Artificial development of smart materials from agricultural waste or food residues is particularly desirable for green chemistry. In this paper, dual-network self-healing hydrogels were successfully fabricated by using functional microcapsules. These microcapsules were established by biomass porous carbon (PC) after recycling of apple residues. Glutaraldehyde (GA) as the healing agent was embedded in the porous carbon, and the outer surface was coated with polydopamine (PDA). After the microcapsules were added, modifying guar gum-type hydrogels were successfully obtained with dual self-healing performance by the combination of a healing agent and metal-ligand coordination. The self-healing efficiency was about 89.9% from the tension test, and the fracture strength was measured as 7.68 MPa. These results not only highlight a new idea for the utilization of apple residues but also provide a new method for the preparation of excellent self-healing hydrogels.
Keywords: apple residues; microcapsules; polydopamine; porous carbon; self-healing hydrogels.