A Química dos Detergentes


Uploaded by quimicadascoisas on 12.03.2012

Transcript:
THE CHEMISTRY OF THINGS
Chemistry is everywhere!
It's part of our every days lives, most of the times without us even noticing it.
Today in the Chemistry of Things we talk about...
detergents.
It may seem like detergents have been part of our lives forever,
but the truth is that the first detergents only began to be sold
less than 90 years ago.
In 1920, washing machines were still running on soap flakes
and with many problems:
poor efficiency with hard water,
forming of dirt deposits
and damage to coloured clothing.
Detergents are long molecules
with a tail that mixes well with fat
and a head that mixes well with water.
The detergent molecules surround the fat particles,
turning the head that "likes water" to the outside,
thus allowing stains to be captured and dissolved.
Detergents have been subject of constant improvements
to increase their cleaning power,
to better protect coloured clothing
and to have a lower environmental impact.
A detergent with "gluttons" was famous in the past.
Do you still remember it?
It was a detergent mixed with enzymes,
whose role was to attack the protein, fats and carbohydrates chains,
breaking them into more soluble pieces,
thus helping to remove food stains.
Another curious innovation was the addition of "optical whiteners"
which are chemicals that don't actually contribute to cleaning
but attach themselves to fabrics and make them look whiter
and are responsible for detergents that "wash whiter than white".
More recently we have several detergents on the market
that use oxygen to oxidize the dirt.
Oxidation causes discoloration of the pigments
common in fruits and other foods
and also aids solubility.
But the future is in environment and clothes friendly detergents.
Research in this area is still very active
and the results will soon be inside your washing machine.
To know more about the chemistry detergents
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