Table 2.

Hydrogel potential^a

Gel	[KCl]b	Sc	${\varphi }_s^0$/Vd	${\varphi }_g{|}_{x=+\infty }$/Vd	${\varphi }_s^{0T}$/Ve	${\varphi }_g{|}_{x=+\infty }^T$/Ve
G-0.0001	0.0001	20.80	−0.062	−0.076	−0.059	−0.076
G-0.001	0.001	10.29	−0.025	−0.039	−0.017	−0.028
G-0.01	0.01	8.00	−0.016	−0.018	−0.001	−0.001

^a The underlined data is used for the computation of K_D in the Section 3.1.2

^b KCl concentration of bathing solution of hydrogel

^c swelling ratio of gel

^d experimental surface potential (${\varphi }_s^0$) and center potential (${\varphi }_g{|}_{x=+\infty }$)

^e computational surface potential (${\varphi }_s^{0T}$) and center potential (${\varphi }_g{|}_{x=+\infty }^T$) obtained using the Donnan theory