The benzosulfate bit is happy to swim about loosely bonding with water, while the dodecane chain hates water. If these molecules bump into something they feel better about such as, say a bit of fat from milk on your shirt , they reach a compromise, with the dodecyl chain attaching to the fat, and the benzosulfate chain happily hanging out with the water.
As things slosh about, the bit of fat will attract the dodecyl chain of more detergent molecules, covering it. The benzosulfate bit is still trying to hang onto the water, though.
Eventually, the two reach a compromise by creating a small globe around the bit of fat or oil, which then floats off the shirt into the water. When it is like this, the dodecyl chains are happily hanging onto the fat and chilling with their neighbor dodecyl chains, and the benzosulfate is hanging with the surrounding water. And that's how the stains are lifted from your shirt: they are surrounded and freed by these enclosing globes of detergent.
These enclosed globes usually called micelles are very small: usually composed of just a few hundred molecules in each globe, floating in the water.
Chemists call this type of solution a colloid, because the oils aren't really dissolved in the water: they are instead held in thee microscopic micelles. To you, it looks like the stains are dissolved in the water, and when the water is drained, it takes the stains with it down the drain.
That, of course, is only part of the story. These surfactants form about 30 to 40 percent of the weight of the detergent, and they are accompanied by chemicals such as enzymes and others that break stains down and help the process run quickly.
We'll look at these in a future column, and look at how temperature and agitation affects the chemistry of cleaning your socks. One interesting bit of historical grossness: the Romans didn't use detergents, although soaps were known to them. Instead, they used urine. Be sure that soil is actually being removed and not just covered up with perfume.
Biotechnology could cut C02 sharply, help build green economy. World Wildlife Fund. Svedman, Cecilia, et al. Current Treatment Options in Allergy , vol. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content.
Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products.
List of Partners vendors. Sensitive Skin? Featured Video. Article Sources. The Spruce uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. World Wildlife Fund Svedman, Cecilia, et al. Read More. The word surfactant stems from the combination of words "surface-active agents. The tail of a surfactant molecule is hydrophobic, or not attracted to water.
What the hydrophobic end is attracted to is grease and dirt. The head of the surfactant molecule, on the other hand, is hydrophilic -- it's attracted to water [source: Silberberg ]. So when a greasy piece of clothing is immersed in water with detergents containing surfactant, the tail of the surfactant molecules attach to the grease, and the head end of the molecule is attracted to the water.
When the washing machine agitates the clothes, the molecules form tiny spheres, which stay suspended in the water and are rinsed away when the water is drained. Therefore, the prime benefit of surfactants is their ability to draw grime out of clothing while making sure it doesn't return to the fabrics. Essentially, there are four main types of surfactants, with the first three used the most in laundry detergents, and their actions depend on their interactions with ions.
Ions are charged particles due to the gain or loss of electrons. Researchers at Wright State University examined the extent to which mites and mite allergens were removed when washing clothes in water alone and with detergents.
Interestingly, they found that both methods were equally effective in removing mite allergens. The researchers suggest that washing in water alone is equally effective as washing with detergent because allergens and mites are water soluble, so contact with water removes them [source: Arlian ].
Although surfactants are at the heart of laundry detergent's ability to clean fabrics, other ingredients can help detergents clean better, brighten clothes or smell better. As described previously, some types of surfactants typically do not work well in hard water due to the excess positive ions present. Additives called builders can help detergents to work better under hard water conditions. This allows the surfactants, especially anionic surfactants, to bind to more grime, rather than the positively charged ions in the wash water.
Builders also are bases, so they work to neutralize acid and can help disrupt chemical bonds. Another benefit of adding builders to laundry detergents is that manufacturers can use less surfactant, since the builders make the surfactant more efficient. Detergents can also include components that make clothes whiter or brighter. The most common whitening agents are bleaches. Bleaches contain peroxides, which can oxidize fabrics [source: EPA ].
Fluorescent whiteners and brighteners are also added to some laundry detergents because they minimize the yellowing of fabrics. These additives work by absorbing ultraviolet light and emitting back visible blue light, which can mask the yellow that may make colors appear faded and whites appear dingy. Enzymes are naturally occurring biologic agents present in many detergents in varying concentrations.
These enzymes are typically classified into the following categories and are similar to the enzymes used by your body to digest food:. These enzymes help break down food particles that are present on clothing by catalyzing, or speeding up, the decomposition process.
A point to consider is that enzymes are biological products that can break down over time. Therefore, detergents can also contain enzyme stabilizers, which protect the enzymes and help them function. Some other components include fragrance and coloring, which give laundry detergents their distinctive scents and appearance. Detergents sometimes contain trace amounts of dye, which is not enough to dye your actual clothing.
However, on top of making your laundry detergent more visually appealing, dyes can show you when there is still detergent left on your clothes after the wash cycle. Lastly, fillers help dilute and distribute the active ingredients to their proper dosages. Powder and liquid detergents use different fillers. The major filler in powder detergents is sodium sulphate, which provides the granular powdery texture. The primary filler in liquid detergents is water.
In the next page, we will examine some more similarities and differences between powder and liquid detergents. Soaps and detergents both act as cleansers. In fact, prior to the development of detergents, people used lye-based soaps to wash clothes. However, lye laundry soap could lead to dull colors, graying whites and rings of soap scum in washing machines. Though soap is a surfactant, the major difference between it and detergent is that soaps don't contain many of the additional components such as builders, enzymes, whiteners and brighteners that make laundry detergent better at cleaning clothes.
Laundry detergent manufacturers have come a long way since the first box of Tide was produced more than 60 years ago.
Currently, the two main types of laundry detergent are powders and liquids. Use precise geolocation data. Select personalised content. Create a personalised content profile.
Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights. Measure content performance. Develop and improve products. List of Partners vendors. Share Flipboard Email. Anne Marie Helmenstine, Ph.
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