Figure 1. Conformation of a polymer in mixed cosolvents and system size effect.

Radius of gyration R_g as a function of cosolvent molar concentration x_c. The sizes of solvent s and cosolvent c components are chosen as 0.5σ and the interaction well depth between polymer p and c is taken as ε_pc=1.0ε. (a) shows results for chain length N_l=30. For comparison, we include data from the semi-grand canonical multi-scale simulations with all-atom details17. We also include experimental data obtained from the degree of volume swelling ratio q for PNIPAm6 and PAPOMe18. For representative purposes, the data from the multi-scale simulations and PAPOMe are shifted. The arrows indicate the corresponding y axis. (b) shows R_g/R_g(x_c=0) as a function of x_c for two different chain lengths N_l. In both parts, the error bars are the s.d. calculated from six independent simulations. The lines are drawn to guide the eye.