When I was a little kid, I desperately wanted to have black hair. My natural hair color is already a pretty dark brown, but I always loved the look of the long black hair my mother used to have when she was young. Of course, my mother never allowed me to dye my hair even in an effort to be more like her—and for good reason. Traditional hair dyes require expensive treatments that often damage the structure of your hair irreparably. But thanks to a paper published by the Huang Lab at Northwestern, a future of damage-free hair dye technology may not be far off.
A paper entitled “Multifunctional Graphene Hair Dye” was released today by Chem, a new journal from Cell Press. In it, the researchers describe a new dye formulation using reduced graphene oxide (rGO) that can turn blonde hair a lasting black. rGO is a large, flat molecule composed primarily of carbon. You get it through a series of reactions with graphite, the material you find in pencil lead. That is really cool because molecules like graphene are mostly used in fields like semiconductor technology and surface chemistry. Graphene and rGO look nothing like the small molecules that are most commonly used as colorants for hair dyes.
And unlike traditional hair dye treatments that structurally alter hair strands to achieve permanent color, rGO coats the hair strand with the help of a molecule called chitosan. Chitosan is composed of repeating units of sugar molecules. With the addition of ascorbic acid, more commonly known as vitamin C, the chitosan will bind like glue to both the rGO and keratin proteins in the hair strand. This can be done by either spraying the rGO/chitosan/vitC mixture directly onto hair or combing it through. Then you dry it, either in air or with a blow dryer, for approximately 10 minutes. What you are left with is black, lustrous hair.
So how does this rGO compare to hair dyes that are already on the market? First, the concentration of rGO solution affects how dark the hair becomes. If you are dying blonde hair for example, you can get colors anywhere between light brown to full black depending on how much rGO is added to the formulation. That means this one dye could replace a whole shelf of shade variations that you would otherwise have to buy separately.
Second, the rGO/chitosan dyed hair survived 30 shampoo washes with little to no degradation in color. That’s because chitosan is only water-soluble in the presence of vitamin C. When the vitamin C is removed through the drying process, the chitosan binds so tightly to the hair surface that the rGO can’t be washed out easily, even with shampoo. The means that rGO/chitosan has just as much, if not more, staying power than dyes already on the market.
Finally, rGO/chitosan is actually better than most hair dyes because of its antistatic properties. Hair dyed with rGO/chitosan is more resistant to pesky fly-aways after treatment than untreated hair. That means your hair do will stay put longer throughout the day.
All in all, these researchers did a great job of bridging material science with everyday aesthetic design. This technology is still far away from being marketed to the public and there was not mention as to how expensive such a product would be. But still, I have hope that someday I will be able to buy graphene-based hair dyes at a Walgreens near me. Maybe even my mother will approve.
Find the original article here.