On 8/2/2017 5:53 PM, Frank wrote:
On 8/2/2017 5:40 PM, Muggles wrote:
On 8/2/2017 12:55 AM, wrote:
On Tue, 1 Aug 2017 22:45:11 -0500, Muggles
wrote:

On 8/1/2017 10:33 PM, wrote:
On Tue, 1 Aug 2017 22:17:25 -0500, Muggles
wrote:

On 7/31/2017 1:18 PM, Frank wrote:

Could shop for his needs he

http://www.kolene.com/salt-bath-equi...aning-systems/

Frank... I have a chemistry question related to detergent/soap
suds and
oil/grease.

I've noticed that many soaps will bubble and lather up nicely but
when
it hits the oil or grease that the lather and bubbles disappear.
Also,
if oil or grease is present that soap doesn't want to bubble up.

The reason I ask is I see the same thing happen when I use liquid
bath
soap and bath oil. If I haven't used any bath oil in the tub, the
liquid bath soap will lather and bubble up nicely, but if I used bath
oil before using the soap, the soap won't lather up at all.

Is the oil breaking down the bath soap or vice versa? What causes
the
soap to not lather up if oil is present in the water?

Soap and oil form an emulsion. That is not like either of them but it
does make the oil more mobile so it will go down the train easier.


OK I understand what you're saying.

So, why doesn't the soap bubble/lather up when oil is present in the
water? I thought the soap lather was supposed to break down the oil,
but it seems to be the other way around.

If I have soap bubbles in the water, they will totally disappear if I
add bath oil to the water.

I'm just curious as to what is chemically happening ... why does the
oil
prevent the soap from foaming up?

It isn't soap anymore it is a soap/oil emulsion and the soap will not
support the bubbles. You see the same thing in dish water once oil
builds up it to the point that it has overwhelmed the soap (or
detergent). It is actually a good thing because the oil is trapped in
that emulsion, the object of the exercise. If there is sufficient soap
in the water, it will carry that oil down the drain and off to the
sewer plant.
You see it work the opposite way if there is an oil slick on the water
around your boat and you squirt some detergent in the water. The oil
is still there but the slick is gone. (a trick people do to avoid
getting busted by the enviro cops)


Thanks for the explanation!


Did not see this part of the thread until now and explanation is correct.

A soap is the carboxylate salt of a fatty acid and detergents are the
same except they are sulfonate salts of long chain fatty type materials.
The salt end of the molecule is attracted to water and the fatty end to
the oil. Emulsion is a droplet of oil surrounded by the soap suspended
in the water. There are ways to break emulsions like freezing, making
acidic or salting out. A lot of products are sold as emulsions which is
why you should not freeze things like paints as you might break the
emulsion and ruin them.

Soaps do not function as well in hard water as the calcium ion causes
precipitation. Detergents can still work in hard water.

Thanks! I understand what you just told me.

What I'm not sure is, what causes the soap to not foam up in the
presence of oil?


--
Maggie