Monday, November 22, 2010


Chemistry of shampoos


People expect a lot from shampoos. Unfortunately, it is not easy to tell a good shampoo from a poor one. Cost, fragrance, and lots of foam is what most people look for in shampoo products. Lather and foam is of little importance , but they often get the most attention.

Foaming occurs when surfactant molecules gather around air instead of oil. The result is millions of tiny bubbles. Obviously, the air bubbles are using the surfactants that should be removing dirt and oil. We have all seen shampoo advertisements showing happy, beautiful people taking showers with their heads heaped high with mounds of lather. These images have taught the public to associate lather with cleansing ability.

The truth is, lots of foamy lather only means too much shampoo was used. Excess foam equals waste. Sebum and other oils quickly destroy foam. Ideally, the head should have just enough lather to lubricate the scalp and hair. This will help your fingers massage the shampoo more effectively into the hair.

Fragrances and foaming qualities are not good ways to evaluate shampoos. Examine the hair's condition after several uses. Is it flyaway, is it hard to comb, does it seem limp, do colors fade, is the hair dry or the scalp itchy?

Carefully choose the shampoo to use and recommend. The quality of your services and the success of your repeat business may depend on the decision of product choice


The major types of surfactants are:

Anionic (an-eye-ON-ick)

Cationic (kat-eye-ON-ick)

Nonionic (non-eye-ON-ick)

Amphoteric (am-fo-TERR-ick)

Identification and names are important in all professions but for chemists, they are especially useful. Chemists try to choose names that provide information about the chemical. For example, anionic and cationic surfactants both end with "ionic" for a reason. These surfactants are a special type of chemical called an ion. Salt bonds are important type of chemical bonds in the hair. Salt bonds give hair many important properties and affect most chemical treatments. Although the term salt bond is used frequently in cosmetology, it is incorrect. These chemical bonds are actually called ionic bonds, and they occur between ions. Ions and ionic bonds are really quite simple to understand. Ions are molecules that have small electrical charges. These charges are positive or negative. They repel or attract each other. Opposite charges attract and similar charges repel.

Table salt, sodium chloride, is an excellent example. Sodium forms positive ions and chlorine makes negative ions. The opposite charges attract each other and make table salt. These charges are identical to those found in batteries or static electricity, but on a much smaller scale. Individual ionic bonds are very weak, but millions of them in combination are quite strong. Surfactants with a negative charge are called anionic. A surfactant with a positive charge is cationic.


Anionic Surfactants (Negatively charged ion) Anionic surfactants are the most widely used detergents in the cosmetology profession. They are inexpensive, simple to prepare, and excellent cleaners. They also rinse easily from the hair. A major disadvantage is that they can be harsh and irritating to the scalp Frequently, other surfactants and ingredients are added to reduce skin irritation.


Cationic Surfactants (Positively charged ion) Cationic surfactants are rarely used in high concentrations in the cosmetology profession. Many types are dangerous to the eyes but are safe and useful in low amounts. Until recently, their positive charges prevented them from being mixed with negatively charged anionic surfactants. Newer types, however, eliminate this incompatibility.


Look at the label!!! Here is a guide to how gentle your shampoo is according to the surfactant used:

Ammonium Lauryl Sulfate - very, very, harsh

Ammonium Laureth Sulfate- very harsh but better than the above

Sodium Lauryl Sulfate- better than the above, but still a little harsh

Sodium Laureth Sulfate-gentle, great pick!

TEA lauryl Sulfate-good pick

TEA Laureth Sulfate-good pick

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