Related Experiment Video
Updated: May 20, 2026
10:17
Patterning of Microorganisms and Microparticles through Sequential Capillarity-assisted Assembly
Published on: November 4, 2021
Particle Monte Carlo simulation of string-like colloidal assembly in two and three dimensions
Yuki Norizoe1, Toshihiro Kawakatsu
1Department of Physics, Tohoku University, 980-8578 Sendai, Japan. norizoe@cmpt.phys.tohoku.ac.jp
The Journal of Chemical Physics
|July 19, 2012
Summary
Polymer-grafted colloidal particles self-assemble into string-like structures without attraction. This phenomenon, observed via molecular Monte Carlo simulations, relates to percolation and phase transitions.
Area of Science:
- Soft Matter Physics
- Colloidal Science
- Computational Materials Science
Background:
- Understanding the self-assembly of colloidal particles is crucial for designing novel materials.
- Polymer-grafted colloids offer tunable interactions, but their phase behavior, especially without attraction, requires further investigation.
Purpose of the Study:
- To simulate the structural phase behavior of polymer-grafted colloidal particles using a purely repulsive interparticle potential.
- To investigate the formation of string-like assemblies and their relationship to percolation phenomena.
Main Methods:
- Molecular Monte Carlo (MMC) simulations were employed in the canonical ensemble.
- A previously validated repulsive square-step interparticle potential was used.
- Simulations were conducted in both two and three dimensions.
Main Results:
- Particles self-assembled into string-like structures at low temperatures and high densities, despite the absence of interparticle attraction.
- The string-like assembly was linked to percolation phenomena, with phase diagrams constructed by analyzing cluster size and average string length.
- The average string length diverged at the intersection of melting and percolation transition lines, analogous to critical points in Ising spin systems.
Conclusions:
- Purely repulsive interactions in polymer-grafted colloids can drive self-assembly into ordered string-like structures.
- The observed phase behavior is governed by percolation and exhibits similarities to order-disorder transitions in magnetic systems.
- This study provides insights into the fundamental mechanisms governing colloidal self-assembly and phase transitions.
Related Concept Videos
01:29The Colloidal State
The formation of a colloidal system is exemplified by an aqueous solution containing Cl− ions is introduced to another containing Ag+ ions, resulting in the precipitation of solid AgCl as extremely tiny crystals. Instead of settling out as a filterable precipitate, these crystals remain suspended in the liquid, showcasing a colloidal system.A colloidal system involves colloidal particles within the approximate range of 1 to 1000 nm in at least one dimension, dispersed in a medium called the...
01:17Colloids and Suspensions
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles visible to the naked eye or seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. The suspended particles in a suspension settle out after some time of mixing. The separation of particles from a suspension is...
02:00Molecular Models
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
01:34The Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
03:22Colloids
Children at play often make suspensions such as mixtures of mud and water, flour and water, or a suspension of solid pigments in water known as tempera paint. These suspensions are heterogeneous mixtures composed of relatively large particles that are visible to the naked eye or can be seen with a magnifying glass. They are cloudy, and the suspended particles settle out after mixing. On the other hand, a solution is a homogeneous mixture in which no settling occurs and in which the dissolved...