Perhaps, in my childhood, my mother often asked one of the other questions: "Did you wash your hands with soap?" Everyone knows without exception that unwashed (or badly washed) hands can cause both a small stomach upset and serious diseases such as intestinal infections, Cholera, hepatitis A, poliomyelitis, etc.
For most of us, the need to observe hygiene rules is undeniable. Washing hands after a walk, before eating, after going to the toilet - the same mandatory rituals, as, for example, greet friends. But not everyone thinks about what the soap we use is made of.
What is soap?
We are used to the idea that soap is a fragrant bar, which under the action of water dissolves and foams. This foam cleans the dirt, and the hands are clean. Elementary knowledge of chemistry makes it possible to give a more precise explanation: the molecules that make up the soap are combined with nonpolar molecules of substances found on hands (fat, dirt, etc.). These same soap molecules can also be easily combined with polar molecules of water. It turns out that the chemical composition of soap is a kind of intermediary between water and greasy soiling. Soap combines with molecules of mud and "clings" to water. And the water, in turn, washes away these connections from the skin of the hands.
From the point of view of chemistry, soap is an emulsifier for the fat-water system. The soap molecule is stretched into a snake, in which the tail is hydrophobic, and the head is hydrophilic. Hydrophobic, that is, fat-soluble tail, plunging into the contamination, firmly connects with it. The head turns to water molecules. Such a system of drops is called a micelle. 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 whether solid or liquid) is added to it. Micelles are formed instantaneously and are bound by fat molecules. The water under the influence of what it is made of soap becomes softer and even "hotter". These new properties allow it to penetrate deeply into the tissues and wash out all kinds of pollution.
The same effect of water dilution can be achieved by simple heating. For materials with a non-porous surface, enough hot water is sufficient to remove all greasy dirt. You can safely wash dishes without soap in hot water, but with hands you have to wash off the fat already with soap.
How much do you need soap
So, we already know that micelles - the compounds of soap with water and fat - are fairly stable drops. And their size is small due to the effect of temperature. How to determine how much soap is needed? The easiest way is to achieve foaming. After all, the presence of soap foam indicates the abundance of soap-free soap molecules in the micelles. Since all micelles are negatively charged, they repel each other and can not unite. But it is enough to appear a small drop of fat, and some of the unbound molecules of the soap solution will merge with it into a more stable compound. A bound molecule of detergent can not give foam formations.
Chemical composition of soap
In an attempt to understand what the soap is made of, it will be necessary to recall a little school chemistry course. Soap - a variety of salts (carbon, sodium or potassium).
Salt from the point of view of cooking we understand. And in chemistry? It is the reaction products of alkali and acid. In nature, we often meet individually and the first and second. But there is no soap in nature. And although the production of soap is a simple matter, it still requires certain knowledge and skills.
For saponification (producing a foaming substance with detergent properties), it is necessary that the fatty acids habitual for us react with alkali. The latter breaks down fatty acids into glycerin and fatty acids. The sodium (potassium) constituent 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 counter of the store and carefully read out what the soap is made of, you can not always find natural coconut or olive oil. In the industry, soap is brewed from refinery waste. It turns out a synthetic detergent that does not have anything in common 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 the present, that is, a natural product. As already mentioned, such a product appears in the process of "saponification" or soap making. In practice, it is very difficult to extract glycerin from soap, so natural soap is softer and better affects the skin. Glycerin is the most important component of soap, since this natural moisturizer is able to absorb moisture from the air and transfer it to the skin. Thus, the skin is not overdried and remains sufficiently elastic.
Variety of soap oils
Each natural oil has its own characteristics. To give soap certain properties it is necessary to boil soap from this or that natural oil.
Coconut oil perfectly foams, for example. And olive contains a huge amount of minerals and skin-friendly acids. More exotic canola oil (varieties of rape) and already familiar palm oil are excellent conductors of useful substances in the skin. Sunflower oil is most often not used for cooking soap bars. But for cream soap it is an excellent component.
Industrial boiled soap is very diverse. Color, smell, properties, etc. But it should be remembered that both smells and color of 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. In spite of everything, an individual negative reaction to a particular component is possible. Nevertheless handmade soap has much less negative effect on the skin condition.
The second important nuance is the color of soap. It can also be obtained synthetically or by natural dyes. Natural paints are "muddy" and "deaf", but, of course, they are harmless in comparison with their chemical competitors.
Soaps distinguish cosmetic and household soap. According to its name, laundry soap is designed to wash and wash household items, not skin. However, beauticians recommend not to abandon the use of laundry soap to restore hair and skin.
The composition of laundry soap (GOST distinguishes three 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 kind of soap does not cause allergies at all, which makes it possible to apply it even for children's things.
Household soap is considered as a natural antiseptic. It is for this purpose that it is used for cleaning in hospitals. Dentists recommend after each use soap the toothbrush so that it does not become a hotbed of bacteria.