The interface strength is sensitive to the ionic strength of the solutions. As the
assembly is immersed in salt solution, the ions may migrate into the interface and
shield the electrostatic interaction. When the ionic strength or salt concentration
Fig. 18 (a) Photographs of tensile tests of assembled hydrogels with negative and positive charges.
(b) SEM image of the fracture surface of the assembly. The tensile strength values of the assemblies
with different (c) negative charges or NaMAA concentration and (d) positive charges or DMAEMA
concentrations. Adapted from Ref. [58] with permission. Copyright 2018 Royal Society of
Chemistry
Fig. 19 (a) Peel-off test and (b) representative peel-off force-displacement curves of hydrogels
with different formulations. Adapted from Ref. [58] with permission. Copyright 2018 Royal
Society of Chemistry
232
J. Fu
assembly is immersed in salt solution, the ions may migrate into the interface and
shield the electrostatic interaction. When the ionic strength or salt concentration
Fig. 18 (a) Photographs of tensile tests of assembled hydrogels with negative and positive charges.
(b) SEM image of the fracture surface of the assembly. The tensile strength values of the assemblies
with different (c) negative charges or NaMAA concentration and (d) positive charges or DMAEMA
concentrations. Adapted from Ref. [58] with permission. Copyright 2018 Royal Society of
Chemistry
Fig. 19 (a) Peel-off test and (b) representative peel-off force-displacement curves of hydrogels
with different formulations. Adapted from Ref. [58] with permission. Copyright 2018 Royal
Society of Chemistry
232
J. Fu