The two scientists, Robert Christie and Olivier Morel, note that hair dye already is a multibillion dollar international industry, poised for even greater expansion in the future due to the graying of a global population yearning to cling to a youthful appearance.
And the scientists say the progress towards this could possibly lie with nano-sized colorants as they are composed of pigments that are 1/5000th the width of human hair, allowing easier penetration, thus remaining trapped for longer, and producing a longer-lasting hair color effect.
Explosion of growth
“The explosive growth in nanotechnologies is certain to continue to attract the interest of hair color chemists, for example, to exploit the potential of photonics to make use of materials that manipulate light to create bright colors without using traditional coloring materials, as one way of addressing potential environmental and toxicological concerns,” notes the study.
The scientists are also developing substances that stimulate the genes to produce the melanin pigment that colors hair. It states these substances promise to produce a wider range of more natural-looking colors, from blond to dark brown and black.
The scientists also say other new technologies may stop graying of the hair or prevent its formation altogether.
Outdated approach to hair dye
The reason for the study is said to be that most permanent hair coloring technology, is based on a 150-year-old approach that uses p-phenylenediamine (PPD), a chemical that produces darker, browner shades when exposed to air.
Concern over the safety of PPD and other hair dye ingredients, and demand for more convenient hair dyeing methods, has fostered an upswing in research on new dyes and alternative hair coloring technologies.
The study is the conclusion of an analysis of almost 500 articles and patents on the chemistry of permanent hair dyeing, which foresees much more innovation in the years ahead, including longer lasting, more-natural-looking dyes and gene therapy to reverse the gray.
The study is entitled Current Trends in the Chemistry of Permanent Hair Dyeing and can be found here .