Silicone Surfactant

Excellent Surface Tension Reduction: Silicone surfactants excel in reducing surface tension, enhancing their performance in various applications.
Outstanding Wetting Performance: Their hydrophobic nature contributes to exceptional wetting capabilities.
Antifoaming and Foam Stabilization Properties: Silicone surfactants are effective in both preventing and stabilizing foam, making them valuable in diverse industries.
Low Toxicity and Physiologically Inert: Silicone surfactants exhibit low toxicity, making them suitable for use in personal care and pharmaceutical applications.
Effective Emulsification and Compatibility: Their versatile structure allows for effective emulsification and compatibility in different media.
Silicone Surfactants: Critical Micelle Concentration (CMC).
Efficiency in silicone surfactants is often determined by Critical Micelle Concentration (CMC), indicating the minimum concentration needed to reduce water surface tension. Understanding CMC values is crucial for comparing and selecting silicone surfactants based on their effectiveness as biosurfactants.

Silicone surfactants are a new type of adjuvant, which occupies an important position in the national economy and modern industrial and agricultural production. Through a review of the application of silicone surfactants in the field of pesticides, daily chemicals and the textile industry, The development prospects are prospected, and the main development directions of specialization, specialization, green and high-efficiency silicone surfactants are proposed.

Silicone surfactants are a large class of organic substances. Their characteristics are extremely characteristic, they are extremely flexible and universal, and they have great use value.

Surfactants have been used as demulsifiers, oil-displacing agents, anti-caking agents, deodorants, antistatic agents and other dozens of experimental reagents for daily life and many industrial and agricultural production fields. Although its usage is not large, it can play a key role in increasing product variety, reducing cost measures, saving resources, and ensuring quality.

Silicone surfactants are a type of surfactant composed of polydimethylsiloxane as its hydrophobic backbone and one or more organic silicon polar groups connected to the meta or terminal positions. According to the chemical properties of the hydrophilic group R in its chemical structure, silicone surfactants can be divided into four categories: anionic, cationic, nonionic, and zwitterionic. Among them, nonionic surfactants are the most studied. , The most widely used. Now, Xinjiayi will take you to understand the classification of silicone surfactants:

Cationic Silicone Surfactant
If the R group contains structural units such as alkyl quaternary ammonium compounds, amido quaternary ammonium compounds and imidazoline derivative quaternary ammonium compounds, it is called a cationic silicone surfactant. Among cationic silicone surfactants, cationic polysiloxane quaternary ammonium salt surfactants are the most widely used. The cationic polysiloxane quaternary ammonium salt surfactant has a large molar mass and can be compatible with anionic surfactants. It has no irritation to human skin and eyes. It has certain antibacterial ability. It does not produce free ammonium in alkaline solution. stable. The macromolecule of this product contains hydrophobic long-chain polysiloxane chain, which makes it have excellent smoothness and softness.

Anionic Silicone Surfactant
When the R group contains structural units such as phosphate, sulfate, carboxylate, sulfonate, and sulfosuccinamide ester, it is called an anionic silicone surfactant. When R is the structure shown in the figure below, it is called anionic polysiloxane phosphate salt surfactant.
When R'is a fatty acid functional group, it is a polysiloxane phosphate betaine amphoteric surfactant. The surfactant molecule not only has the structure and characteristics of phosphate betaine, but also has the structure and characteristics of polysiloxane. If a low molar mass polysilane is selected, the polysiloxane has weak properties; on the contrary, if a large molar mass polysiloxane is selected, the polysiloxane has significant properties. This kind of product has the characteristics of low toxicity, antibacterial, hard water resistance, and good compatibility with various surfactants.

Non-ionic Silicone Surfactant
When the R group contains units such as polyether, alkanolamide, ester, glycoside, etc., it is nonionic surfactant. Among them, polyether silicone surfactants are the most widely used.
Non-ionic polyether silicone surfactant is a combination of polysiloxane segment (A) and polyether segment (B). The combination methods are: AB type, ABA type, BAB type, (AB) Types such as n type, branched chain type and side chain type. There are two ways to connect the polyether segment and the siloxane segment, namely the Si-O-C type and the Si-C type. The former is unstable and belongs to the hydrolyzed type; The latter is stable to water and is called the non-hydrolyzed type.

●The application of surfactants in the textile industry
Silicone surfactants are widely used in the textile industry. For example, in spinning, spinning, desizing, knitting or knitting, scouring (refining and bleaching), coloring, garment printing, finishing and other textile processing procedures, surfactants or surfactants are needed as the core. Modifiers to enhance the effect, optimize the processing technology, improve performance and ensure quality. Among the ionic surfactants, anionic surfactants are mainly used as detergents, penetrating agents, wetting agents, demulsifiers and thickeners, etc.; cationic surfactants, because the fibers are more negatively charged, can be firmly absorbed on the textile It is often used as fabric softener, leveling agent, waterproofing agent, antistatic agent and fixing agent, etc.; amphoteric surfactant is generally used as leveling agent for metal complex dyes, fabric softening agent and antistatic agent.

