Surfactants are a category of chemical compounds that are used in lowering the surface tension (or interfacial tension) between different compounds, such as two liquids or between a gas and a liquid, or it can also be between a liquid and a solid. Surfactants are categorised as organic compounds and are amphiphilic in nature. It basically means that they contain both hydrophobic and hydrophilic groups.
Surfactants consist of hydrophobic (water-hating) and hydrophilic (water-loving) groups.
The molecules of surfactant are adsorbed by the oil, and hence they are removed from the surface.
The molecules of surfactant surround the oil after it has been removed and prevent it from depositing again.
Types of Surfactants
There are several types of surfactants
A-Anionic surfactants
These have a negatively charged end of the molecule that gives it the hydrophilic part of the molecule. These negatively charged parts of the molecules are usually sulfonates, sulfates, or carboxylates that are usually neutralized by positively charged metal cations such as sodium or potassium.Such as SLES,SLS,LABSA,AOS,LAS
B-Cationic
If the head group (hydrophilic end) has a positive charge, it is called cationic. Many cationic surfactants have bacteriacidal or other sanitizing properties that are useful in creating disinfectants that leave a cationic disinfectant film on the surface.Such as CTAC,CTAB
C-Amphoteric surfactants
Those surfactants that change their charge with pH. They can be anionic, nonionic, or cationic depending on pH. Such as Cocamidopropy Betaine/CAB,CAO
D-Nonionic
These are surfactants that have no ions. They derive their polarity from having an oxygen–rich portion of the molecule at one end and a large organic molecule at the other end. Such as APG,CMEA
Uses of Surfactants:
Surfactants today are found in many products that we use today. They are found in detergents, wetting agents, foaming agents, emulsifiers and dispersants. Surfactants are one of the important components in detergents that help to eliminate dirt from clothes, skin and household utensils, mainly in bathrooms and kitchens. Besides, they are extensively used in industries.
Used in agrochemical formulations such as herbicides (some), insecticides, biocides (sanitisers), and spermicides.
Used in personal care products such as cosmetics, shampoos, shower gel, hair conditioners, and toothpaste.
Surfactants are used in firefighting and pipelines (liquid drag-reducing agents). Alkali surfactant polymers are also used to mobilise oil in oil wells.
Surfactants are sometimes added to car engine lubricants which greatly help to keep particles from sticking to engine parts.
Surfactants are also commonly used in corrosion inhibition in ore flotation.
They are also used in corrosion inhibition, to promote oil flow in porous rocks, and to produce aerosols.
You can contact HOO CHEMTEC to know more about the applications of surfactants in daily life and manufacturing processes in various industries.
