Although most permanent hair dyes used today are harmful to our hair, colour dyes are still continually being used by both men and women. “Your hair is covered in these cuticle scales like the scales of a fish, and people have to use ammonia or organic amines to lift the scales and allow dye molecules to get inside a lot quicker,” says senior author Jiaxing Huang, a materials scientist at Northwestern University. But lifting the cuticle makes the strands of the hair more brittle, and the damage is only exacerbated by the hydrogen peroxide that is used to trigger the reaction that synthesises the dye once the pigment molecules are inside the hair. Could these problems be solved by Graphene dye?
Altering Your Hair Colour With Graphene
Today I learnt four things about Graphene-based Hair Dye. It can be applied by spraying, brushing, and then drying. Graphene hair dyes do not contain organic solvents or toxic molecular ingredients. The naturally black material is not only durable, but it can also reach the performance of permanent hair dyes.
Coating rather than penetrating the hair, the effectiveness of Graphene has to do with its structure, which is made of up thin, flexible sheets that can adapt to uneven surfaces. “Imagine a piece of paper. A business card is very rigid and doesn’t flex by itself. But if you take a much bigger sheet of newspaper–if you still can find one nowadays–it can bend easily. This makes graphene sheets a good coating material,” said Huang. With his team, they coated samples of human hair with a solution of graphene sheets, and were able to turn platinum blond hair black and keep it that way for at (least) 30 washes -the number necessary for a hair dye to be considered “permanent.”
The experiment managed to prove that Graphene sheets are particularly good at keeping out water during washes, which keeps the water from eroding both the graphene and the polymer binder that the team also added to the dye solution to help with adhesion. The graphene dye has other additional advantages. Each coated hair is like a little wire in that it can conduct heat and electricity. This means that it’s easy for graphene-dyed hair to dissipate static electricity, eliminating the problem of flyaways on dry winter days. The graphene flakes are large enough that they won’t absorb through the skin like other dye molecules. And although graphene is typically black, its precursor, graphene oxide, is light brown. But the colour of graphene oxide can be gradually darkened with heat or chemical reactions, meaning that this dye could be used for a variety of shades or even for an ombre effect.
The next step for Huang is making it happen. He hopes to do this by getting so he can continue his research and make these dyes a reality. “This is an idea that was inspired by curiosity. It was very fun to do, but it didn’t sound tremendous and noble when we started working on it,” he says. “But after we deep-dived into studying hair dyes, we realised that, wow, this is not at all a small problem. And it’s one that graphene could help to solve.”