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Main article: detergent
Many kinds of molecules and ions can serve as high-efficiency surfactants.
They are often classified according to the charge of the molecule or
ion, the three main classes being anionic, neutral, and cationic
detergents. Anionic detergents are most commonly encountered for
domestic laundry detergents. Detergents are ions or molecules that
contain both polar and nonpolar components. The polar component allows
the detergent to dissolve in the water, whereas the nonpolar portion
solubilizes greasy ("hydrophobic") materials that are the usual target
of the cleaning process. An estimated 6 billion kilograms of detergents
are produced annually for domestic markets.[5]
[edit] Components
Modern detergent formulations - the entire product vs just the surfactant - contain several components. Three main ingredients are builders (50% by weight, approximately), the alkylbenzenesulfonate surfactant (15%), and bleaches (7%).[5][edit] Builders
Builders are water softeners. These chemical compounds are agents that remove calcium ions by complexation or precipitation. Typical builders are sodium carbonate, complexation agents, soap, and zeolites. They function by sequestering or precipitating the problematic ions. One of the most common builders is sodium triphosphate, which is used on very large scale for this application.[edit] Bleach
Main article: Bleach
The main targets of bleaches are of vegetable origin and include chlorophyll, anthocyanin dyes, tannins, humic acids, and carotenoid pigments. Most bleaches in laundry detergents are oxidizers, e.g., sodium perborate or sodium hypochlorite,
In addition, other agents are added as "bleach activators", to enhance
the effectiveness of the bleaching agent; a popular one is tetraacetylethylenediamine.[edit] Enzymes
Main article: Biological detergent
Many laundry detergents contain enzymes.
The amounts of enzyme can be up to about 2% by weight of the product.
These agents are required to degrade recalcitrant stains composed of proteins, fats, or carbohydrates. Each type of stain requires a different type of enzyme, i.e., protease for proteins, lipases for greases, and amylases for carbohydrates.[edit] Other ingredients
Many other ingredients are added depending on the specific application. Such additives modify the foaming properties of the product by either stabilizing or counteracting foam. Other ingredients increase or decrease the viscosity of the solution, or solubilize other ingredients. Corrosion inhibitors counteract damage to washing equipment. "Dye transfer inhibitors" prevent dyes from one article from colouring other items. "Antiredeposition agents" are used to prevent fine soil particles from reattaching to the product being cleaned. Carboxymethyl cellulose is used for this purpose.[5]A number of ingredients affect aesthetic properties of the item to be cleaned or the detergent itself before or during use. These agents include optical brighteners, fabric softeners, and colourants. A variety of perfumes are also components of modern detergents, provided that they are compatible with the other components and do not affect the colour of the cleaned item. The perfumes are typically a mixture of many compounds, a popular component being cyclohexyl salicylate, which is related to oil of wintergreen.[5]