A REVIEW OF AN ARTICLE APPEARING IN "EDUCATION IN CHEMISTRY".
By Rosemary Black.
I found the article very interesting. It highlighted the importance of chemistry in the cosmetics industry. It explained the science, in particular the chemistry, behind various products, such as soap and detergents, we consider essential for day to day living.
The article explained how soap worked. Soaps consist of negative ions, made up of a polar and head non-polar tail. The head has an affinity for water, while the tail has an affinity for grease and oils. This means that oil and grease can be dissolved in soapy water. However soap has a pH of ca 10 and leaves an alkaline residue, destroying the skin’s acid mantle. Another disadvantage of soap is that it is not good at removing small particles, such as make up from the skin. Instead cleansers are often used. Cleansers consist of an emulsion, which is rubbed into the skin and then wiped off, leaving a moisturising film on the skin. They so well because the emulsion is able to carry water much deeper into the skin than oil by itself, making it much more moisturising.
Cosmetic products for our hair were also mentioned in the article. Modern shampoos are made up of many different ingredients, including synthetic detergents, perfumes, colour, preservatives, viscosity modifiers and foaming boosters. The main challenge facing scientists in recent years has been to create a shampoo containing conditioners to replace the moisture lost during washing. This was very difficult as because the active ingredients in shampoos and conditioners are oppositely charged. This been achieved using cationic polymers, which are compatible with anionic detergents.
Overall the article gave me a greater understanding of the products I use daily on my skin and hair and the explanations behind them. Now if only they could come up with a n allover beauty potion.
Rosemary Black 11D