For a long time, water has been considered the main cleaning agent for humans. However, its exclusive use has proven to be ineffective in eliminating certain types of residues, such as oils or fats. Water alone does not wet the surfaces it comes into contact with well, due to its high surface tension. Thus, it became necessary to develop new ingredients that, when added to water, reduce its surface tension and promote greater interaction with the surfaces to be cleaned. Among these ingredients, the main ones are soaps and surfactants, whose development has allowed us to evolve cleaning and personal hygiene practices.
Soap and Detergents
Detergency is the ability to remove undesirable material (dirt) from a surface, whether solid, liquid, or gas. Among the substances with this characteristic, soaps have been in use the longest, and their main structural feature is having a hydrophilic end (which is attracted to water) and a long hydrophobic carbon chain, meaning it does not dissolve in water and is attracted to dirt.
In addition to soaps, their synthetic substitutes, generically called surfactants, are also used as detergents. Similarly, these compounds act by reducing the surface tension of water, allowing oils and fats to be emulsified and easily removed from surfaces.
Other Cleaning Agents for Skin and Hair – and in Other Areas
Cleaning formulations for body and hair, such as soaps and shampoos, generally consist of soaps or surfactant systems in an aqueous medium. These products promote the removal of oily materials, proteins, soot, and particulates from the skin, hair, and scalp, through the formation of micellar aggregates, reducing the adhesion between the "dirt" and these surfaces.
Other examples of cleaning processes used, on a smaller scale, for personal care are powder shampoos that, instead of cleaning through contact with water, absorb the oiliness from the strands, leaving them looking clean. There are also products that contain abrasive particles, such as silica, which remove dead skin cells.
Considering cleaning in a broader context, we can mention other processes, such as: the use of ultrasound, solvents for dry cleaning, the application of alkaline products, such as caustic soda, sanitizing agents like sodium hypochlorite, the use of microorganisms, and even skin cleaning with the help of fish or the use of ceramics in laundry cleaning. There are also processes that do not clean but alter the surface of materials, preventing dirt adhesion, such as fabric waterproofers.
Could any of these processes be applied to the cosmetic industry? Do you know of other methods that can be used in personal hygiene?
Read more about the Challenge and submit your idea by November 25 to participate in the “Cleaning Technologies for Personal Care” Challenge!
