Measurement of Fractal Aggregates of Polydisperse Particles Using Small-Angle Light Scattering

• Published in: Journal of colloid and interface science Vol. 221; no. 2; pp. 186 - 194
• Main Authors: Bushell, Graeme, Amal, Rose
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 15.01.2000; Elsevier
• Subjects: aggregation; Chemistry; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Exact sciences and technology; fractal dimension; General and physical chemistry; kinetics scaling; mass scaling; polydispersity; scattering; fractal dimension; kinetics scaling; mass scaling; aggregation; scattering; polydispersity; Hematite; Iron Oxides; Small angle light scattering; Fractal dimension; Hydrosol; Transition metal Compounds; Polydispersed particle; Aggregate; Colloidal sol
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1006/jcis.1999.6532

The effect of primary particle polydispersity on the structure of fractal aggregates has been investigated through the salt-induced, diffusion-limited aggregation of mixtures of hematite. The fractal dimension was determined experimentally using three independent methods: q dependence of static light scattering, kinetic scaling, and correlation of aggregate mass and linear size both determined from Guinier scattering. The fractal dimensions Df obtained were 1.75±0.03, 1.76±0.03, and 1.70±0.05, respectively. The use of a previously derived fractal mean particle size was validated in allowing data collapse to master curves for the aggregation kinetics data. The fractal mean particle size is shown to have general utility by taking a number weighting to describe polydisperse aggregation kinetics and a mass weighting to describe small q scattering behavior.