Discussion:
carbon dioxide filled latex balloons
(too old to reply)
sydscience
2009-02-08 19:35:00 UTC
Permalink
My daughter did her science experiment measuring the deflation rates
of latex balloons filled with helium, carbon dioxide and compressed
air. The carbon dioxide balloons deflated fastest but we have no idea
why. Does anyone know the reason that carbon dioxide filled balloons
deflate faster than helium or compressed air? Many thanks.
N:dlzc D:aol T:com (dlzc)
2009-02-08 20:12:49 UTC
Permalink
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
These folks don't either:
http://www.answerbag.com/q_view/734234
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did you decide
rates of deflaton?

David A. Smith
sydscience
2009-02-08 20:37:52 UTC
Permalink
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air.  The carbon dioxide balloons
deflated fastest but we have no idea why.
These folks don't either:http://www.answerbag.com/q_view/734234
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of.  How did you decide
rates of deflaton?
David A. Smith
We measured the circumference of the balloons every 30 minutes.
N:dlzc D:aol T:com (dlzc)
2009-02-08 21:18:31 UTC
Permalink
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?

David A. Smith
Bruce Sinclair
2009-02-09 00:22:58 UTC
Permalink
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2. Example
.. you inflate your car tyres with air. Tyre manufacturers recomend
nitrogen. After a while of filling them with air, you pretty much have 100 %
N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ? Perhaps it
'dissolves' in the rubber then permeates ?

I'm sure someone can confirm/deny :)
N:dlzc D:aol T:com (dlzc)
2009-02-09 00:33:49 UTC
Permalink
Dear Bruce Sinclair:

"Bruce Sinclair"
T:com \(dlzc\)"
On Feb 8, 12:12 pm, "N:dlzc D:aol T:com \(dlzc\)"
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium,
carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and
cooling
added to an *apparent* deflation. How many balloon of each
gas?
Most rubbers (and many plastics IIRC ?) are more permeable
to CO2. Example .. you inflate your car tyres with air. Tyre
manufacturers recomend nitrogen.
... as a boondoggle to get more money, in many cases.
After a while of filling them with air, you pretty much have
100 % N. :)
Why ? The CO2 and O (slower I think ?) escapes faster.
Why ?
The oxygen oxidizes stuff on the inside, that is why the oxygen
disappears from inside tires.
Perhaps it 'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
http://books.google.com/books?id=IhDFIj-PoucC&pg=PA48&lpg=PA48&dq=balloon+latex+diffuse+rapidly+co2+OR+carbon-dioxide&source=web&ots=_Ib_fjHAbh&sig=jf7hwFKOF9x_rx89W2c5UAZ3BDw&hl=en&ei=UXePSaPrOYzQMcORoZEL&sa=X&oi=book_result&resnum=5&ct=result#PPA49,M1
... bottom of page 48 and bottom of page 49. Says it difuses at
a rate of 0.5 cc / minute through a latex pulmonary artery
catheter.
Seems to be a known behavior, but I have found no "why" for the
OP's question. Partial pressures won't be the answer, since the
percentage of CO2 in the atmosphere is much higher than is that
of helium... and its average speed will be lower due to its
molecular mass.

David A. Smith
Craig
2009-02-09 01:36:15 UTC
Permalink
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide.  Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation.  How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2. Example
.. you inflate your car tyres with air. Tyre manufacturers recomend
nitrogen. After a while of filling them with air, you pretty much have 100 %
N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ? Perhaps it
'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation. I often
inflate hydrogen balloons for my chemistry class. Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to try
the house natural gas (which the bunsen burners usually run on). I
simply could not get the latex balloons to inflate, and I smelled
gas. Clearly, they were much more permeable to methane etc.. It
wasn't CO2, but it at least seems reasonable to me that chemically
selective permeability of the balloon might be an issue. In other
words, the size and/or molar mass of the gas may not be the only factor
(s) affecting its rate of diffusion out of the balloon. Perhaps Mylar
might be worth a try as a comparison?

