Universality in colloid aggregation

THE aggregation of colloidal particles is of fundamental importance in colloid science and its applications. The recent application of scaling concepts1,2 has resulted in a much deeper understanding of the structure of colloidal aggregates and the kinetics of their formation. Two distinct, limiting regimes of irreversible colloid aggregation have been identified3. Diffusion-limited colloid aggregation occurs when there is negligible repulsive force between the colloidal particles, so that the aggregation rate is limited solely by the time taken for clusters to encounter each other by diffusion. Reaction-limited colloid aggregation occurs when there is still a substantial, but not insurmountable, repulsive force beween the particles, so that the aggregation rate is limited by the time taken for two clusters to overcome this repulsive barrier by thermal activation. These regimes correspond to the limiting cases of rapid and slow colloid aggregation that have long been recognized in colloid science4. An intriguing possibility suggested by recent work is that each of these limiting regimes of colloid aggregation is universal, independent of the chemical details of the particular colloid system. Here we investigate the aggregation of three chemically different colloidal systems under both diffusion-limited and reaction-limited aggregation conditions. A scaling analysis of light-scattering data is used to compare the behaviour and provides convincing experimental evidence that the two regimes of aggregation are indeed universal.

[1]  Hill,et al.  Ultrahigh-energy cosmic-ray spectrum. , 1985, Physical review. D, Particles and fields.

[2]  Dale W. Schaefer,et al.  Fractal geometry of colloidal aggregates , 1984 .

[3]  George B. Benedek,et al.  Measurement of the Cluster Size Distributions for High Functionality Antigens Cross-Linked by Antibody , 1980 .

[4]  Rémi Jullien,et al.  Scaling of Kinetically Growing Clusters , 1983 .

[5]  Martin,et al.  Aggregation in colloidal gold. , 1989, Physical review. A, General physics.

[6]  D. Cannell,et al.  Restructuring of colloidal silica aggregates. , 1986, Physical review letters.

[7]  George W. Mulholland,et al.  Light scattering from simulated smoke agglomerates , 1988 .

[8]  R. J. Cohen,et al.  Equilibrium and kinetic theory of polymerization and the sol-gel transition , 1982 .

[9]  P. Meakin,et al.  Translational friction coefficient of diffusion limited aggregates , 1984 .

[10]  Witten,et al.  Universal kinetics in reaction-limited aggregation. , 1987, Physical review letters.

[11]  Tamás Vicsek,et al.  Dynamic Scaling for Aggregation of Clusters , 1984 .

[12]  Klein,et al.  Effect of rotational diffusion on quasielastic light scattering from fractal colloid aggregates. , 1988, Physical review. A, General physics.

[13]  Jens Feder,et al.  Scaling behavior and cluster fractal dimension determined by light scattering from aggregating proteins , 1984 .

[14]  Wiltzius,et al.  Hydrodynamic behavior of fractal aggregates. , 1987, Physical review letters.

[15]  Huang,et al.  Limits of the fractal dimension for irreversible kinetic aggregation of gold colloids. , 1985, Physical review letters.

[16]  Ernst,et al.  Dynamic scaling in the kinetics of clustering. , 1985, Physical review letters.

[17]  Mártin.  Slow aggregation of colloidal silica. , 1987, Physical review. A, General physics.

[18]  D. Horne.  Determination of the fractal dimension using turbidimetric techniques. Application to aggregating protein systems , 1987 .

[19]  D. Weitz,et al.  Fractal structures formed by kinetic aggregation of aqueous gold colloids , 1984 .

[20]  Vicsek,et al.  Dynamic cluster-size distribution in cluster-cluster aggregation: Effects of cluster diffusivity. , 1985, Physical review. B, Condensed matter.

[21]  W. Hess,et al.  On the hydrodynamic behavior of colloidal aggregates , 1986 .

[22]  R. Botet,et al.  Aggregation and Fractal Aggregates , 1987 .

[23]  Meakin,et al.  Structure and dynamics of reaction-limited aggregation. , 1987, Physical review. A, General physics.

[24]  J. W. Goodwin,et al.  Scaling behaviour of the rheology of aggregate networks formed from colloidal particles , 1988 .

[25]  P. Meakin.  Formation of fractal clusters and networks by irreversible diffusion-limited aggregation , 1983 .

[26]  Weitz,et al.  Dynamic scaling of cluster-mass distributions in kinetic colloid aggregation. , 1986, Physical review letters.