Transport of spherical colloids in layered phases of binary mixtures with rod-like particles

Piedrahita, Mauricio; Cuetos, Alejandro; Martínez–Haya, Bruno

doi:10.1039/c4sm02865a

Cited by 12 publications

(16 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The dynamics of rods in the two liquid crystal phases is significantly different and influenced by the layered structure that hampers their diffusion in the direction ofn in the Sm phase. In the N phase, the parallel MSD is larger than the perpendicular MSD from short to long times, as also found elsewhere [30,32]. By contrast, in the Sm phase, this behavior is only observed at short times, when the rods are still diffusing in the cage formed by their nearest neighbors.…”

Section: Resultssupporting

confidence: 67%

See 1 more Smart Citation

Equivalence of Brownian dynamics and dynamic Monte Carlo simulations in multicomponent colloidal suspensions

Cuetos

Patti

2015

Phys. Rev. E

Self Cite

View full text Add to dashboard Cite

We propose a simple but powerful theoretical framework to quantitatively compare Brownian dynamics (BD) and dynamic Monte Carlo (DMC) simulations of multicomponent colloidal suspensions. By extending our previous study focusing on monodisperse systems of rodlike colloids, here we generalize the formalism described there to multicomponent colloidal mixtures and validate it by investigating the dynamics in isotropic and liquid crystalline phases containing spherical and rodlike particles. In order to investigate the dynamics of multicomponent colloidal systems by DMC simulations, it is key to determine the elementary time step of each species and establish a unique timescale. This is crucial to consistently study the dynamics of colloidal particles with different geometry. By analyzing the mean-square displacement, the orientation autocorrelation functions, and the self part of the van Hove correlation functions, we show that DMC simulation is a very convenient and reliable technique to describe the stochastic dynamics of any multicomponent colloidal system. Our theoretical formalism can be easily extended to any colloidal system containing size and/or shape polydisperse particles.

show abstract

Section: Resultssupporting

confidence: 67%

“…A peculiar feature of rods' diffusion in the Sm phase is their tendency to rattle around in a given layer until they jump to a neighboring layer [13]. A similar behavior has also been observed in binary mixtures of rods and spheres, with the latter preferentially hopping between the interlayer spaces [30]. In Fig.…”

Section: Resultssupporting

confidence: 65%

Equivalence of Brownian dynamics and dynamic Monte Carlo simulations in multicomponent colloidal suspensions

Cuetos

Patti

2015

Phys. Rev. E

Self Cite

View full text Add to dashboard Cite

show abstract

“…The opposite tendency is observed in nematic phases of oblate particles. Nevertheless, in positionally order smectic and columnar LCs, the layer-to-layer and column-to-column diffusion results to be significantly reduced and becomes slower than the in-layer or in-column diffusion [25][26][27][28][29][30] .…”

Section: Introductionmentioning

confidence: 99%

Brownian dynamics simulations of oblate and prolate colloidal particles in nematic liquid crystals

Morillo

Patti

Cuetos

2019

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

It is well known that understanding the transport properties of liquid crystals (LCs) is crucial to optimise their performance in a number of technological applications. In this work, we analyse the effect of shape anisotropy on the diffusion of rod-like and disk-like particles by Brownian dynamics simulations. To this end, we compare the dynamics of prolate and oblate nematic LCs incorporating particles with the same infinite-dilution translational or rotational diffusion coefficients. Under these conditions, which are benchmarked against the standard case of identical aspect ratios, we observe that prolate particles display faster dynamics than oblate particles at short and long timescales. Nevertheless, when compared at identical infinite-dilution translational diffusion coefficients, oblate particles are faster than their prolate counterparts at short-to-intermediate timescales, which extend over almost three time decades. Both oblate and prolate particles exhibit an anisotropic diffusion with respect to the orientation of the nematic director. More specifically, prolate particles show a fast diffusion in the direction parallel to the nematic director, while their diffusion in the direction perpendicular to it is slower. By contrast, the diffusion of oblate particles is faster in the plane perpendicular to the nematic director. Finally, in the light of our recent study on the longtime Gaussian and Fickian diffusion in nematic LCs, we map the decay of the autocorrelation functions and their fluctuations over the timescales of our simulations to ponder the existence of mobile clusters of particles and the occurrence of collective motion.

show abstract

“…In addition, the relatively moderate packing fractions of nematics, as compared to smectic or columnar LC phases, allow to more easily achieve the asymptotic limit of long time scales and distinguish it from the non-Gaussian signature of the caging effect at shorter times. Previous works observed the existence of deviations of G s (r, t) from a Gaussian distribution in smectic [15][16][17] and columnar [18,19] LCs, where the diffusion perpendicular, respectively, to the layers and columns is especially slow and determining the onset of the long time diffusive regime not always straightforward.…”

mentioning

confidence: 97%

Fickian yet non-Gaussian diffusion is not ubiquitous in soft matter

2018

Self Cite

View full text Add to dashboard Cite

Recent studies unveiled the Fickian yet non-Gaussian (FNG) dynamics of many soft matter systems and suggested this phenomenon as a general characteristic of the diffusion in complex fluids. In particular, it was shown that the distribution of particle displacements in Fickian diffusion is not necessarily Gaussian, and thus the Einstein and Smoluchowski theory describing the Brownian motion of individual objects in a fluid would not be applicable. In this Letter, we investigate whether the FNG dynamics so far reported in gels, granular materials, biological and active matter systems, is also a distinctive feature of colloidal liquid crystals. To this end, we perform Brownian Dynamics simulations of oblate and prolate colloidal particles in the nematic phase. We detect a normal and Gaussian dynamics at short and long time scales, whereas, at intermediate time scales, a non-Fickian and non-Gaussian dynamics is found. Additionally, we revisit the nature of the decay of the self-van Hove correlation function, Gs(r, t), which is here approximated with an ellipsoidal, rather than spherical, Gaussian distribution. The new expression that we propose is able to correctly assess the Gaussian dynamics in inherently anisotropic systems, like liquid crystals, where the standard Gaussian approximation of Gs(r, t) would fail.

show abstract

Transport of spherical colloids in layered phases of binary mixtures with rod-like particles

Cited by 12 publications

References 44 publications

Equivalence of Brownian dynamics and dynamic Monte Carlo simulations in multicomponent colloidal suspensions

Equivalence of Brownian dynamics and dynamic Monte Carlo simulations in multicomponent colloidal suspensions

Brownian dynamics simulations of oblate and prolate colloidal particles in nematic liquid crystals

Fickian yet non-Gaussian diffusion is not ubiquitous in soft matter

Contact Info

Product

Resources

About