Modern Detergents

Modern detergents must be capable of a lot. They have to remove dirt, protect the fabric and the washing machine, soften the water, and keep white fabrics pristine.

Ionic surfactants dissolve grease very well. There are non-ionic (neutral) and anionic (negatively charged) surfactants. In technical language they are called synthetic tensids. In addition to the synthetic tensids, common soaps are also added to the detergents. The problem with soaps is that they flocculate in hard water. The addition of water softeners (NTA, zeolithe, citrate) softens the water. If there are blood, protein or cacao stains on the fabric, only enzymes can help. They only work between 30 and 60 °C. Stains from fruits, tea or red wine can only be bleached. Thus they are not really removed, but become invisible. Formerly, fruit, tea and red wine stains were blanched in the sun. White laundry often goes yellow when washed. If an optical brightener is added, the laundry absorbs UV light. As a result, the laundry looks bright white.

Experiment:

We need: water, 3 pieces of gelatine, washing powder

Experiment: Gelatine (1.66 g) was dissolved (soaked and heated) in 200 ml water and distributed into 5 glasses.

Washing powder was added to four of the glasses. Afterwards, all the glasses were refrigerated.

Without washing powder, the content of the beaker became solid

The liquid in the glasses with gelatine and washing powder did not become solid.

We grated red and blue chalk and stirred it into one of the beakers. A violet liquid was the result. Afterwards, we added acetic acid.

Result: Coloured gelatine stuck to the stirring rod and some remains of colour stuck to the beaker wall.