properties of the system we have used the well-known quenched-annealed protocol (with its characteristic double average prescription) and have analysed the simulation data in terms of static properties (radial distribution function and aspect ratio distribution of the ellipsoids) and dynamic features (notably the mean squared displacement). Our data provide evidence that the degree of deformability of the fluid particles has a distinct impact on the aforementioned properties of the system.

show abstract

“…Those three discs become members of the pore and their centers correspond to the vertices of a Delaunay triangle. 9,65,66 The pore is concentric to a circumcircle of the Delaunay triangle with a pore diameter σ p ( Figure 2). Discs that share an edge of the Delaunay triangle are the nearest neighbor (NN) discs to each other.…”

Section: Definitions and Lifetimes Of Pores And Cagesmentioning

confidence: 99%

Dynamics and spatial correlation of voids in dense two dimensional colloids

Kim

Sung

2014

The Journal of Chemical Physics

View full text Add to dashboard Cite

Two dimensional (2D) colloids show interesting phase and dynamic behaviors. In 2D, there is another intermediate phase, called hexatic, between isotropic liquid and solid phases. 2D colloids also show strongly correlated dynamic behaviors in hexatic and solid phases. We perform molecular dynamics simulations for 2D colloids and illustrate how the local structure and dynamics of colloids near phase transitions are reflected in the spatial correlations and dynamics of voids. Colloids are modeled as hard discs and a void is defined as a tangent circle (a pore) to three nearest hard discs. The variation in pore diameters represents the degree of disorder in voids and decreases sharply with the area fraction (ϕ) of colloids after a hexagonal structural motif of colloids becomes significant and the freezing transition begins at ϕ ≈ 0.7. The growth of ordered domains of colloids near the phase transition is captured in the spatial correlation functions of pores. We also investigate the topological hopping probability and the topological lifetime of colloids in different topological states, and find that the stability of different topological states should be related to the size variation of local pores: colloids in six-fold states are surrounded by the most ordered and smallest pores with the longest topological lifetime. The topological lifetime of six-fold states increases by about 50 times as ϕ increases from liquid to hexatic to solid phases. We also compare four characteristic times in order to understand the slow and unique dynamics of two dimensional colloids: a caging time (τ(c)), a topological lifetime (τ(top)), a pore lifetime (τ(p)), and a translational relaxation time (τ(α)).

show abstract

Accessible volume in quenched-annealed mixtures of hard spheres: a geometric decomposition

Cited by 11 publications

References 43 publications

Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

Deformable hard particles particles confined in a disordered porous matrix

Dynamics and spatial correlation of voids in dense two dimensional colloids

Contact Info

Product

Resources

About