Structural and dynamical analysis of monodisperse and polydisperse colloidal systems

Marianna Yiannourakou, Ioannis Economou, Ioannis A. Bitsanis

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We present a semigrand ensemble Monte Carlo and Brownian dynamics simulation study of structural and dynamical properties of polydisperse soft spheres interacting via purely repulsive power-law potentials with a varying degree of "softness." Comparisons focus on crystal and amorphous phases at their coexistence points. It is shown through detailed structural analysis that as potential interactions soften, the "quality of crystallinity" of both monodisperse and polydisperse systems deteriorates. In general, polydisperse crystalline phases are characterized by a more ordered structure than the corresponding monodisperse ones (i.e., for the same potential softness). This counter-intuitive feature originates partly from the fact that particles of different sizes may be accommodated more flexibly in a crystal structure and from the reality that coexistence (osmotic) pressure is substantially higher for polydisperse systems. These trends diminish for softer potentials. Potential softness eventually produces substitutionally disordered crystals. However, substitutional order is apparent for the hard-spherelike interactions. Diffusionwise, crystals appear quite robust with a slight difference in the vibrational amplitudes of small and large particles. This difference, again, diminishes with potential softness. Overcrowding in amorphous polydisperse suspensions causes "delayed" diffusion at intermediate times.

Original languageEnglish
Article number224901
JournalJournal of Chemical Physics
Volume133
Issue number22
DOIs
Publication statusPublished - 14 Dec 2010
Externally publishedYes

Fingerprint

structural analysis
softness
Crystals
Structural analysis
Suspensions
Crystal structure
Crystalline materials
crystals
osmosis
Computer simulation
crystallinity
counters
interactions
trends
crystal structure
causes
simulation

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Structural and dynamical analysis of monodisperse and polydisperse colloidal systems. / Yiannourakou, Marianna; Economou, Ioannis; Bitsanis, Ioannis A.

In: Journal of Chemical Physics, Vol. 133, No. 22, 224901, 14.12.2010.

Research output: Contribution to journalArticle

@article{1aeb1f0d7b664a31aa1b158318ba9144,
title = "Structural and dynamical analysis of monodisperse and polydisperse colloidal systems",
abstract = "We present a semigrand ensemble Monte Carlo and Brownian dynamics simulation study of structural and dynamical properties of polydisperse soft spheres interacting via purely repulsive power-law potentials with a varying degree of {"}softness.{"} Comparisons focus on crystal and amorphous phases at their coexistence points. It is shown through detailed structural analysis that as potential interactions soften, the {"}quality of crystallinity{"} of both monodisperse and polydisperse systems deteriorates. In general, polydisperse crystalline phases are characterized by a more ordered structure than the corresponding monodisperse ones (i.e., for the same potential softness). This counter-intuitive feature originates partly from the fact that particles of different sizes may be accommodated more flexibly in a crystal structure and from the reality that coexistence (osmotic) pressure is substantially higher for polydisperse systems. These trends diminish for softer potentials. Potential softness eventually produces substitutionally disordered crystals. However, substitutional order is apparent for the hard-spherelike interactions. Diffusionwise, crystals appear quite robust with a slight difference in the vibrational amplitudes of small and large particles. This difference, again, diminishes with potential softness. Overcrowding in amorphous polydisperse suspensions causes {"}delayed{"} diffusion at intermediate times.",
author = "Marianna Yiannourakou and Ioannis Economou and Bitsanis, {Ioannis A.}",
year = "2010",
month = "12",
day = "14",
doi = "10.1063/1.3506576",
language = "English",
volume = "133",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics Publising LLC",
number = "22",

}

TY - JOUR

T1 - Structural and dynamical analysis of monodisperse and polydisperse colloidal systems

AU - Yiannourakou, Marianna

AU - Economou, Ioannis

AU - Bitsanis, Ioannis A.

PY - 2010/12/14

Y1 - 2010/12/14

N2 - We present a semigrand ensemble Monte Carlo and Brownian dynamics simulation study of structural and dynamical properties of polydisperse soft spheres interacting via purely repulsive power-law potentials with a varying degree of "softness." Comparisons focus on crystal and amorphous phases at their coexistence points. It is shown through detailed structural analysis that as potential interactions soften, the "quality of crystallinity" of both monodisperse and polydisperse systems deteriorates. In general, polydisperse crystalline phases are characterized by a more ordered structure than the corresponding monodisperse ones (i.e., for the same potential softness). This counter-intuitive feature originates partly from the fact that particles of different sizes may be accommodated more flexibly in a crystal structure and from the reality that coexistence (osmotic) pressure is substantially higher for polydisperse systems. These trends diminish for softer potentials. Potential softness eventually produces substitutionally disordered crystals. However, substitutional order is apparent for the hard-spherelike interactions. Diffusionwise, crystals appear quite robust with a slight difference in the vibrational amplitudes of small and large particles. This difference, again, diminishes with potential softness. Overcrowding in amorphous polydisperse suspensions causes "delayed" diffusion at intermediate times.

AB - We present a semigrand ensemble Monte Carlo and Brownian dynamics simulation study of structural and dynamical properties of polydisperse soft spheres interacting via purely repulsive power-law potentials with a varying degree of "softness." Comparisons focus on crystal and amorphous phases at their coexistence points. It is shown through detailed structural analysis that as potential interactions soften, the "quality of crystallinity" of both monodisperse and polydisperse systems deteriorates. In general, polydisperse crystalline phases are characterized by a more ordered structure than the corresponding monodisperse ones (i.e., for the same potential softness). This counter-intuitive feature originates partly from the fact that particles of different sizes may be accommodated more flexibly in a crystal structure and from the reality that coexistence (osmotic) pressure is substantially higher for polydisperse systems. These trends diminish for softer potentials. Potential softness eventually produces substitutionally disordered crystals. However, substitutional order is apparent for the hard-spherelike interactions. Diffusionwise, crystals appear quite robust with a slight difference in the vibrational amplitudes of small and large particles. This difference, again, diminishes with potential softness. Overcrowding in amorphous polydisperse suspensions causes "delayed" diffusion at intermediate times.

UR - http://www.scopus.com/inward/record.url?scp=78650363263&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78650363263&partnerID=8YFLogxK

U2 - 10.1063/1.3506576

DO - 10.1063/1.3506576

M3 - Article

C2 - 21171696

AN - SCOPUS:78650363263

VL - 133

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

IS - 22

M1 - 224901

ER -