Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Foaming agents
Antwain
National Hazard
****




Posts: 252
Registered: 21-7-2007
Location: Australia
Member Is Offline

Mood: Supersaturated

[*] posted on 1-10-2007 at 21:52
Foaming agents


Ok, I UTFSE and couldn't find anything about this.

What is a good foaming agent, perhaps the word I am looking for is surfactant, I'm not sure. What I want to know is:

By weight, what substance(s) will cause the largest amount of persisting air-bubbles when used in an aqueous solution and agitated/aerated.

I remember noticing when I was a little child that any kind of dish or clothes washing detergent was not nearly as effective for bubble making as commercial bubble making solutions or bubble bath. Having looked through the ingredients in the bottles a few years back, I still couldn't see some magical TYPE of chemical. They all seem to be a concoction of fatty acids, esters, glycerine and so on. What do you guys know of this? ;)
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 1-10-2007 at 23:11


Surfactants include wetting agents and foam forming agents, not all surfactants are good at forming foams and some are designed not too.

When making bubbles is the goal, various surface active agents like fatty acid soaps or alkyl sulfates are mixed with foam stabilisers, typically c14 to c20 alcohols made from the corresponding fatty acids and/or polyethylene glycohol/oxide, and glycols or glycerol to slow down the thinning of the bubble wall from evaporation.

Other foam formers use proteins, natural or modified, or fluorocarbons, which give resistance to polar organic solvents.

I've never seen rankings of the effectiveness of various agents, but I'm sure they exist. As most of these seem to be mixtures, and there are a wide range of applications, there may be no comprehensive list but rather evaluations targeted at particular applications such as fire fight foams, disinfectant foams, ore beneficiation , and so on.
View user's profile View All Posts By User
DrP
International Hazard
*****




Posts: 625
Registered: 28-9-2005
Member Is Offline

Mood: exothermic

[*] posted on 2-10-2007 at 00:21


Quote:
Originally posted by not_important

I've never seen rankings of the effectiveness of various agents, but I'm sure they exist. As most of these seem to be mixtures, and there are a wide range of applications, there may be no comprehensive list but rather evaluations targeted at particular applications .


I don't think there are tables - it depends on the application as to what surfactant is best as not_important has said.

For bubbles - good old washing up liquid is pretty effective.

What are you wanting it for?
View user's profile View All Posts By User
Antwain
National Hazard
****




Posts: 252
Registered: 21-7-2007
Location: Australia
Member Is Offline

Mood: Supersaturated

[*] posted on 2-10-2007 at 02:02


To be honest I was just curious. I was also thinking about a few years ago when a bunch of PhD's somehow turned the water feature outside the research school of chemistry into a huge foam pool, overflowing a meter above the edge and pouring out onto the path (we're talking over 100 cubic meters of foam here, easily). I believe that they only used only about one liter of *something* and I was wondering what could do that. If they were still around I could ask them, but I think one guy got kicked out and the others have gone now :P

Since I don't want to get booted myself this is hypothetical, but interesting still :D

Also, the other day I saw pictures of what happens when a fire suppression system wont shut off in an airplane hanger. God only knows how much foam there was there but I doubt that they had a kiloton of foam generating chemical on hand, so whatever it was must have been potent stuff.
View user's profile View All Posts By User
Tacho
International Hazard
*****




Posts: 582
Registered: 5-12-2003
Member Is Offline

Mood: No Mood

[*] posted on 2-10-2007 at 08:09


I too would like to know more about foaming agents. I can see many uses for them, like aerated (light) concrete or aerated resins.

Long ago I saw this post in the usenet, and the dibromooleic acid is something I would like to try:

"Alan \"Uncle Al\" Schwartz
10 nov 1996, 05:00
sci.chem
Assunto: Re: Any Giant Bubble Recipes?


tr...@central.co.nz (Bruce Levett) wrote:
> Has anybody got a good recipe for those HUGE detergent bubbles?
>I've tried:
> liquid detergent, washing soda (as a water softener), glycerol,
>water mixtures in varying proportions but without much success.
>Two that I've read are amazingly different compositions.


It helps if you have a giant bubble wand, preferably felt-covered to feed
liquid to the growing bubble). A terrycloth sling is pretty good.

The obvious guess is Dawn dishwashing liquid. It works for everything
else!


You might also try the sodium salt of dibromooleic acid (add bromine to
the acid cool and dark, then neutralize with NaOH - not for the amateur)
with 20% glycerine in water. I understand the resulting bubbles are
remarkably reluctant to break.


--
Alan "Uncle Al" Schwartz
Uncle...@ix.netcom.com ("zero" before @)
http://www.ultra.net.au/~wisby/uncleal.htm (lots of + new)
(Toxic URL! Unsafe for children, Democrats, and most mammals)
"Quis custodiet ipsos custodes?" The Net! "
View user's profile View All Posts By User
Slimz
Hazard to Others
***




Posts: 123
Registered: 18-9-2007
Member Is Offline

Mood: Inquisitive

[*] posted on 2-10-2007 at 08:53


http://steelturman.typepad.com/photos/uncategorized/suds_fou...



Johnny was a chemist’s son, but now he is no more. What Johnny thought was H2O was H2SO4
View user's profile View All Posts By User
Antwain
National Hazard
****




Posts: 252
Registered: 21-7-2007
Location: Australia
Member Is Offline

Mood: Supersaturated

[*] posted on 2-10-2007 at 13:38


Pretty much like the pic, only bigger. Unfortunately the powers that be turned the fountain at my uni off to stop the foaming, otherwise it could have been more exciting. I heard an urban legend which like all urban legends may or may not be true. Supposedly some guy went on a holiday and some youths :P poured 10s of kilos of laundry detergent into his pool filter/pump . The police phoned him several days later because a neighbor had called the police because foam was flowing over the fence into her yard. I cant see where the frothing would come from, but hey, its a funny story.

Hmm, where to get oleic acid from. (and flame away, i will UTFSE *when* I have posted :P )

Well, apparently, if you don't mind 40% not oleic acid then peanut oil is the answer!
http://www.sciencemadness.org/talk/viewthread.php?tid=8076&a...

Also If I was going to foam a fountain, i'd hit this.... its about 10min drive from my house :D

http://upload.wikimedia.org/wikipedia/commons/thumb/7/73/Cap...

[Edited on 3-10-2007 by Antwain]
View user's profile View All Posts By User
chemkid
National Hazard
****




Posts: 269
Registered: 5-4-2007
Location: Suburban Hell
Member Is Offline

Mood: polarized

[*] posted on 2-10-2007 at 13:51


sodium laureth sulfate. Used all the time in hair products etc.

Chemkid

[Edited on 2-10-2007 by chemkid]




View user's profile View All Posts By User

  Go To Top