The coloration of hair is usually done with dyes that need harsh post treatments with products such as ammonia, so as to have durability. In this work, we have developed nanoparticles (medium range 200 nm), that can be fixed to fibres such as protein fibers (wool,silk and hair) and to polyamide fibres, by a process that does not need any after treatment. One advantage of using nanoparticles instead of dyes is that dyes can dye the scalp and therefore great care is necessary in the choice of these dyes. Synthetic dyes of colours such as red, orange and black, for example, are usually AZO dyes and some these dyes can split into amines (when in the presence of reducing agents present in the body)that are potencial carcinogens. Particles on the other hand do not dye the scalp and therefore present no such danger. At the moment, the dyeing with nanoparticles still does not have the same durability as dyes to washing, but our results with wool and polyamide fibers already show that a covalent bond can be formed between the nanoparticles and the amine groups, also present in the hair, improving greatly the durability to washing.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2009: Fabrication, Particles, Characterization, MEMS, Electronics and Photonics
Published: May 3, 2009
Pages: 102 - 105
Industry sector: Advanced Materials & Manufacturing
Topic: Nanoparticle Synthesis & Applications