The different degree of polymerization of the same surfactant has a great influence on the size and dispersion of ZnO nanoparticles. Wu Wei et al. Studied the effect of PEG with different molecular weight on the size and dispersion of ZnO nanoparticles. The results show that nano ZnO modified by PEG in situ can disperse Zn (OH) 2 by adsorbing on the surface of Zn (OH) 2 precursor and depending on the steric hindrance effect produced by the long chain structure of PEG. If the molecular weight of PEG is too small, it can not play the role of steric hindrance. If the molecular weight of PEG is too large, the intermolecular force between particles will be enhanced and agglomeration will occur.

The development potential of flame retardants in the domestic market is still huge. With the further improvement and implementation of fire prevention and flame retardant laws and regulations in China and other emerging markets, the application areas and demand scale of flame retardants will be further expanded.

In the process of surfactant promoted bioremediation, different types of surfactants will get different remediation results due to their different characteristics, and if the critical micelle concentration is not reached, the surfactant has no solubilization effect. If the concentration is too high, it may inhibit the microbial degradation. Therefore, in the actual remediation of soil, surfactant with good type and concentration should be used.  

When the surfactant is added into the liquid, even if the concentration is very small, it will spontaneously cause a strong reduction of the surface or interfacial tension. Surfactants are amphoteric in structure. One end of the surfactant is hydrophilic and the other is hydrophobic. The amphoteric molecules will self orientate on the surface of the solution, the polar groups extend to the water, while the hydrophobic hydrocarbon groups extend to the air or oil interface, thus reducing the surface tension of the liquid. Surfactants can emulsify, disperse, solubilize, moisten, foaming, defoaming, lubricating, washing, softening, antistatic and anti-corrosion.

Biosurfactants are the rising star in the surfactant family. They are a kind of biological macromolecular substances with surface activity produced by microorganisms. Most of them are produced by bacteria, yeasts, fungi (molds). Biosurfactants produced by microorganisms can be divided into five categories according to their chemical composition and microbial sources, including glycolipids, fats, polysaccharide protein complexes, phospholipids and fatty acids or neutral lipids. Many microorganisms can secrete biosurfactants (see Table 1). Most biosurfactants are anionic, and their CMC is usually in the range of 1-200 mg / L, and its molecular weight ranges from 500 to 1500 da. A kind of

In the process of surfactant promoted bioremediation, different types of surfactants will get different remediation results due to their different characteristics, and if the critical micelle concentration is not reached, the surfactant has no solubilization effect. If the concentration is too high, it may inhibit the microbial degradation. Therefore, in the actual remediation of soil, surfactant with good type and concentration should be used.   

Friends who often use sealants will find that the adhesion effect caused by changing different products is also different. Some high-grade sealants imported from abroad have better effect, and some brand products are better. In short, there will be differences.

Containers for amino terminated polyether can be made of steel, aluminum, polyethylene or polypropylene. The storage temperature should not exceed 70 ℃. In order to prevent moisture absorption and oxidation, it is recommended to fill the container with nitrogen. We usually pack them in clean, dry, sealed, leak free galvanized iron drums. Keep away from the sun, rain and fire during storage. It is not restricted by the storage rules of flammable liquids, but it should be avoided to enter groundwater or surface water because it is not easy to be biodegraded.

The application of surfactants in the field of disinfection has developed rapidly in recent years, and the variety and quantity of related products approved for market are increasing. In summary, alkyl glycosides are mainly manifested in four aspects: 1) direct use of surfactants with bactericidal effect, and constantly introduce new varieties; 2) adding surfactants to traditional disinfection drugs to improve and improve the disinfection effect, so as to achieve the purpose of increasing efficiency;

According to the different types of sealant, different industries are used. No matter what industry is used, preparation measures should be taken before use. For example, for the use of door and window sealing, the dirty things on the doors and windows should be removed first, and then used, so as to increase the sealing effect.

Surfactants are substances that can significantly reduce the surface tension and interfacial tension of liquids. Their molecules are composed of polar hydrophilic group and nonpolar hydrophobic group. The hydrophilic part is carboxyl group, sulfate group, sulfonic group, amine group, quaternary ammonium group and hydroxyl group, while the hydrophobic part is represented by long-chain alkanes and aromatic hydrocarbons.

