Salt-inactive hydrophobic association hydrogels with fatigue resistant and self-healing properties

Traditional hydrophobic association (HA) hydrogels can obtain excellent mechanical properties in the presence of anionic surfactants. However, such surfactants are sensitive to salt solutions, resulting in large fluctuation of mechanical properties for hydrogels. Here, a combined surfactant consisting of anionic surfactants (sodium dodecyl sulfate, SDS) and amphoteric surfactants (dodecyl dimethyl betaine, BS-12) was successfully introduced into HA hydrogels as stable physical crosslinking points. The resulting SDS/BS-12-HA hydrogels exhibited high tensile stress up to about 700 kPa. Moreover, the hydrogels demonstrated salt-inactive, self-healing and fatigue resistance properties owing to their unique dynamic and reversible physical crosslinking structure. Therefore, it's envisioned that this work may open a new method to develop a soft salt-inactive material with stable and excellent mechanical properties for extending the application range of hydrogels. (C) 2018 Elsevier Ltd. All rights reserved.