Ximenia asks..I read that cationic surfactants stick very close to the hair because of their charge. So they can’t be rinsed off with water. Which shampoo do I have to use to avoid a build up? Is a build up possible at all? Can I use soap for this, too?
The Left Brain responds:
“Cationic” is a chemist’s way of describing a surfactant that has a positive charge. Many, but not all, cationics have a chemical name that ends in an “-ium” (like Polyquaternium-7.) There are also anionic (negatively charged) and non-ionic (non-charged) surfactants.
How do cationics condition hair?
Damaged hair has a negative charge and opposites attract so cationics make good conditioners because they will stick to the damaged spots of hair. This charge interaction helps them deposit on hair during rinsing but the attraction is not like glue which would make them hard to remove. It’s more like the static electrical stickiness a balloon has after you rub it on a sweater. The attractive force is relatively easy to over come which means that washing with almost any regular shampoo will remove them. If you find that your regular shampoo feels like it’s leaving something behind, that’s because most shampoos these days have some conditioning agents built in. In that case, use a clarifying shampoo and you should be just fine.
By the way, as a rule of thumb you should avoid using soap on hair (especially if you have hard water) because the soap can react with the mineral ions to form a residue that leaves your hair feeling raspy and looking dull.
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