Commerical hair dyes contain a number of chemicals that may be toxic and carcinogenic. A new study published in the journal Chem assessed the effectiveness of a non-toxic carbon-based hair dye called graphene oxide.
Hair color is determined by two types of melanin that provide pigmentation to hair follicles: eumelanin and phenomelanin. In general, if more eumelanin is present, hair color is darker. The degradation of melanin results in gray or white hair.
What are most commercial hair dyes made of?
Most hair dye products change hair color through a series of oxidative, dye-forming chemical reactions under basic conditions. Generally, ammonia or another alkaline compound is used to open up the cuticles on the hair surface. Then, amine or alcohol-based colorants penetrate inside the hair. An oxidant, such as hydrogen peroxide, is also included in the compound to bleach the natural melanin pigments and initiate the reaction to make the final dye compounds.
Many of the molecular ingredients in commercial hair dyes are toxic, and some may be carcinogenic. If these chemicals are absorbed through the skin or inhaled they could cause allergic reactions or more severe consequences. However, these chemicals may be unavoidable as treating the hair with weaker solutions limits the effectiveness of coloration and leads to only temporary color that will be removed in a few washes.
What is graphene oxide?
Because most individuals in the world have dark-colored hair, there is a great demand for dark hair dyes. Recently, carbon nanotubes have been claimed to dye hair black by forming a surface coating. Carbon-based dyes may avoid many issues that are associated with standard commercial dyes, as these materials have low toxicity and should persist through brushing and washing.
One potential carbon-based dye is graphene-based sheets, such as graphene oxide (GO). GO sheets are made by the chemical exfoliation of graphite powders. GO sheets have the ability to adhere to many types of surfaces and form a smooth coating.
Can graphine oxide be used to dye hair?
A new study published in the journal Chem assessed whether GO could be used to dye hair to darker colors. They found that they could create water-based formulations with GO to apply the dye to hair by spraying, brushing, and then drying. Importantly, their GO-containing solution did not contain any organic solvents or toxic ingredients.
Furthermore, they found that dying the hair with GO provided other advantages to comfort, such as improved antistatic performants and heat dissipation. The GO-based dye also resisted repetitive shampoo washing and reached the same performance requirements of commercial permanent hair dyes. Lastly, they also tested the coloration of the GO-dye by gradually darkening and patterning the hair to create gradient effects and were able to produce a number of different shades of hair.
Importantly, these results show that the toxic ingredients currently included in commercial hair dyes could be replaced, resulting in safer hair dying procedures. As GO-based hair dye is comparable to other products on the market, this could be an innovation that we see available for purchase in the near future.
Written by Neeti Vashi, BSc
Reference: Luo, C., Zhou, L., Chiou, K., & Huang, J. (2018). Multifunctional Graphene Hair Dye. Chem.