Facile Access to Guar Gum Based Supramolecular Hydrogels with Rapid Self-Healing Ability and Multistimuli Responsive Gel-Sol Transitions.

In this work, we prepare guar gum-based supramolecular hydrogel through the formation of borate/didiol bonds. This dynamic and reversible noncovalent borate/didiol interaction is critical for the multifunctional properties of supramolecular hydrogel. The FT-IR and XRD analysis verified the existence of boronate ester interactions between borax and guar gum. Moreover, the viscoelastic and mechanical behaviors of the hydrogels with different guar gum concentrations showed that the storage modulus and compressive stress were highest at guar gum concentration of 2 wt %. Besides, due to the dynamic and reservable properties of boronate ester, these guar gum-based hydrogels had excellent self-healing property, outstanding reformable and injectable capability. In addition, hydrogels also exhibited reversible gel-sol transformations by the application of physicochemical stimuli such as thermal and pH value. The coupling of these multifunctional properties made from low-cost, environment friendly, and readily available materials could have potential applications in many biomedical areas in the future. We expect that this simple strategy of fabricating the self-healing guar gum hydrogels with multistimuli responsive properties may enrich the avenue in the exploration of multifunctional guar gum based hydrogels to expand their potential applications in various fields.