Table 1.

Unfolding free-energy and the corresponding force (in piconewtons) for stretching a polystyrene ($\mathrm{\Delta }G$ in kilocalories per mole) from a collapsed configuration of end-to-end distance $L_c$ (in Ångstroms) to an extended configuration of length $L_e$ (chosen based on the onset of elastic region) (in Ångstroms)

System	$L_c$	$L_e$	$\mathrm{\Delta }L$	$\mathrm{\Delta }G$	F=$\mathrm{\Delta }G$/$\mathrm{\Delta }L$
PS20
Water	10.8	39.3	28.5	5.2	12.7
TMAO	5.7	39.3	33.6	7.5	15.5
Urea	12.7	39.3	26.6	4.4	11.4
PS40
Water	6.2	86.1	79.9	25.8	22.4
TMAO	9.3	86.1	76.8	27.2	24.6
Urea	14.3	86.1	71.8	14.1	13.6