Gravity's Effects on Aqueous Foams - Discussion & Experiments

[Telmerk]

Dear all,

What do you think, how the gravity effects on the structure of aqueous foams?
I' ve just made a series of http://www.admatis.com" , Bremen, Germany.
There are a lot of experiments available in micro-g, using parabolic flight missions.

I would be happy to discuss with you the recent results and the open questions!

 

[Danger]

I know nothing about such stuff, and unfortunately can't understand the first link, but it looks fascinating. I'll certainly monitor this thread.

 

[quinn]

I would guess that gravity plays only a small role in foam formation, because surface tension is far greater of a force in this situtation and the mass of the foam surfaces is small.

I was surmise that gravity only has a settling effect.

 

[Mk]

I know nothing about such stuff, and unfortunately can't understand the first link, but it looks fascinating. I'll certainly monitor this thread.

In case you didn't find the English versions, it's here. Not the whole site is also in English.

 

[Telmerk]

Sorry

Dear PhysicsForumers,

I am sorry that I answer so late. I think quinn is right, we can expect that gravity level has a small effect (but it do have some!) on foam evolution because the effect of gravity is proportional to the mass, and foams have small mass.
Here is a little article about foams, (sorry for my bad English. ) see the attachment. It will appear on the website (with pictures) I linked in the http://www.admatis.com" . For starting, one of the best article about the physics of foams is the so called Making, Measuring and Modelling Foams, by Denis Weairie and Stefan Hutzler, Europhysics News, May/June 1999.

A lot of experiments has been carried out in micro-g, to obstruct the gravity-driven drainage, and to achieve stable foam structures even from materials that are unstable on Earth. we tried out, what happens in macro-g. We could not measure the cell wall thickness inside the foam, we only monitored the foam heights. We expected that with increasing gravity levels it is more difficult to create foams.
It is true. See the the plot below, made from raw data. I am looking forward to evaluate all of our measurements and to clarify the effect of macro-g.
Hopefully, there will be detailed results within a few months..

Kind regards,
T, the Magician

 

[Telmerk]

Some new material

Hi, dear Forumers and Foamers,

There is a new publication about the above mentioned foaming experiments at the http://www.zarm.uni-bremen.de" home page. Check it out, if you have some free time! Follow: Facilities/Centrifuge/Application/Scientific Applications

Regards,

T.