Local Structure Evolution in Particle Network Formation Studied by Brownian Dynamics Simulation

• Published in: Journal of colloid and interface science Vol. 231; no. 2; pp. 337 - 350
• Main Author: Hütter, Markus
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.11.2000; Elsevier
• Subjects: bond angle distribution; Brownian dynamics; Chemistry; coagulation; Colloidal state and disperse state; colloids; computer simulation; Exact sciences and technology; fractal dimension; gelation; General and physical chemistry; local structure; pair correlation; particle gel; particle network; Physical and chemical studies. Granulometry. Electrokinetic phenomena; gelation; particle gel; particle network; local structure; Brownian dynamics; fractal dimension; computer simulation; bond angle distribution; colloids; pair correlation; coagulation; Pair correlation function; Brownian motion; Local structure; Interparticle interaction; Fractal dimension; Computer simulation; Gelation; Bond angle; Coagulation; Theoretical study; Angular distribution; Colloid particle
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.2000.7150

The effect of solid content and colloidal interactions on the structure of forming networks of colloidal particles is studied by Brownian dynamics simulation. The different situations are compared in terms of the pair distribution function and the distribution of nearest neighbors around each particle. The results indicate that, in fast coagulation, the higher solid contents lead to a freezing-in of the liquid structure. Nevertheless, this effect can be reduced substantially by the introduction of a shallow secondary minimum and an energy barrier in the interaction potential. However, the structures resulting from such slow coagulation show a substantial degree of porosity, larger than those produced at the same solid content but by fast coagulation. It is also shown how the porosity (defined on a few particle diameters) is reflected in the distribution of nearest neighbors around the center particle, i.e., the very local conformation in the particle network. Fractal analysis shows that, at the relatively high volume fractions considered in this study, no intermediate fractal regime exists.