Structure optimization of self-healing hydrogels formed via hydrophobic interactions

Supramolecular Polymer Networks: Preparation, Properties, and Potential

“…Static light scattering reveals that these hydrogels are more homogeneous than the corresponding gels prepared by a chemical crosslinker, which is attributable to the mobility of the cross-linking nodes. Large hydrophobic monomers such as stearyl methacrylate (C18) and dococyl acrylate (C22) with very low water solubility could also be copolymerized with acrylamide in a micellar solution by the addition of salt (NaCl) [26,262,263]. The salt leads to micellar growth and solubilization of the hydrophobes.…”

The self‐healing mechanism of an industrial acrylic elastomer

“…The material is very tough as its toughness is 1.91 MJ/m 3 , which is almost twice of the value (1 MJ/m 3 ) that was obtained for the copolymer of acrylamide and acrylate. 17 The healing efficiency of the material is determined by the ratio of the toughness of the healed sample to that of the original sample. 22 Figure 2(b) shows that the self-healing efficiency increased with healing time and reached an average value of 60% after a healing time of 240 min.…”

“…12 The self-healing ability of these materials is attributed to the reversible noncovalent interactions in particular such as hydrogen bonding, 6,8,[13][14][15] hydrophobic association, [16][17][18][19][20] ionic bonds, [21][22][23][24] and p-p stacks. 25,26 However, the low mechanical strength has limited the practical application of these materials.…”

Self-Healing Hydrogels Formed via Hydrophobic Interactions

“…Physical hydrogels derived from hydrophobically modified hydrophilic polymers drew much less interest in the past, but they have recently attracted intense attention because of their extraordinary properties [4,8,[31][32][33][34][35][36][37][38][39][40][41][42]. To produce mechanically strong hydrogels via micellar copolymerization, blocks of hydrophobes with long alkyl side chains such as n-octadecyl acrylate (C18A) or dococyl acrylate (C22A) should be incorporated into the hydrophilic backbone [32,34]. However, although hydrophobes with an alkyl-chain length of up to 12 carbon atoms can easily be copolymerized with hydrophilic monomers, larger hydrophobes cannot be copolymerized in micellar solutions.…”

“…To solve this challenge, salts such as NaCl or NaBr were added to the micellar solution [32]; this weakened electrostatic interactions and caused the micelles to grow [63][64][65][66][67], which, in turn, provided solubilization of large amounts of hydrophobes in the micellar solution. Figure 3a, b demonstrates the NaCl-induced solubilization of C18A in an aqueous 22 % (w/v) SDS solution [34,38]. The hydrodynamic correlation length of the solution, ξ H (Fig.…”