- Craig
Ernieman
2009-02-09 03:04:26 UTC
Permalink
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2. Example
.. you inflate your car tyres with air. Tyre manufacturers recomend
nitrogen. After a while of filling them with air, you pretty much have 100 %
N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ? Perhaps it
'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation. I often
inflate hydrogen balloons for my chemistry class. Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to try
the house natural gas (which the bunsen burners usually run on). I
simply could not get the latex balloons to inflate, and I smelled
gas. Clearly, they were much more permeable to methane etc.. It
wasn't CO2, but it at least seems reasonable to me that chemically
selective permeability of the balloon might be an issue. In other
words, the size and/or molar mass of the gas may not be the only factor
(s) affecting its rate of diffusion out of the balloon. Perhaps Mylar
might be worth a try as a comparison?

- Craig


Permeability of gases through plastics films is a complex topic. One of the
"rules of thumb" is that increased solubility of the gas in a plastic is
likely to mean inceased permeation rate. Since "like dissolves like", the
solubility is likely to increase from He to CO2, to methane.

Ernie
Ron Jones
2009-02-09 19:37:46 UTC
Permalink
Post by Craig
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2.
Example .. you inflate your car tyres with air. Tyre manufacturers
recomend nitrogen. After a while of filling them with air, you
pretty much have 100 % N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ? Perhaps
it 'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation. I often
inflate hydrogen balloons for my chemistry class. Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to try
the house natural gas (which the bunsen burners usually run on). I
simply could not get the latex balloons to inflate, and I smelled
gas. Clearly, they were much more permeable to methane etc.. It
wasn't CO2, but it at least seems reasonable to me that chemically
selective permeability of the balloon might be an issue. In other
words, the size and/or molar mass of the gas may not be the only
factor (s) affecting its rate of diffusion out of the balloon.
Perhaps Mylar might be worth a try as a comparison?
How did you try to fill the balloons with natural gas? At the tap or with a
pump - tap won't work, natural gas pressure is too low to inflate any
balloon - about 7" water (IIRC) = about 0.25psi.
--
Ron Jones
Process Safety & Development Specialist
Don't repeat history, unreported chemical lab/plant near misses at
http://www.crhf.org.uk Only two things are certain: The universe and
human stupidity; and I'm not certain about the universe. ~ Albert
Einstein
Craig
2009-02-10 01:37:31 UTC
Permalink
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2.
Example .. you inflate your car tyres with air. Tyre manufacturers
recomend nitrogen. After a while of filling them with air, you
pretty much have 100 % N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ? Perhaps
it 'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation.  I often
inflate hydrogen balloons for my chemistry class.  Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to try
the house natural gas (which the bunsen burners usually run on).  I
simply could not get the latex balloons to inflate, and I smelled
gas.  Clearly, they were much more permeable to methane etc..  It
wasn't CO2, but it at least seems reasonable to me that chemically
selective permeability of the balloon might be an issue.  In other
words, the size and/or molar mass of the gas may not be the only
factor (s) affecting its rate of diffusion out of the balloon.
Perhaps Mylar might be worth a try as a comparison?
How did you try to fill the balloons with natural gas?  At the tap or with a
pump - tap won't work, natural gas pressure is too low to inflate any
balloon - about 7" water (IIRC) = about 0.25psi.
It was exactly as simple as you suspect. I just walked up to the tap
and held the balloon around it, expecting that to do the job.

You're right - house natural gas pressure doesn't inflate a balloon
very well. It seems my starry-eyed idea was doomed for more than one
reason.

I just tried it again to refresh my memory. Indeed, the balloon
inflates a pathetic amount, consistent with the pressure being fairly
low. I hold the balloon tightly to the open tap, inflate it as best I
can, and twist the base to make it reasonably "airtight". I then
close the tap and squeeze the barely-inflated balloon. It deflates
and I smell gas. This off-the-shelf (latex?) balloon is clearly
permeable to natural gas.

