How does Biosilk keep your hair smooth - Household Chemistry - Why Is Milk White?: & 200 Other Curious Chemistry Questions (2013)

Why Is Milk White?: & 200 Other Curious Chemistry Questions (2013)

3. Household Chemistry

How does Biosilk keep your hair smooth?

Silicones. Although that particular brand name includes shampoos and hairsprays, only conditioners and detanglers are talked about in this section. To allow wet hair strands to easily slide past one another, conditioners and detanglers use two strategies.

First, they have ingredients that make the tiny scales on the hair shaft lie down, so they don’t have rough surfaces that grip other hair shafts. Citric acid is sometimes used for this purpose.

Second, they coat the hair shaft with slippery oils and silicones to make the hair shafts glide across one another easily during combing and brushing.

In Biosilk, cyclomethicone and dimethicone are the slippery silicone oils that help the strands untangle.


These are often used in other products as carrier fluids in hairsprays or as skin protectants to act as a moisture barrier and prevent chafing.


Conditioners that you leave in the hair (instead of rinsing out) will contain mostly silicones and alcohol. To make the silicones feel less greasy, alkyl benzoates such as lauryl benzoate are used.

Alkyl benzoates are lubricants themselves and also serve as solvents to carry sunscreens, and they are emollients, keeping the skin from drying out. Alkyl benzoates are esters, compounds that result when an alcohol reacts with an acid, in this case a fatty acid from vegetable oil. The alcohol end (the hexagonal benzyl alcohol at the bottom of the drawing) modifies the fatty end, so that it can join together oils and silicones and also help retain the fragrance molecules.