Views: 0 Author: Site Editor Publish Time: 2023-02-24 Origin: Site
When it comes to cleaning products, we have to talk about surfactants. Soap is actually a kind of surfactant, and it is also the first surfactant that humans come into contact with. As a qualified ingredient party, surfactants have to be clarified.
Surfactant is the main active ingredient of cleaning products. Its function is far more than washing effect, but also emulsification or demulsification, foaming or defoaming, moistening or dewetting, dispersion and solubilization. These functions determine the important position of surfactants in daily life
Different surfactants have different effects on the skin, and they are divided into 4 categories according to the different charges on the hydrophilic end after they are dissolved in water:
Anionic surfactants are the most common active ingredients in cleansing cosmetic products. They have strong cleaning power, rich foam and low price. They are also the initial and widest cleaning raw materials for detergent industrial applications (such as soap)
In a neutral or slightly alkaline aqueous solution, anionic surfactants form negatively charged high-subgroups, which reduce the interfacial tension of lipids on the skin surface to disperse and dissolve in water, thereby achieving a cleaning effect. However, it will destroy the fatty film of the skin and is irritating to a certain extent.
Cationic surfactants can dissociate surface-active cations in water, adsorb on the interface like other surfactants, and form micelles when a certain critical micelle concentration (CMC) is reached, thereby reducing the surface tension of the solvent, resulting in washing and dispersing , emulsification, solubilization, moistening and thickening
Cationic surfactants have limited cleaning effect and weak cleaning power, but have strong antibacterial ability and strong affinity to hard surfaces, and are easy to adsorb on skin, hair and teeth. They are often used in hair conditioners, skin softeners and oral products. ;It is highly irritating to the skin and has a certain cytotoxic effect
Amphoteric surfactants refer to a class of surfactants that have both cationic hydrophilic groups and anionic hydrophilic groups in their molecular structure, and show an isoelectric point in solution.
In addition, amphoteric surfactants have excellent rheological properties, such as hydrotropy, calcium soap permeability, and good biodegradability. This type of surfactant has weak irritation to the skin and mucous membranes, is resistant to hard water, and has a high concentration of electrolytes, which has a certain antibacterial effect. These characteristics make amphoteric surfactants widely used in cosmetic formulations. Usually found in lecithin, amino acid and betaine forms
Nonionic surfactants are dissolved or suspended in aqueous solutions, do not form charged ions, and rely on their complete neutral molecules to reflect surface activity.
Nonionic surfactants have high surface activity, low surface tension in aqueous solution, strong solubilization, good emulsifying ability and cleaning and decontamination effect. In addition, non-ionic surfactants have a high tolerance to electrolytes, and can be used in a wide range of pH values to be compatible with various types of surfactants
Surfactants are not only used in daily chemical products, but also in all aspects of daily life, such as paint, glue, pesticides and so on. Knowing some knowledge about surface activity can help us keep our eyes open when choosing related products, taking into account the effectiveness and health to the greatest extent