- Craig
Mark Thorson
2009-02-10 20:56:46 UTC
Permalink
Post by Craig
I just tried it again to refresh my memory. Indeed, the balloon
inflates a pathetic amount, consistent with the pressure being fairly
low. I hold the balloon tightly to the open tap, inflate it as best I
can, and twist the base to make it reasonably "airtight". I then
close the tap and squeeze the barely-inflated balloon. It deflates
and I smell gas. This off-the-shelf (latex?) balloon is clearly
permeable to natural gas.
You didn't smell natural gas. You smelled an odorant
added to the gas (butyl mercaptan).
Dirk Bruere at NeoPax
2009-02-10 22:54:19 UTC
Permalink
Post by Mark Thorson
Post by Craig
I just tried it again to refresh my memory. Indeed, the balloon
inflates a pathetic amount, consistent with the pressure being fairly
low. I hold the balloon tightly to the open tap, inflate it as best I
can, and twist the base to make it reasonably "airtight". I then
close the tap and squeeze the barely-inflated balloon. It deflates
and I smell gas. This off-the-shelf (latex?) balloon is clearly
permeable to natural gas.
You didn't smell natural gas. You smelled an odorant
added to the gas (butyl mercaptan).
Every so often they take a dead skunk, liquidise it and throw it in the
methane tanks at HQ
--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
Ron Jones
2009-02-10 22:46:21 UTC
Permalink
Post by Craig
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2.
Example .. you inflate your car tyres with air. Tyre manufacturers
recomend nitrogen. After a while of filling them with air, you
pretty much have 100 % N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ?
Perhaps it 'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation. I often
inflate hydrogen balloons for my chemistry class. Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to
try the house natural gas (which the bunsen burners usually run
on). I simply could not get the latex balloons to inflate, and I
smelled gas. Clearly, they were much more permeable to methane
etc.. It wasn't CO2, but it at least seems reasonable to me that
chemically selective permeability of the balloon might be an issue.
In other words, the size and/or molar mass of the gas may not be
the only factor (s) affecting its rate of diffusion out of the
balloon. Perhaps Mylar might be worth a try as a comparison?
How did you try to fill the balloons with natural gas? At the tap or
with a pump - tap won't work, natural gas pressure is too low to
inflate any balloon - about 7" water (IIRC) = about 0.25psi.
It was exactly as simple as you suspect. I just walked up to the tap
and held the balloon around it, expecting that to do the job.
You're right - house natural gas pressure doesn't inflate a balloon
very well. It seems my starry-eyed idea was doomed for more than one
reason.
I just tried it again to refresh my memory. Indeed, the balloon
inflates a pathetic amount, consistent with the pressure being fairly
low. I hold the balloon tightly to the open tap, inflate it as best I
can, and twist the base to make it reasonably "airtight". I then
close the tap and squeeze the barely-inflated balloon. It deflates
and I smell gas. This off-the-shelf (latex?) balloon is clearly
permeable to natural gas.
Methane does not smell. It's permeable to ethanethiol. ;-)
--
Ron Jones
Process Safety & Development Specialist
Don't repeat history, unreported chemical lab/plant near misses at
http://www.crhf.org.uk Only two things are certain: The universe and
human stupidity; and I'm not certain about the universe. ~ Albert
Einstein
Craig
2009-02-11 05:19:43 UTC
Permalink
Post by Bruce Sinclair
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
Most rubbers (and many plastics IIRC ?) are more permeable to CO2.
Example .. you inflate your car tyres with air. Tyre manufacturers
recomend nitrogen. After a while of filling them with air, you
pretty much have 100 % N. :)
Why ? The CO2 and O (slower I think ?) escapes faster. Why ?
Perhaps it 'dissolves' in the rubber then permeates ?
I'm sure someone can confirm/deny :)
I can't confirm, but I can offer a related observation. I often
inflate hydrogen balloons for my chemistry class. Regular latex
balloons hold hydrogen gas just fine, at least for an hour or two.
One day, I was looking for another gas and got the bright idea to
try the house natural gas (which the bunsen burners usually run
on). I simply could not get the latex balloons to inflate, and I
smelled gas. Clearly, they were much more permeable to methane
etc.. It wasn't CO2, but it at least seems reasonable to me that
chemically selective permeability of the balloon might be an issue.
In other words, the size and/or molar mass of the gas may not be
the only factor (s) affecting its rate of diffusion out of the
balloon. Perhaps Mylar might be worth a try as a comparison?
How did you try to fill the balloons with natural gas? At the tap or
with a pump - tap won't work, natural gas pressure is too low to
inflate any balloon - about 7" water (IIRC) = about 0.25psi.
It was exactly as simple as you suspect.  I just walked up to the tap
and held the balloon around it, expecting that to do the job.
You're right - house natural gas pressure doesn't inflate a balloon
very well.  It seems my starry-eyed idea was doomed for more than one
reason.
I just tried it again to refresh my memory.  Indeed, the balloon
inflates a pathetic amount, consistent with the pressure being fairly
low.  I hold the balloon tightly to the open tap, inflate it as best I
can, and twist the base to make it reasonably "airtight".  I then
close the tap and squeeze the barely-inflated balloon.  It deflates
and I smell gas.  This off-the-shelf (latex?) balloon is clearly
permeable to natural gas.
Methane does not smell.  It's permeable to ethanethiol. ;-)
The precision of my speech stands duly corrected. :)

