Application of surfactants in traditional fields
Surfactants have a series of superior properties such as wetting, emulsifying, dispersing, solubilizing, foaming and defoaming, penetrating, washing, antistatic, bactericidal, etc. They have a wide range of applications in traditional civil fields such as detergents, cosmetics, personal hygiene products, etc., as well as in industrial and technological fields such as textiles, food, medicine and pesticides, paints and coatings, construction, mineral flotation, energy, pulp and paper, tanning and other industries.
In recent years, the development of high and new technology is changing day by day, and surfactants with their unique functions in nanotechnology, environmental protection; new materials, life sciences and other high-tech fields become indispensable products.
Application principle of surfactants in detergents
Detergents are daily-use chemicals that are formulated from surfactants, detergents and auxiliaries to remove dirt from the surface of objects and achieve the purpose of cleaning and cleaning.
Currently, detergents commonly used in the civil field mainly include laundry detergent and fabric softener for cleaning clothes, detergent and dishwashing liquid for cleaning tableware, fruits and vegetables, and toilet bowl cleaner for removing grease in the kitchen and toilet cleaning.
Surfactant is the main component of detergent, so detergent and surfactant, in addition to excellent washing and decontamination ability, but also has a good wetting, foaming, emulsification, dispersion, solubilization ability.
Early detergents often used a single surfactant, such as sodium alkylbenzene sulfonate. However, nowadays detergents generally use complex surfactants, such as anionic/anionic complex or anionic/nonionic complex.
Due to the synergistic effect between mixed surfactants, sometimes the detergents have good detergent detergency at lower surfactant content.
The process of detergent decontamination and the related mechanism have been briefly introduced. The core of the process is to separate the dirt from the surface of the object to be cleaned through the physicochemical action of surfactants and the mechanical and aqueous action, and to be carried away by the aqueous flow.
The adsorption of the surfactant on the surface of the dirt and the substrate is the key, and this leads to the following series of basic actions.
(1) Penetration and wetting
During the washing process, surfactant molecules are able to adsorb onto the surface of the article and dirt, reducing the interfacial tension between the medium (generally water) and the surface of the article, as well as between the medium and the surface of the dirt, so that the medium is able to penetrate between the article and the surface of the dirt and penetrate into the interior of the article. This effect is called the wetting penetration effect of the detergent.
The wetting of the washing liquid on the washing article is a prerequisite for washing, if the washing liquid can not wet the article well, there is no good washing and decontamination effect.
The wetting penetration effect of the detergent solution not only reduces the attraction between the surface of the article and the surface of the dirt, but also reduces the attraction between the particles of the dirt, and when appropriate external force, the dirt can be broken into small particles and dispersed in the medium.
