Self-healing capability is one of the trademarks of living tissues
including plants and human bodies. It is extremely desirable to render
man-made materials, including coatings, this capability, for the sake
of prolonging the material lifetime and minimizing maintenance.
There has been some recent success in preparing self-healing polymer
materials, such as the autonomic healing via microencapsulated
liquid healing agent and externally triggered repairing on the basis of
thermally reversible Diels-Alder (DA) reaction or light-induced thiolene-
based reaction; a common feature for these systems is that
covalent bonds are reestablished (i.e., “chemical recovery”) to heal
damages.
We are developing an autonomic “physical” recovery for a
particular surface property of a material: low surface energy. We have
successfully employed the surface segregation strategy to prepare
low surface-energy, cross-linked films with fluorine-rich surfaces that
are water/oil repellent, in which the addition of a small amount (1
wt%) of fluorine can lower the surface energy of the coating to as low
as 10 mN/m. However, it has been shown that the fluorine-rich layer
is generally very thin (< 20 nm), and the coating may not sustain the
low surface-energy character upon mechanical abrasion. We have
developed a self-replenishing strategy to sustain the low surfaceenergy
character: in case of surface damage that leads to the loss of
the top layers of the coating, fluorinated tails from sub-layers will be
able to reorient themselves to minimize the air/film interfacial energy
of the newly created surface. We will demonstrate how the selfreplenishing
of fluorinated species takes place and discuss a variety
