What is the principle of detergent degreasing?

It is based on the principle of emulsification. Specifically, mainly with the help of emulsifiers, generally it is an amphiphilic molecule (both hydrophilic and lipophilic), the lipophilic end of the emulsifier can wrap the oil stain on the clothes inside, and the hydrophilic end is exposed outside. According to the principle of similarity and dissolution, the "oil stains on clothes" wrapped in the emulsifier can be dispersed into the water and washed off.

The structure of dish soap is divided into two parts, which are shaped like ——

One end (polar) is a hydrophilic group that is easy to combine with water, and the other end (non-polar) is a lipophilic group that is easy to combine with oil.

When the dish soap is dissolved in water to clean the dirt, the lipophilic group is inserted into the oil and the hydrophilic group is surrounded by a large number of water molecules. (like an arrow inserted into the body of a prey) was rubbed and the dirt was dragged off the utensils and clothing.

We use shampoo to make use of a similar principle. It's just that shampoo washes off the oil secreted by the hair.

Detergent to remove oil stains is a kind of emulsification, sodium hydroxide and other strong alkali degreasing principle is very different, is the use of high temperature oil in a strong alkali solution saponification reaction to produce carboxylate sodium salt and glycerol.

There are two main categories of detergents: one is fertilizer (fragrant) soap; The second is synthetic detergents. Among the synthetic detergents, laundry detergent accounts for about 2 3, liquid detergents account for about 1 3, and solid synthetic detergents are relatively few.

Detergents contain surfactants such as sodium dodecyl sulfonate, which are the reason why they become emulsifiers. After dissolving in water, the lipophilic group extends into the oil molecules, and the hydrophilic group extends into the water molecules to form an emulsion, which uses this principle to remove oil stains.

In addition, emulsification to remove oil stains and reaction to remove oil stains are common examples in life: soap is also an emulsifier, which is sodium carboxylate formed after the saponification reaction of oil and sodium hydroxide, which has the same effect as sodium dodecyl sulfonate.

Because: 1. Detergent can enhance the dispersion and suspension ability of dirt. Its surfactant has the ability to emulsify, which can emulsify the oil into small oil droplets and disperse them in water to prevent the oil beads from re-accumulating.

Surfactants can also charge the surface of solid dirt, using the repulsion between the same charges to disperse the solid dirt in the water and prevent the redeposition of the dirt.

2. It contains surfactants and emulsifiers, which are lipophilic and will disperse the oil.

3. The main ingredient of dish soap is surfactant, which is an organic compound containing two parts of hydrophilic group and lipophilic group in molecular structure. Many lipophilic groups are inserted into the oil to form hydrophilic groups on the surface of the oil, and the hydrophilic groups can be dissolved in water, and then peeled off when they are dissolved along with the oil.

It is mainly based on the principle of emulsification. Specifically, with the help of emulsifiers, the general emulsifier is an amphiphilic molecule (both hydrophilic and lipophilic), the lipophilic end of the emulsifier can wrap the oil stain on the clothes inside, and the hydrophilic end is exposed outside. According to the principle of similarity and dissolution, the "oil stains on clothes" wrapped in the emulsifier can be dispersed into the water and washed off.

The main ingredients of dish soap are sodium alkyl sulfonate, sodium fatty alcohol ether sulfate, foaming agent, solubilizer, fragrance, water, coloring and preservatives. Sodium alkyl sulfonate and sodium fatty alcohol ether sulfate are both anionic surfactants and petrochemical products, and their main role is to remove oil stains.

Gasoline decontamination uses the principle of dissolution; Detergents are used for emulsification.

Gasoline can not be dissolved in water, but can be dissolved in organic solvents, so gasoline decontamination is the use of gasoline can dissolve oil pollution to achieve the purpose, detergent can not dissolve oil stains, but can play an emulsifying role, can disperse large oil droplets into fine oil droplets with water to wash away, so as to decontaminate.

Using the principle of similar dissolution, it can be seen that organic matter can be dissolved in organic matter, and according to detergent decontamination, large oil droplets are dispersed into fine oil droplets and washed away with water.

The principle of degreasing with detergent: the water with detergent has an emulsifying effect, which can emulsify the oil and is easy to wash.

Gasoline degreasing principle: Gasoline cleaning oil is due to the fact that oil can be dissolved in gasoline.

The difference between the two: the principle of degreasing with detergent is a chemical reaction, and the principle of degreasing with gasoline is a physical effect.

Degreasing with detergent is emulsification.

Supplement: Emulsifiers are a class of organic compounds that can form a stable emulsion from immiscible liquids. They are all surface-active substances that reduce the interfacial tension between liquids and make immiscible liquids easy to emulsify.

In emulsification, the dispersed phase is evenly distributed in a continuous phase in the form of very small liquid beads (between microns and tens of microns in diameter), and the emulsifier forms a thin film or electric double layer on the surface of these liquid beads to prevent them from coaggregating each other and maintain the stability of the emulsion.

Gasoline is used to remove oil because both are organic matter, and similar ones are soluble and dissolved.