Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: joedeluco on 12/11/2009 09:30:02
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Joe DeLuco asked the Naked Scientists:
What is the difference between the soap we use to hand-wash dishes and the soap we put in a dishwashing machine?
The latter does not have any suds yet works very well. Are the two similar in how they work? And do more suds really mean better cleaning as the advertisers often imply?
What do you think?
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A sort of related question is why does dropping the cake of soap in the bath make all the bubble-bath induced bubbles disappear?
What's causing this?
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IIRC
The "soaps" used in dishwashers and washing machines are not really soaps but detergents that are made from chemicals which do not lather much or produce many bubbles that last. Soaps however, hand soap or liquid soap, is made from a process using oils and caustic soda which lathers a lot.
In an enclosed washing machine low lather detergent is normally used as having too many bubbles can reduce the efficacy of the cleaning process.
When the two get mixed the chemical reaction from the soap causes the bubbles produced by the detergent to collapse. That is what I think is happening to the bubble bath bubbles (detergent) when some soap is added to the water. The exact chemical reaction I'm not sure of.
# edited as I wrote it the wrong way round..