Commonly used cleaning agents can be classified in different ways, such as cement self-leveling. For example, they can be divided into inorganic chemical cleaning agents and organic chemical cleaning agents according to their chemical composition; if some cleaning agents may have different effects on different dirt, or have two or more effects on the same dirt, then they should be classified according to their main effect under normal circumstances.
1. Water and non-aqueous solvents
The solvent of dirt refers to those substances that can strip off the dirt of the cleaning object in the form of dissolution or dispersion without generating new substances with stable and determined chemical composition. It includes water and non-aqueous solvents.
(1) Water: Water is the most important solvent existing in nature. In industrial cleaning, water is both the solvent for most chemical cleaning agents and the solvent for many dirt. In cleaning, wherever the dirt can be removed by water, non-aqueous solvents and various additives will not be used.
(2) Non-aqueous solvents: Non-aqueous solvents include hydrocarbons and halogenated hydrocarbons, alcohols, ethers, ketones, esters, phenols and their mixtures. They are mainly used to dissolve organic dirt, such as oil dirt and certain organic compound dirt.
2. Surfactants
Its molecule has both hydrophilic polar groups and lipophilic non-polar groups. When a small amount is added, it can greatly reduce the surface tension of the solvent (usually water) and the liquid interface tension, and has the functions of lubrication, solubilization, emulsification, dispersion and washing.
There are many ways to classify surfactants. Generally, they are classified according to their ionization state in the solvent and the type of hydrophilic group ions. The most commonly used ones are anionic surfactants, cationic surfactants, amphoteric surfactants, and non-ionic surfactants. The first three are ionic surfactants.
Surfactants have a wide range of uses in household life and industrial production cleaning.
3. Acid-base cleaning agents
Cleaning agents that rely on acid-base reactions with dirt (sometimes accompanied by oxidation-reduction reactions), transforming dirt into substances that can be dissolved or dispersed in the cleaning solution, are mostly organic acids, inorganic acids, alkalis, and salts that become acidic or alkaline after hydrolysis.
Most acid-base cleaning agents consist of aqueous solutions of acids and alkalis with necessary additives. Another type is acid or alkali that reacts with dirt in a molten state under high temperature conditions, converting dirt that was originally insoluble or difficult to dissolve in the cleaning medium into easily soluble compounds. These acids and alkalis are usually called fluxes. This type of cleaning agent has good results when removing dirt that is difficult to clean with solvents or solutions.
4. Oxidation-reduction agents
Preparations that mainly remove dirt by means of oxidation-reduction reactions with dirt are cleaning oxidizing agents or reducing agents, including fluxes.
Oxidizing agents are used to remove reductive dirt, such as many organic dirt. Reducing agents are used to remove oxidative dirt, such as rust dirt.
5. Metal ion chelating agents
By means of coordination reactions with metal ions in dirt, the dirt is transformed into chelates that are easily soluble in the cleaning agent. Such cleaning agents or additives are chelating agents. They are commonly used in the cleaning of rust dirt and inorganic salt dirt.
6. Adsorbents
Substances that remove dirt through physical or chemical adsorption on the dirt are adsorbents for cleaning purposes. Adsorbents with strong affinity for dirt should be selected for cleaning.
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