Ionic effects on the mechanical and swelling properties of a poly(acrylic acid/acrylamide) double crosslinking hydrogel

A P(AA/AM)–Fe(NO₃)₃ double crosslinking gel showed a superior tensile strength of 1471 kPa compared to those of all other metal salts tested, which was demonstrated by molecular simulation to result from the stronger hydrogen bonding in this metal–(COO)_n complex.