●Application of surfactants in tannery and fur industry
The processing process of the tannery is very complicated and cumbersome, and it needs to go through multiple processes from naked leather to finished leather. Before tanning, soaking, liming, enzyme softening, pickling and deacidification, degreasing and other preparations are required; after tanning, coloring, fatliquoring, and finishing are also required. In all these processes, surfactants are needed as modifiers to promote the physical and chemical effects and processes of each process, reduce the production cycle, improve the quality of finished leather, and save chemical raw materials.

The main functions of silicone surfactants in leather product production and fur processing are dissolution, emulsion, wetting, penetration, foaming, defoaming, cleaning, leveling and color retention, etc. In each process, it has different requirements for its role. For example, in soaking, it is mainly required to have wetting and penetrating effects; in degreasing, it is required to act as emulsion, wetting and penetrating; in decontamination, it is required to have Excellent solubilization; coloring requires it to have excellent diffusion, infiltration and foaming effects; for fatliquoring, it is required to have excellent emulsion properties, etc.

Silicone surfactants such as a dimethicone copolyol contain hydrophobic and hydrophilic portions enabling them to lower the surface tension of water.1 The reduction of surface tension is a necessary first step in providing foam, emulsification, wetting and other surfactant properties. Each of these surfactant properties requires a molecule that lowers surface tension. Put another way, all molecules capable of foaming, emulsifying or wetting must be able to lower the surface tension, but not all molecules that lower surface tension provide these properties. The lowering of surface tension depends on the presence of hydrophilic and hydrophobic portions in the molecule. Additional surfactant properties depend on the structure of the molecule and its activity at the surface.

The function of dimethicone copolyol or any other silicone compound alone in aqueous solution may be of academic interest. However, it is of limited interest to a formulator because formulations are never simply water and dimethicone copolyol. The key to formulation is the interaction between the surfactants and other ingredients that alter the performance of the surfactants at the surface. There are interactions between different formulation components and understanding them and optimizing them for a given effect is key to formulation success.

Surface Tension in Aqueous Solutions
Aqueous solutions were prepared with the various materials at 1% by weight. The surface tension of each material was determined using a tensiometera.

Table 2 lists the results and clearly shows that the sulfated fatty alcohol surfactants have a surface tension in the range of 30–32 dynes/cm2. The silicone surfactants have lower surface tension, in the range of 21–28 dynes/cm2. The variation of surface tension within the class of silicone compounds is noteworthy. There has been a tendency to make generalizations that all silicone surfactants have essentially identical surface tension values. Clearly, this is not the case. As the silicone molecule contains less and less silicone, the surface tension becomes more like that of a fatty surfactant.

The surface tension is determined by the orientation of the surfactant molecule at the air/water interface. More specifically, surface tension is determined by the orientation of the organic functional groups on the surfactant molecule. These groups include silicon-containing portions, methyl groups, methylene groups and polyoxyalkylene groups. Action at the interface depends on the group that predominates at the surface when the molecule is in the lowest free energy conformation. The silicone portion of the molecule has an abundance of methyl groups, which makes the surface tension lower. The fatty surfactant groups have an abundance of methylene groups (-CH2-), which makes the surface tension higher.

It is important to note that all silicone surfactants do not have the same low surface tension. Molecules that have long chains of ethylene oxide or propylene oxide have surface tensions like fatty surfactants, not silicone surfactants. As will be shown, the performance in formulations is complex; it depends upon the other components present.

Surface Tension in Binary Mixed Systems
Water is a unique material in that it orientates itself by hydrogen bonding. A hydrogen bond is a special type of dipole-dipole force that exists between an electronegative atom and a hydrogen atom bonded to another electronegative atom. Hydrogen bonding results in an orientation of molecules that have the lowest energy in the solution. This lowest energy state is favored. It results in the high surface tension of water. The reason oil and water separate from each other is that the two separate phases are at lower energy than when they are together. Simply stated, the number of hydrogen bonds between water molecules that need to be disrupted to keep oil in a water phase results in the separation of the phases being the lowest energy.

Surfactants (fatty or silicone) experience hydrogen bonding in water. If there are several different surfactant types in water the interaction becomes more complicated albeit still driven by achieving the lowest energy.

The combination of SLS or SLES-2 with the various dimethicone copolyols suggests numerous possible interactions:

•Interactions from incompatibilities of the silicone, fatty and water-soluble domains in the surfactant. As with the oil and water interaction just described, these domains are incompatible with each other.

•Interactions from hydrogen bonding occurring between polyoxyalkylene domains of one molecule interacting with polyoxyalkylene domains or polar domains on another molecule. The nature of all of these interactions collectively determines the surface tensions of the various blends.