High Strength Hydrogels with Multiple Shape Memory Ability Based on Hydrophobic and Electrostatic Interaction

Hydrogels with multiple shape memory ability have aroused great interest due to their promising applying value in varied fields. Nevertheless, the weak mechanical performance of most shape memory hydrogels seriously impedes the practical application in more complex environments. Here, we report a novel hydrogel with both highly mechanical and multi-shape memory properties composed of stearyl methacrylate (SMA), acrylic acid (AA) and Quaternary chitosan (QCH). The electrostatic interactions between AA and QCH together with the hydrophobic interactions of alkyl chains in SMA endow the hydrogel with great stain-stress and fatigue resistance. Furthermore, due to the reversible destruction and construction of physical cross-links, the prepared hydrogels also exhibit shape memory ability in responsive to different stimuli such as temperature, pH and NaCl solution. And the multiple shape memory effect can be accomplished via programmable combination because of the relatively independent physical interactions in the hydrogels.