초록 |
The need for hair dyeing has recently been intensified because of the ever-increasing occurrence of gray hair at the early age. Herein, we report a natural formulation for black hair-dyeing, which does not require toxic chemicals and harmful oxidizing agents, inspired by the ancient iron gall ink. The Fe2+ cations bound to tannins are oxidized rapidly upon their exposure to the air and form the blackish Fe3+-tannin supramolecular complex that coats hair firmly. After dyeing, the dyed black color does not fade under sunlight exposure for at least three months and also after shampooing. Considering the long-term stability and simple process, this natural formation for black hair-dyeing would have merit in the cosmetic industry. |