Effect of shampoo containing sodium carbonate on removing silicone oil

Almost all hair cosmetics contain silicone oil, and while it has a positive effect of giving hair a smooth shine, it can also be a hindrance to permed and colored hair. Moreover, silicone oil cannot be removed with regular shampoo. In this study, a shampoo containing sodium carbonate was developed to solve the problems caused by silicone oil deposited on hair, and its efficacy was verified. To verify the effectiveness of the shampoo, virgin hair was collected and bleached once. Afterwards, commercially available hair oil was applied to the bleached hair to produce sample hair. The sample hair was washed 1, 3, and 5 times with a commercially available shampoo and the developed shampoo. To verify the effectiveness of the developed shampoo, the concentration of silicone oils cyclopentasiloxane (CPS) and dimethicone (DMC) remaining in the hair were measured. CPS was analyzed using gas chromatography-mass spectrometry (GC-MS), and DMC was analyzed gravimetrically. The research results were as follows. When washed three times with the developed shampoo, the CPS removal rate was higher than when washed five times with a commercially available shampoo. Most of the DMC deposited on the hair could be removed by washing it three times with the developed shampoo. Therefore, it was proven that the pretreatment shampoo developed in this study was effective in removing silicone oil deposited on hair. However, since the pretreatment shampoo manufactured in this study has a somewhat high alkalinity, it is necessary to perform additional hair treatment after using the developed shampoo.