I've never been involved in the formulation of natural gas for lab
use, but I would tend to suppose that the odorant is probably only a
tiny fraction of the mixture. If the balloon were permeable only to
the odorant, then squeezing the balloon would result in the expulsion
of the odor but not the rest. Since most of the balloon deflated, I
feel forced to conclude that either:
(i) the balloon is also permeable to methane
(ii) the odorant makes up a very large percentage of the gas mix
I feel that (i) is more likely to be correct, but with this crowd, I
am suddenly feeling the need to write as precisely as
possible... :)

- Craig
sydscience
2009-02-08 23:22:53 UTC
Permalink
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide.  Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation.  How many balloon of each gas?
David A. Smith
Five balloons of each gas. We used two different sources of CO2 on
two separate occasions - one from a compressed CO2 bottle; another by
reaction between sodium bicarbonate and acetic acid - just to
eliminate the possibility of contamination. Results are the same in
each case.
Frank
2009-02-08 23:33:28 UTC
Permalink
Post by N:dlzc D:aol T:com (dlzc)
Post by sydscience
Post by sydscience
My daughter did her science experiment measuring the
deflation rates of latex balloons filled with helium, carbon
dioxide and compressed air. The carbon dioxide balloons
deflated fastest but we have no idea why.
http://www.answerbag.com/q_view/734234
Post by sydscience
Post by sydscience
Does anyone know the reason that carbon dioxide filled
balloons deflate faster than helium or compressed air?
Many thanks.
No reason for this to happen that I know of. How did
you decide rates of deflaton?
We measured the circumference of the balloons
every 30 minutes.
My guess is there is something funny in how you got your carbon
dioxide. Maybe it was hotter than the other gasses, and cooling
added to an *apparent* deflation. How many balloon of each gas?
David A. Smith
It is interesting and I would have guessed that with diffusion and
osmotic pressure the carbon dioxide balloons would have deflated slower.
DuPont had used this phenomenon in a carpet underlay product where
polyester foam was inflated with a high molecular weight gas.

Maybe some interaction of carbon dioxide or oil it may contain to
plasticize or open up the latex.
Bill Penrose
2009-02-09 23:27:11 UTC
Permalink
Post by sydscience
My daughter did her science experiment measuring the deflation rates
of latex balloons filled with helium, carbon dioxide and compressed
air.  The carbon dioxide balloons deflated fastest but we have no idea
why.  Does anyone know the reason that carbon dioxide filled balloons
deflate faster than helium or compressed air?
That's surprising, but depending on the balloon material, the
permeability of gases is due more to their 'solubility' in the
membrane material, not the size of the gas molecules. Helium is not
very soluble in organic materials, and may actually escape through
pores, but CO2 would have to dissolve in the membrane and diffuse away
on the other side.

