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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Thanks, BB, for your usual succinct clarification. Is there a word for the fear of chemistry that seems to be pervading the personal care marketplace? Why would someone choose the build-up of soap scum over the conditioning effects of cationic conditioning ingredients?
I might add is that the cationic character of quaternized conditioning agents allows them work with an ultra thin coating of the hairshaft, hence less weighing down of the hair than conditioning with emollients or fatty alcohols. Also, cationics offer anti-static property to the hair. What’s not to like about these benefits?
@Barbara: Misplaced “Chemo-phobia” does seem rampant right now!
I’m confused, when you say, “By the way, as a rule of thumb you should avoid using soap on hair” are you talking about surfactants or do you mean bar soap?
I’m talking about bar soap. Surfactants are fine for hair.
I read this: ”
Buildup that causes dull, dry or tangle-prone hair and resists removal with conventional shampoo is not silicone buildup. Anionic-cationic complexes are the true culprits behind most buildup.
Removal-resistant buildup occurs as a result of interactions between anionic (negatively charged) surfactants and common cationic (positively charged) conditioning ingredients. Both cationic surfactants and cationic polymers have been shown to form removal-resistant complexes with anionic surfactants. These complexes are extremely resistant to removal and exhibit high potential for buildup. One experiment showed that washing monofunctional cationic surfactants like cetrimonium chloride from hair with normal alkyl sulfates or alcohol ether sulfates does not remove all the cationic from the hair, and, in addition, the anionic detergent can build up with the cationic (Chemical and Physical Behavior of Human Hair). ”
in a blog on a long hair forum and have since switched to a shampoo without “-ium” ingredients. Am I now missing out the benefits of the cationics? My conditioner does satisfactory every wash.
Personally, I think it’s downright silly to indict a whole category of ingredients, quats, because of the fear of build-up. Quats are not the only cationic ingredients in hair-care products. The whole idea of conditioning ingredients is to be substantive to the hair, to stick. Cationic conditioning ingredients, including quats simply stick to the hair by electrostatic, ionic, force as opposed to other forms of stickiness. In the beginning, we had other sticky ingredients, such as waxes and oils, which were much heavier on the hair and could also build up. Quaternization allows for very light-weight films to form on the hair shaft. They also are chemically suited for polymerization, which enables cosmetic chemists to develop conditioning ingredients that have improved features, such as heat protection and color retention. The blogging chemophobes want to take us back to the Dark Ages. Have you ever looked closely at cave man hair? I rest my case!