Details

Autor(en) / Beteiligte

• Piechowiak, M. A
• Videcoq, A
• Ferrando, R
• Bochicchio, D
• Pagnoux, C
• Rossignol, F

Titel

Aggregation kinetics and gel formation in modestly concentrated suspensions of oppositely charged model ceramic colloids: a numerical study

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2012-01, Vol.14 (4), p.1431-1439

Ort / Verlag

Cambridge: Royal Society of Chemistry

Erscheinungsjahr

2012

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Aggregation kinetics and gel formation in aqueous suspensions that undergo heteroaggregation are studied by means of Brownian dynamics simulations. The simulated system, described in a previous paper [M. A. Piechowiak, A. Videcoq, F. Rossignol, C. Pagnoux, C. Carrion, M. Cerbelaud, R. Ferrando, Langmuir , 2010, 26 (15), 1254012547.], is constituted of two kinds of synthesized, almost equally sized colloids: silica particles that are negatively charged and alumina-coated silica particles that are positively charged. The interactions between colloids are modeled by the DLVO potential. Several compositions are analyzed, from silica-rich to alumina-rich cases. The particle volume fraction is varied in the range 612%. The study of the aggregation kinetics allows us to clarify the effect of those variations on the clustering process. Gelation is analyzed by detection of spanning clusters in each x -, y -, z -direction of the cubic simulation box. Percolating networks start to be observed from = 7%, a low value of the volume fraction close to the solid volume fraction experimentally measured in sediments of those suspensions. The percolation threshold, in terms of colloid volume fraction, is investigated by means of Brownian simulations, exhibiting the influence of the mass ratio R between the two kinds of colloids.