Kinetic growth of field-oriented chains in dipolar colloidal solutions

Experimental studies on the irreversible growth of field-induced chains of dipolar particles suggest an asymptotic power-law behavior of several relevant quantities. We introduce a Monte Carlo model of chain growth that explicitly incorporates the anisotropic diffusion characteristic of a rod-like o...

Descripción completa

Detalles Bibliográficos
Autores: Miguel López, María del Carmen, Pastor-Satorras, R. (Romualdo), 1967-
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1999
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/18851
Acceso en línea:https://hdl.handle.net/2445/18851
Access Level:acceso abierto
Palabra clave:Mecànica estadística
Mètode de Montecarlo
Col·loides
Statistical mechanics
Monte Carlo method
Colloids
Descripción
Sumario:Experimental studies on the irreversible growth of field-induced chains of dipolar particles suggest an asymptotic power-law behavior of several relevant quantities. We introduce a Monte Carlo model of chain growth that explicitly incorporates the anisotropic diffusion characteristic of a rod-like object. Assuming a simple power-law form for the mean cluster size, $S(t) \sim t^z$, the results of our model are in good agreement with the experimental measurements of the dynamic exponent $z$. Nevertheless, an alternative scenario, including logarithmic corrections to the standard power-law behavior, provides a better and more insightful interpretation of the anomalous dynamic exponent. In contrast to some experimental findings, we do not observe any dependence of the exponents on the volume fraction of particles $\phi$. Finite-size effects are also explored by simulating very long time evolutions or highly concentrated systems. Two different behaviors are found, namely, saturation and a crossover to a quasi one-dimensional regime.