When our body suffers an injury, in many cases the damage is
autonomously repaired and full recovery of the materials’ properties takes place. Several approaches for introducing this selfhealing concept in synthetic materials have been explored in
recent years, and various reviews have been published on this
field.13
To date, the most successful examples are based on encapsulation and reversible chemistry, including both covalent and
noncovalent chemical bonds. The encapsulation approach48
is one of the most studied self-healing concepts and is based on
the introduction of microcapsules with a healing agent, which
polymerizes upon release from the microcapsules. The system
has a great potential for healing internally developed microcracks
but fails to repair a macroscopic cut in the material. Furthermore,
the irreversible nature of the healing mechanism is a limitation. A
method to overcome this last limitation is by making use of
reversible chemistry. Intermolecular interactions, such as hydrogen bonding913 and metalligand coordination,1416 have
been demonstrated to be especially useful to introduce the
capacity to heal a polymer multiple times. However, the dynamics of the network differ significantly from a covalently crosslinked material, since for example for hydrogen bonding the
bond strength is much weaker. Alternatively, in the case of
reversible chemistry based on strong covalent bonds, such as
thermoreversible DielsAlder reactions,17,18 the healing process
usually takes place at high temperatures. Therefore, weaker
covalent bonds, such as disulfide groups, can be beneficial to
introduce a healing functionality at lower temperatures, meanwhile keeping a reasonable level of bond strength