Background: The use of polymers in hair care products is widespread, and silicones in
particular, are extensively used in cosmetic formulations. In addition, plant oils can also be used
for hair treatment.
Objective: In the present work, oil-in-water (O/W) nanoemulsions were prepared to repair chemical
damage to human hair samples, to investigate the combined use of a silicone polyether copolymer
(surfactant) that has a branch composed of poly(ethylene oxide) in its chains, and two types of
plant oils: coconut and ojon oil.
Materials and Methods: Surfactant-oil-water formulations were obtained by ultrasonic processing.
The nanoemulsions were then applied to human hair strands previously damaged with sodium hydroxide,
to compare the treated strands with untreated ones. The efficacy of the formulations was
investigated by scanning electron microscopy, thermogravimetric analysis and mechanical tests.
Results and Discussion: Stables nanoemulsions were obtained with average size of the dispersed
droplets up to 400 nm. The micrographs suggest that the action mechanism of the nanoemulsions
depends not only on the type of plant oil used and on size of the droplets dispersed in the system,
but also on the type of hair that receives the treatment. The thermal analysis showed that the use of
nanoemulsion changed the temperature of keratin interconversion to higher values, which can
make hair fibers more resistant to heat. Hair resistance was improved when comparing virgin samples
to the damaged ones.
Conclusion: The nanoemulsions were efficient in the treatment of the hair samples, which showed
a significant improvement in their mechanical properties.