Cellulose nanocrystal dye as reinforcement matrix of lipstick for inhibiting color migration

Lipstick is a kind of popular cosmetic, which can give the lip a beautiful color and improve its appearance. The problem is that dye molecules would be in contact with the skin, whereas the lipstick made with dyed CNCs (CNC-lipstick) would reduce the contact. Herein, we demonstrated that the deficiency of color migration can be overcome by using the cellulose nanocrystal (CNC) dye to replace conventional dye in the lipstick substrates. The lipstick containing CNC dye (CNC-lipstick) could effectively inhibit the color migration and was easily erased as compared to ordinary lipsticks. The color change on the scoured skin was as high as Delta E* = 30.4 after using red ordinary dye-lipstick for 8 h, and red residue was clearly observed in the texture of the skin. Further cleaned with makeup remover, the color change on the scoured skin was Delta E* = 6.4. Notably, the color change of CNC-lipstick was Delta E* < 5, and only a small amount of red residue could be observed in the texture of the skin. The reduction of color migration from the lipstick to the skin was probably due to the fact that the dye absorbed by the CNC, which slowed down the diffusion rate of dye molecules. Our work paves the way for using CNC dye for inhibiting color migration in the lipstick application. [GRAPHICS] .