Self-healing materials have attracted much attention because that they possess the ability to increase the lifetime of materials and reduce the total cost of systems during the process of long-term use; incorporation of functional material enlarges their applications. Graphene, as a promising additive, has received great attention due to its large specific surface area, ultrahigh conductivity, strong antioxidant characteristics, thermal stability, high thermal conductivity, and good mechanical properties. In this brief review, graphene-containing polymer composites with self-healing properties are summarized including their preparations, self-healing conditions, properties, and applications. In addition, future perspectives of graphene/polymer composites are briefly discussed.

The modified MWCNT covalently bound with polymers avoids aggregation and reinforces the mechanical performance of the composite.

Polymer hydrogels have attracted much attention due to their mechanical, biological, and physicochemical properties. Incorporation of functional material enlarges their applications. Graphene, as a promising additive, has received great attention due to its large specific surface area, ultrahigh conductivity, strong antioxidant, thermal stability, high thermal conductivity, and good mechanical properties. In this brief review, graphene‐containing polymer hydrogels with special properties are summarized including their preparations, properties, and applications. In addition, future perspectives of polymer hydrogels containing graphene are briefly discussed.

Self-healing materials can prolong device life, but their relatively weak mechanical strength limits their applications. Introducing tunable metal-ligand interactions into self-healing systems can improve their mechanical strength. However, applying this concept to solid elastomers is a challenge. To address this need, polyurethane-containing metal complexes were fabricated by introduction of a pyridine-containing ligand into polyurethane, and subsequent coordination with Fe 2 + . The strong reversible coordination bond provides mechanical strength and self-healing ability. By optimizing the monomer ratio and Fe 2 + content, the resulting complex possesses a very high tensile strength of 4.6 MPa at strain of around 498 % and a high Young's modulus (3.2 MPa). Importantly, the metal complex exhibits an extremely high self-healing efficiency of approximately 96 % of tensile strength at room temperature and around 30 % at 5°C. The complex is notch-insensitive and the fracture energy is 76186 J/m 2 , which is among the highest reported values for self-healing systems. specimens were stretched until the notch turned into a running crack to determine the critical length (Lc). Fracture energy was determined as Γ = W Lc ð Þ a0 b0 , where Γ represents the fracture energy, a 0 represents the sample width, b 0 represents the sample thickness. 4 5 6 7 8

A novel polyampholyte gel electrolyte with high ionic conductivity and high mechanical strength was developed and was suitable for supercapacitors.