tion of large rod-like structures, chains must not be fully overlapping, allowing for the growth of the aggregate in a brickwork-like fashion. For non-overlapping chains to lead to significant growth of aggregates, it is necessary that these incompletely overlapped chain pairs be sufficiently stable that they are inseparable, or at least do not separate on the time scale of further aggregation, such that they become effectively trapped as additional chains are incorporated into the aggregate.