Emulsions are widely used in our daily lives including foods, pharmaceuticals and fast moving consumer goods (FMCG). Researchers from Institute of Process Engineering, Chinese Academy of Sciences (IPE) prepared uniform-sized silicone oil microemulsions by the method of emulsification. The stability and deposition on hair surface of these microemulsions were investigated.

The prepared silicone oil microemulsions with different diameters of 3.7, 15.5, 22.7 and 40.0μm were added into model shampoos and conditioners to observe micrograph, measure the mean droplet size, droplet size distributions and silicone oil deposition on hair. Effects of size and uniformity on silicone oil deposition, influence of silicone oil deposition on surface morphology and friction of hair were all discussed in the work.

According to the results, the microemulsions with uniform-sized silicone oil droplets of 22.7μm had the most stability. The droplet size and uniformity greatly affected the deposition of silicone oil on hair. Droplets of smaller and uniform size enhanced the deposition, supported by SEM and AFM results.

This work was supported by Unilever Research Colworth (UK) and National Natural Science Foundation of China. The results of this research have been published on the Journal of Colloid and Interface Science.