Comparing the aggregate size (number of monomers) and radius of gyration of the flexible and regular-flexibility backbones shows a slower rate of aggregate growth, and generally more compact structures for the flexible chains than the stiffer regular chains (Fig. ), as expected from the relative rates of folding and aggregation. This behaviour can be attributed to a more rapid collapse into hairpin/toroid structures, which has the twofold effect of reducing the collision rate due to the more compact structures, and giving more compact structures when collisions do occur, as chains may already be partially collapsed. Examining a system with an even lower concentration (2 g/L) showed the same behaviour, with very little multi-chain aggregation observed over the simulated time period (Fig. ). While there was still a brief initial aggregation period, during which chains that were initially positioned close to each other were able to aggregate prior to folding, little aggregation was observed after this point with the average aggregate size remaining well below 2 over the entire simulation period. Although multi-chain aggregation is not completely prevented at this lower concentration, it is greatly suppressed and could be expected to lead to different final aggregate properties, as observed experimentally. The lower radius of gyration of the flexible chains in the poor solvent observed in Fig. could be attributed both less aggregation than for the regular-flexibility backbone and more compact aggregates even when consisting of many chains. From the behaviour in Fig. , the flexible-chain aggregates were generally smaller (contained fewer polymer chains) than those with the regular backbone flexibility, indicating that less aggregation does occur as previously discussed. From examination of the R g of aggregates of various sizes (Fig. ) it can also be seen that when larger aggregates did form with the flexible backbone, they were generally more compact (lower R g ) than their regular-flexibility counterparts. Overall, the more rapid single-chain collapse of the flexible polymer appears to lead to a stronger preference for intrachain aggregation compared with the regular-flexibility chain. This has the combined effect of reducing the number of aggregates, due to a lower probability of collisions between the more compact aggregates, and giving slightly more compact aggregates where aggregation does occur. Similar behaviour could likely be obtained in a more dilute system of stiffer chains, which, although indicates the RMS radius of gyration for single regular-exibility chains in the "good" solvent, calculated as described in Fig. . Results for exible chains in the poor solvent at two concentrations that are expected to be lower than c † (2 and 6 g/L) are also presented (dotted and dashed red lines).