Hard Material With Self-Healing Capability

Imagine a cellphone that can heal from cuts and scratches just like the human body can. For Chinese researcher Ming Yang and his team at the Harbin Institute of Technology, it’s not really a question of imagining anymore: They have developed a new kind of smart coating that manages to be both soft and hard, not unlike our own skin.

We designed a self-healing coating with a hardness that even approaches tooth enamel by mimicking the structure of epidermis,” Yang says. “This is the most desirable property combination in the current self-healing materials and coatings.”

As described in a paper published Wednesday in ACS Nano, this new material is far from the first smart coating, with previous research looking at both soft and hard coating options. Yang says there’s serious global need for better self-healing materials.

Nowadays people always talk about environment and energy,” he adds. “A self-healing material can help save a lot of money and energy using a smart, environmental friendly way. But the current self-healing materials and coatings are typically soft and wear out quickly. This can bring potential problems about the management of plastic waste.

This new material could solve those waste problems, as it comes closer than any predecessor to combining the flexibility of a soft coating and the resilience of a hard coating, without the short lifespan of the former or the brittleness of the latter. This could be the best of both worlds.

The trick is to use artificial materials in nature’s way,” explains Yang. “The multilayer structure is the key. By placing a hard layer containing graphene oxide on top of a soft layer, we create a smart hybridization you can get the most out of.”

The graphene oxide material used in the coating’s top layer is harder than skin cells, offering a toughness closer to that of teeth enamel. The amazing thing, according to Yang, is that the coating’s hard and soft layers are able to work together to create healing properties that neither could accomplish on its own.

Source: https://pubs.acs.org/