Most simulations used a friction coefficient of γ = 20 ps -1 , chosen to give a monomer diffusion coefficient consistent with that of the AA model in DCB (ESI Fig. ). With this friction coefficient, the maximum timestep that gave stable simulations was 8 fs, which was used in all CG simulations unless otherwise stated. A number of simulations were also conducted at lower friction to speed up equilibration as well as to examine the effect of viscosity on both single-chain folding and multi-chain aggregation. These simulations used γ = 2 ps -1 and a timestep of 5 fs. All simulations were conducted at constant volume and temperature.