Table 2 Summary of recent self-healing systems based on supramolecular hydrogen bonds and metal-coordination crosslinking: mechanical characteristics, self-healing-conditions and efficiencies

MG-SHPU

− 4.45

H-bonding, NIR radiation, and modulus of toughness, 40%

0.75 wt% MG (MG075) gave maximum healing efficiency up to 40%. Intermolecular diffusion of SHPU which was accelerated by thermal energy generated by NIR absorptions

[106]

RGO-HPUs

NA

H-bonding, MW energy and app. 100%

Composite is also incorporated with iron oxide/TiO₂. This combined composites exhibited an excellent shape memory, self-healing and self-cleaning properties

[107]

H-bonding, direct sunlight and NA

G-PAM-PAA

NA

H-bonding, thermal healing and app. 100%

Above 10 wt% of graphene yields the self-healing behavior

[84]

GO-HBN

− 5 to 9

H-bonding, RT, ~ 60%

Protecting barrier for electronic wires and devices, sealing layer for gas systems

[102]

FG-TPU

~20–30

H-bonding, IR and MW radiation, and ~ 98%

FG-TPU composites exhibit improved mechanical properties and could be healed effectively and rapidly by IR, electricity, and electromagnetic wave

[84]

µNi-M-NH₂

− 20 to 10

H-bonding, RT, 15 min, ~ 90%,

Addition of nanostructured µNi particles with nano-structured surfaces significantly enhances the mechanical properties

[108]

BNNSs-supramolecules

− 7 to 43

H-bonding, ~ 100%, 85 °C, 30 min

Polymer nanocomposite with 8 vol% BNNSs exhibits two orders of magnitude improvement in electrical resistivity over that of the pristine polymer network

[109]

UPy-K-UPy/CNC-UPy

− 50

H-bonding, UV-light, 20–80 s, ~ 100%

H-bonded UPy supramolecular polymer and CNCs decorated with the same supramolecular motif show an attractive combination of high stiffness, high strength, and rapid and efficient optical healing

[75]

Si-GO-HPU

− 50 to − 51

H-bonding, UV-MW, 4–6 min ~ 100%

The surfaces of the HPU/Si-GO nanocomposites also displayed inherent hydrophobicity without any additional surface modification

[110]

CNT-PU

NA

Coordination bond, NIR-light, 90 °C, 1 h, ~ 93%

Zn²⁺ coordinated metallo-supramolecular CNT-PU nanocomposite that showed a strong, tough, and elastic mechanical properties and was able to self-heal multiple times

[89]

V₂O₅-PDMS-g-PUR

− 12.5 to − 53.1

H-bonding, 50 °C, 120 min, 85.4%

V₂O₅ nanofibers enhances the mechanical properties and healing efficiency of the PDMS-g-PUR through a reversible hydrogen bonding mechanism

[111]

GO-PDMAA

NA

H-bonding, NIR radiation, 3 min, 96%

Self-healable GO-clay-PDMAA hybrid hydrogels with high extensibility and mechanical strength contributed by both hectorite clay and GO as cross-linking agents

[112]

GO-PAA

NA

H-bonding, NIR radiation, 30 °C, 24 h, ~ 100%

The strong interactions between the PAA chains and the GO sheets are essential to the mechanical strengths of the healed gels

[113]

GO-PAACA

Coordination bond and H-bonding, Ph7, 10 min, ~ 100%

The polar groups of the PAACA side chains and oxygen-containing groups of GO nanosheets via coordination interactions

[114]

HPU-SRGO

NA

H-bonding, 50-60 s in MW, 1–3 min in sunlight, ~ 96.8%

Shape memory of HPU and energy absorbing capability of SRGO-assisted melting, diffusion, and rearrangement of the soft segment of HPU to crack place

[115]