. 2021 Mar 5;15(3):5341–5354. doi: 10.1021/acsnano.0c10893

Table 1. pH and Storage Modulus of WPI Solution with and without the Presence of Metal Ions (120 mM) after 24 h Incubation at 90 °C^a.

samples	ref	K⁺	Na⁺	Mg²⁺	Ni²⁺	Co²⁺	Al³⁺	Fe^2/3+	Zr⁴⁺	Sn⁴⁺
radius (pm)	–	152	116	86	83	88	67	92/78	86	83
pK_a	–	14.5	14.2	11.4	9.9	9.6	5	9.5/2.2	–0.3	–0.6
pH	3.0	2.9	2.8	2.8	2.8	2.7	2.5	1.4	0.8	0.7
storage modulus (Pa)	0.5	21	24	182	425	155	164	–	462	0.3

Note: The values for the radius and electronegativity were taken from refs (43−45). Storage moduli of the PNF solution/hydrogel (in the liquid state)⁴⁶ were extracted at 1.0 Hz from the results of the frequency sweep.

Table 1. pH and Storage Modulus of WPI Solution with and without the Presence of Metal Ions (120 mM) after 24 h Incubation at 90 °Ca.

Table 1. pH and Storage Modulus of WPI Solution with and without the Presence of Metal Ions (120 mM) after 24 h Incubation at 90 °C^a.