How do detergents clean

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. For the aristocracy of Rome, the best way of getting your wollen toga washed after it got grubby with a few weeks wear was to give it to the Fullo , the washer and scourer of cloth and linen.

This dedicated class of laundry workers used urine and other chemicals to remove stains. To obtain the urine, they placed large pots on street corners and encouraged passers by to relive themselves.

The clothes were then washed in this mixture, which was agitated by young boys treading on it for hours. The fabric was then scoured in fuller's earth and dried. So, the next time you are watching Spartacus or a particularly gripping performance of Julius Caesar, consider that the hero's outfit would have been washed clean of the blood stains afterwards in urine, and that the streets these heroes trod stank of urine. Believe me, it gives you a whole new perspective on history, and how utterly icky most if it was.

Be respectful, keep it civil and stay on topic. Thus a neutral particle can become charged when detergent molecules attach to it. To explore diffusiophoresis in fabric cleaning, Shin and his colleagues ran experiments in a microfluidic channel connected to a series of micrometer-wide, dead-end pores. When fluid flowed through the main channel, there was little flow into the pores, mimicking the situation of stagnant cores in fabrics.

The team allowed dirt—represented by micrometer-sized, fluorescent, polystyrene particles—to accumulate inside the pores. They then mixed in a detergent, sodium dodecyl sulfate, which produces a negatively charged surfactant ion in solution. As a control test, the team flushed the channel with detergent-filled water. This flow was unable to dislodge particles in the pores, and as the concentration remained more or less uniform, there was no help from diffusiophoresis.

That changed when the team rinsed with fresh water. The rinse flushed away most of the detergent, except deep in the pores where the surfactant ions remained concentrated. The resulting solute gradient created an electric field that helped to draw surfactant-covered particles out of the pores. Under the influence of this diffusiophoresis, the pores nearly emptied out after 10 minutes of rinsing see first video. The team also conducted model laundry experiments.

The results showed that, after soaking a stained cotton fabric with detergent, a fresh water rinse cleans faster and more thoroughly than a rinse with detergent-filled water see second video.

Based on these findings, the researchers make several recommendations for optimizing the cleaning process. The hydrophilic end of the same molecule means that one end of the molecule will be attracted to water, while the other side is binding to oil.

Neither detergents nor soaps accomplish anything except binding to the soil until some mechanical energy or agitation is added into the equation. Swishing the soapy water around allows the soap or detergent to pull the grime away from clothes or dishes and into the larger pool of rinse water. Rinsing washes the detergent and soil away. Warm or hot water melts fats and oils so that it is easier for the soap or detergent to dissolve the soil and pull it away into the rinse water.

Detergents are similar to soap, but they are less likely to form films soap scum and are not as affected by the presence of minerals in the water hard water. Modern detergents may be made from petrochemicals or from oleochemicals derived from plants and animals.

Alkalis and oxidizing agents are also chemicals found in detergents. Here's a look at the functions these molecules serve:. 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.