The mechanism of biosurfactant promoting the degradation of organic pollutants and the interaction between biosurfactants and degrading bacteria and substrates are still unclear. Although biosurfactants promote microbial degradation, they also have some inhibitory factors. For example, some surfactants are toxic to microorganisms when the concentration is above CMC, and some biosurfactants colloidal particles can interfere with cell processes.

When the amino terminated polyether is applied, its uncured foam is sticky to the skin and clothes. Do not touch the skin and clothing when using. The pressure of 5-6kg/cm2 (25 C) in the tank can not be touched. The temperature in storage and transportation should not exceed 50 C, so as to prevent the explosion of the foam tank in the tank. We should avoid direct sunlight, and strictly prohibit the contact of the children. The used styrofoam cans should not be thrown around. Burning or piercing empty cans is prohibited. Keep away from open fire and keep away from flammable and explosive materials. The construction site of amino terminated polyether should be provided with ventilation conditions. Construction personnel should wear work gloves, work clothes and goggles during

In the application of flame retardant, there are also various defects. There are few flame retardant products in powder coating industry on the market, and the flame retardant mechanism is different. In order to achieve better flame retardant effect, the dosage of flame retardant is generally about 5-10%, which will cause certain damage to the coating film, and will also be greatly affected in the process of powder coating processing.

The flame retardancy of plastic powder polymer is very poor, which is limited in many fields. The flame retardant powder coating has the functions of flame retardant, flame retardant and heat insulation. With the rapid development of industry, the requirement of flame retardant is more and more urgent. The substances that can play the role of flame retardant are mainly the N group and halogen group elements in the periodic table of elements. The commonly used compounds are n, P, Cl, Br, Mg, Al and other elements. Economic flame retardant products such as magnesium hydroxide and other compounds, similar to this kind of products, we call them flame retardants.

A surfactant in which the hydrogen atoms of the hydrocarbon chain in the surfactant molecule are completely or partially replaced by fluorine atoms. Fluorinated surfactants can be called both fluorocarbon surfactants and fluorocarbon surfactants. Their unique properties can be summarized as "three high" and "two hydrophobic", that is, high surface activity, high thermal stability and high chemical stability. Its fluoroalkyl groups are both hydrophobic and oleophobic. The unique properties of fluorine surfactants are related to the properties of fluorine atoms and carbon fluorine bonds. First of all, because fluorine is a highly electronegative element, the bond energy of C-F bond is very high. Secondly, the radius of covalently bonded fluorine atom is larger than that of hydrogen atom, which can effectively protect perfluorinated C-C bond. Therefore, fluorine surfactants have high thermal and chemical stability.

The molecular structure of amphoteric surfactants has hydrophobic and hydrophilic groups. The properties related to surface tension can be adjusted by changing the structure of hydrophilic part of surfactant molecule. For example, polymethylsiloxane (silicone resin) is more effective, and the unique surface activity of silicone oil is due to the hydrophobic Si - O group being shielded by hydrophilic methyl groups. Fluorinated alkyl group can further reduce the surface tension, fluorine atom has the appropriate covalent radius to shield the carbon chain from space, and the fluoroalkyl group has little interaction with other groups. Fluorosurfactants can be seen from the example of perfluorooctanoic acid [n - c7f15cooh], where the mass fraction of perfluorooctanoic acid is 0101%, the surface tension of water decreases from 72 Mn / m to 1512 Mn / m.

According to the flame retardant standard, phase flame retardant, also known as flame retardant, fire retardant or fire retardant, is a general term for substances that can hinder flame combustion. According to the composition, flame retardants can be divided into organic flame retardants, inorganic flame retardants and so on. Its action principle includes physical principle, chemical principle and so on. Flame retardants are widely used in building and textile materials. Flame retardant plastics are the main flame retardant products.

With the progress of science and technology and the improvement of living standards, polymer materials, especially synthetic polymers, such as plastics and rubber, are playing a more and more important role in people's life, and their applications are expanding year by year. However, most of the organic polymer materials have different degrees of flammability in the air. In order to realize their application in military, aerospace, transportation, power and civil industries, flame retardant modification of them has become a new topic. The ideal method of flame retardant modification of plastics is to improve the fire resistance of plastics by adding flame retardant or flame retardant masterbatch.

Generally speaking, organic flame retardants have good affinity. In plastics, brominated flame retardants occupy an advantage in organic flame retardant systems. Although there are many criticisms on environmental protection, it is difficult to be replaced by other flame retardant systems.