KINETICS OF CLUSTER GROWTH BY AGGREGATION

The classical problem of the coalescence of isolated species to produc e growing clusters/colloids/polymers by successive statistical encount ers having the same rate constant, is revisited using numerical simula tion for a maximum nuclearity value of a few 10(3) units. The evolutio n with time of the abundance of clusters of a given nuclearity and of the total population, and the distribution of sizes at a given time ar e obtained and compared with models from the literature. A remarkable feature of these curves is that they exhibit parity effects for the nu clearity, even clusters being systematically more abundant than odd on es. For easier comparison with experiments, some simulated curves are presented in the form of an approximated analytical expression: kineti cs of the total population, and of the monomer,dimer and higher oligom ers populations, amplitudes at the maximum and delay for the maximum a s functions of the nuclearity, size distribution at a given time. The validity of the approximations is discussed.