Gel formation through reversible and irreversible aggregation.

We study the kinetics of formation of branched loopless structures in mixtures of particles with different shapes and functionalities. These systems are treated with the appropriate Smoluchowski rate equations, including condensation and fragmentation terms, and it is shown that it is possible to provide a parameter-free description of the assembly process, including the limit of irreversible aggregation at low temperatures. Using dynamics simulations we provide evidence of a connection between physical and chemical gelation in low-valence particle systems, and the possibility of relating ageing time with temperature.