Scattering behavior of restructured aggregates: A simulation study

Simulations of diffusion-limited cluster-cluster aggregation (DLCA) with no restructuring, full restructuring, and partial restructuring have been per formed. The scattering patterns produced from these aggregates have been si mulated using the Rayleigh-Gans-Debye approximation. Pure DLCA aggregates p roduced a scattering pattern with the slope of the fractal region being abo ut -1.8. In contrast, the slope of the fractal region of the scattering pat tern for fully restructured aggregates was about -2.1, indicating an increa se in fractal dimension. Partial restructuring at large length scales produ ced an upward turn in the scattering pattern at low qr(o), while at high qr (o) the fractal section of the pure DLCA aggregate was retained. This last result was expected and is consistent with the results and postulations of several other workers. This simulation shows that the type of scattering pa ttern often obtained from orthokinetic or sheared aggregation can be produc ed by restructuring of aggregates at large length scales. (C) 2001 Academic Press.