"Andy Hall" wrote in message
...
On 2007-10-10 11:52:54 +0100, (Andrew Gabriel)
said:

In article ,
Andy Hall writes:
On 2007-10-09 23:37:31 +0100, "Clive George"
said:

"Andy Hall" wrote in message
...

A recently purchased pack of dishwasher cleaner claimed to have X% of
non ionic surfactant which all sounds very innocent and like the
instruction book for a 1960s girl's chemistry set.

Reading in more detail and looking at the MSDS revealed that it was
our
old friend, NaOH. No other ingredients were mentioned.

That'll be what does some of the work, but there will be a non ionic
surfactant as well, since NaOH doesn't fit that definition at all.

cheers,
clive

I see.

What things fall within that definitiion?

A wetting agent, like a detergent (except they are more
commonly ionic surfactants). It's a long time ago since
I knew this, but IIRC ionic surfacants tend to foam
easily as they skin over water one molecule thick with
the charged end of the molecule in the water and the
uncharged end sticking out, aiding bubble formation.
This is a bad thing in a dishwasher as anyone who's
tried using regular washing up liquid in one will tell
you. Non-ionic surfactants don't do that.

The surfacant ensures the food can be quickly wetted by
the caustic soda, so it can quickly get to work on it.
The surfacant also has cleaning properties in that it
can break dirt down into small particles and surround it,
making it appear to be soluable when in fact it isn't by
itself.


OK.

By dishwasher cleaner here I meant the product that can be put in
periodically to clean the machine itself.

Makes no difference. You still don't want a foaming surfactant. You could
well have more NaOH to attack the stubborn stuff a bit more, but that still
doesn't make it a) non-ionic b) a surfactant, or c) miscible with
oil/grease. You still need the surfactant as Andrew said above.

cheers,
clive