The folding time was found to be 0.5-1 µs for flexible chains and 1.7-9 µs for regular chains (Table ). The slower chain collapse for stiffer chains is consistent with previous reports on the collapse dynamics of single semiflexible chain as a function of flexibility. In terms of the dependence of the kinetics of chain collapse on molecular weight (chain length), scaling of the folding rate with N 1/3 has been previously reported, and the behaviour of the single chains in this work is consistent with this scaling (ESI Fig. ).