Issue 5/2018 - Breakthrough in graphene self-healing coating research

A few days ago, a research team at Harbin Institute of Technology combined graphene oxide and soft, self-healing polymers to design a coating reminiscent of the self-healing function of the human epidermis, which has the strength of tooth enamel and can be used in
architectural coatings and biomedical equipment coatings.

The new material is hardened by graphene oxide on the outside and hydrogen-bonded dynamic structure formed by tannins (tannic acid) and polyvinyl alcohol (PVA) on the inside, which is similar to the structure of skin epidermal cells, and performs its duties inside and outside to meet the characteristics of
abrasion resistance and flexibility.
By combining the epidermal layered structure with the mechanical properties and barrier properties of graphene oxide, this study overcomes the fundamental dilemma
of realizing hard materials with self-healing ability.
A quasilinear layer-by-layer (LBL) film composed of graphene oxides is deposited on top of the multilayer polymer as a protective hard layer, forming a layered state
that mimics the structure of the epidermis.
This hybrid multilayer structure is completely self-healing after damage: the soft lower layer provides additional polymer to help restore
the outer hard layer.
The coating shows the potential market application direction that can protect both mobile phone screens and buildings, and its bactericidal properties can also make it valuable in the protection of biomedical devices
.