Researchers from Northwestern University have developed a hair dye based on graphene oxide that "does not include toxic compounds commonly used in hair dyes". As an added bonus, graphene-colored hair enjoys much less electrostatic frizz. Due to graphene’s thermal conductivity, the dye may even help dissipate heat on hot days. The team has filed a provisional patent for the color.
The researchers "used the biopolymer chitosan and ascorbic acid (vitamin C) to disperse flakes of graphene oxide (GO)—and the darker derivative, reduced GO—in water," which reportedly formed a smooth coating on the hair surface.
The researchers showed that the dye works quickly and can be applied by spraying or brushing. It also binds tightly to hair and resists fading for at least 30 washings. The researchers attribute the tight binding to several factors including graphene’s thinness, which helps it conform to uneven surfaces; hydrogen bonding between graphene and chitosan; and chitosan’s ability to bind tightly to keratin, a protein on the surface of hair.