Perhaps, in childhood, my mother more often than others asked one question: “Wash your hands with soap and water?” Without exception, everyone knows that unwashed (or poorly washed) hands can cause both a small indigestion and serious diseases such as intestinal infections, cholera, hepatitis A, polio, etc.
For most of us, the need to observe hygiene rules is beyond doubt. Washing hands after a walk, before eating, after going to the toilet - these are the same obligatory rituals, such as, say, greeting friends. But not everyone thinks what the soap we use is made of.
What is soap?
We are used to the fact that soap is a fragrant bar that dissolves and foams under the influence of water. This foam rinses off the dirt and your hands are clean. Elementary knowledge of chemistry allows us to give a more accurate explanation: the molecules that make up the soap are combined with non-polar molecules of substances trapped in the hands (fat, dirt, etc.). The same soap molecules are easily connected with polar molecules of water. It turns out that the chemical composition of soap is a kind of mediator between water and greasy contaminants. Soap combines with dirt molecules and “clings” to water. And water, in turn, flushes these compounds from the skin of the hands.
Chemical terminology
In terms of chemistry, soap is an emulsifier for the fat-water system. The soap molecule is extended into a snake, in which the tail is hydrophobic and the head is hydrophilic. Hydrophobic, that is, a fat-soluble tail, immersed in pollution, firmly connected with it. The head turns to water molecules. Such a droplet system is called a micelle. The fat in these compounds is no longer felt by us as “slippery”.
The effect of a greasy film on water instantly disappears when a small amount of soap (no matter solid or liquid) is added to it. Micelles form instantly and bind fat molecules. Water, under the influence of what soap is made of, becomes softer and even “thinner”. These new properties allow it to penetrate deep into the tissue and wash out all kinds of contaminants from there.
The same effect of thinning water can be achieved by simple heating. For materials with a non-porous surface, hot water is sufficient to remove all greasy contaminants. You can safely wash the dishes without soap in hot water, but you will have to wash off the grease with soap already.
How much soap do you need
So, we already know that micelles - compounds of soap with water and fat - are quite stable drops. And their size is small due to exposure to temperature. How to determine how much soap you need? The easiest way is to achieve foaming. After all, the presence of soap foam indicates an abundance of soap formations unbound by fat molecules in micelles. Since all micelles are negatively charged, they repel each other and cannot unite. But it is enough to appear a small drop of fat, and part of the unbound molecules of the soap solution will merge with it into a more stable compound. And the bound molecules of the detergent cannot give foam formations.
The chemical composition of the soap
In an attempt to figure out what soap is made of, you will have to recall a little more a school chemistry course. Soaps are various salts (carbonic, sodium or potassium).
Salt in terms of cooking is clear to us. And in chemistry? These are the products of the interaction of alkali and acid. In nature, we often meet individually the first and second. But there is no soap in nature. And although the production of soap is a simple matter, but it still requires certain knowledge and skills.
For saponification (obtaining a foaming substance with detergent properties), it is necessary that the usual fatty acids react with alkali. The latter breaks down fatty acids into glycerol and fatty acids. The sodium (potassium) component of the alkali reacts with the acid, and the sodium (potassium) salt of fatty acids is formed, which we know as soap.
Natural or synthetic soap
When you take a bar of detergent from the store counter and carefully read out what soap is made of, you will not always find natural coconut or olive oils in the composition. In industry, soap is boiled from refinery waste. It turns out a synthetic detergent that has nothing to do with natural soap. On the one hand, synthesized products surround us everywhere, and there is nothing wrong with that. On the other hand, I want to use a real, that is, a natural product. As already mentioned, such a product appears in the process of "saponification" or soap making. In practice, extracting glycerin from soap is very difficult, so natural soap is softer and has a better effect on the skin. Glycerin is the most important component of soap, as this natural moisturizer is able to absorb moisture from the air and transfer it to the skin. Thus, the skin does not dry out and remains sufficiently elastic.
A variety of soap oils
Each natural oil has its own characteristics. To give the soap certain properties, it is necessary to boil the soap from one or another natural oil.
Coconut oil foams well, for example. And olive contains a huge amount of minerals and acids useful for the skin. More exotic canola oil (rape varieties) and already familiar palm oil are excellent conductors of beneficial substances to the skin. Sunflower oil is most often not used for boiling soap bars. But for cream soap, it is an excellent component.
Synthetic components
Industrial-made soap is very diverse. Color, smell, properties, etc. But it should be remembered that both the smells and the color of the soap are just chemicals created in the laboratory. Of course, manufacturers repeatedly test the effect of all components on the skin condition, but in exceptional cases, individual intolerance of individual elements is possible.
The same can be said about natural essential oils. Despite everything, an individual negative reaction to a specific component is possible. Nevertheless, handmade soap has much less negative impact on skin condition.
The second important nuance is the color of soap. It can also be obtained synthetically or through natural dyes. Natural paints are "duller" and "wilderness", but, of course, they are harmless in comparison with their chemical competitors.
Laundry soap
Soap farmers distinguish between cosmetic and laundry soap. According to its name, laundry soap is designed to wash and wash household items, not skin. However, cosmetologists recommend not abandoning the use of laundry soap to restore hair and skin.
The composition of laundry soap (GOST distinguishes 3 types) is characterized by a high content of fatty acids and alkali. Actually, according to the content of acids, natural vegetable and animal oils and alkalis, soap is of such categories: at least 70.5%, at least 69% and at least 64%. This type of soap does not cause allergies at all, which allows it to be used even for children's things.
Laundry soap is considered as a natural antiseptic. For this purpose, it is used when cleaning in hospitals. Dentists recommend lathering each toothbrush after each use so that it does not become a breeding ground for bacteria.