TABLE OF CONTENTS A few formulations are considered here to see how the various chemicals that were studied in the previous sections function when combined in a product. Of all the chemicals we find in modern everyday formulations surfactants are by far the most widely used because of their amazing versatility.
One familiar group of products is the personal care range and this is taken as the starting point. Our familiarity is not confined to our intimate contact with personal care preparations but extends to the frequency with which we use them. A typical shampoo is considered here and we are given a head start in the form of a list of ingredients on the back label of the bottle.
In the formulations studied here and in subsequent sections amounts are given as percentage weight/weight (%w/w) as is now common.
The following details were taken from the label of a supermarket brand of shampoo. On its label is a list of the ingredients in terms of the CTFA or INCI names as is required for personal care products. The ingredients shown below make up what is a fairly complex chemical system and to understand the chemistry it is necessary to consider the ingredients and how they interact.
| Ingredient | Chemical names |
|---|---|
| Aqua | Water |
| Sodium laureth sulfate | Sodium lauryl ether sulfate, anionic surfactant |
| Sodium chloride | Sodium chloride, common salt |
| Cocoamide DEA | Coconut diethanolamide, non-ionic surfactant |
| Coco amido propyl betaine | Coconut amphoteric surfactant |
| Parfum | Fragrance |
| Citric acid | Citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid) |
| Polyquaternium | Quaternary cationic... |