Why not try 'canned air'? That's actually a polyfluoro-something-or-
other with a very high molecular weight. It's also soluble in organic
substances. See how that works. (Note: this is a hypothesis that can
be tested a la the scientific method.) The hardware store and computer
stores stock it.

It's also kind of funny to see balloons that fall like cinder blocks.

Dangerous Bill
dlzc
2009-02-10 16:36:05 UTC
Permalink
Post by Bill Penrose
Post by sydscience
My daughter did her science experiment measuring
the deflation rates of latex balloons filled with helium,
carbon dioxide and compressed air.  The carbon
dioxide balloons deflated fastest but we have no idea
why.  Does anyone know the reason that carbon
dioxide filled balloons deflate faster than helium or
compressed air?
That's surprising, but depending on the balloon
material, the permeability of gases is due more to
their 'solubility' in the membrane material, not the
size of the gas molecules. Helium is not very soluble
in organic materials, and may actually escape
through pores, but CO2 would have to dissolve in the
membrane and diffuse away on the other side.
I wonder if the latex membrane depends in part on adsorbed water to
fill the pores? How does cured latex behave in ultra-dry conditions?

David A. Smith
Bill Penrose
2009-02-11 18:44:30 UTC
Permalink
Post by dlzc
I wonder if the latex membrane depends in part on adsorbed water to
fill the pores?  How does cured latex behave in ultra-dry conditions?
No idea. We did experiments on selective permeation about 10 years ago
and the appropriate background reading to accompany it. The conclusion
was that it's a bad idea to use straight permeation. It's too
unpredictable and subject to too many factors.

Certainly silicone, which can absorb up to 13% water, changes its
properties, but we never looked at latex.

DB
Mark Thorson
2009-02-11 19:24:07 UTC
Permalink
Post by Bill Penrose
Certainly silicone, which can absorb up to 13% water, changes its
properties, but we never looked at latex.
What kind of silicone is that? PDMS silicone is
very hydrophobic.
Bill Penrose
2009-02-11 23:22:24 UTC
Permalink
Post by Bill Penrose
Certainly silicone, which can absorb up to 13% water, changes its
properties, but we never looked at latex.
What kind of silicone is that?  PDMS silicone is
very hydrophobic.
So it seems, to liquid water anyway. Water vapor goes through PDMS
like it wasn't there. I used to measure gas supersaturation in water
with a coil of PDMS tubing. From the pressure that developed in the
tube, the partial pressure of O2 + N2 relative to atmospheric was
derived by subtracting the water vapor partial pressure at that
temperature. Our method was similar to this:
www.chelanpud.org/HCP/Studies/2001%20Report.pdf (page 10)

We could use PDMS for humidification of gases, except that Nafion
tubing works better.

PDMS is sometimes added to other polymers to improve vapor
permeability.
www.siliconespectator.com/articles/September_2008.pdf

DB
N:dlzc D:aol T:com (dlzc)
2009-02-11 23:50:25 UTC
Permalink
Dear Bill Penrose:

"Bill Penrose" <***@gmail.com> wrote in message news:643afdaf-51d2-4436-a65b-***@n5g2000prc.googlegroups.com...
...
Post by Bill Penrose
So it seems, to liquid water anyway. Water vapor
goes through PDMS like it wasn't there. I used to
measure gas supersaturation in water with a coil
of PDMS tubing.
I've had similar experience with copper tubing. Dry an air
stream to -100degfF dewpoint, and shut it off for a few days. By
the time you start air flow again, the humidity will have climbed
quite a bit.

David A. Smith
Mark Thorson
2009-02-12 03:53:14 UTC
Permalink
Post by Bill Penrose
Post by Mark Thorson
Post by Bill Penrose
Certainly silicone, which can absorb up to 13% water, changes its
properties, but we never looked at latex.
What kind of silicone is that? PDMS silicone is
very hydrophobic.
So it seems, to liquid water anyway. Water vapor goes through PDMS
like it wasn't there. I used to measure gas supersaturation in water
That's permeability, not water absorption. PDMS silicone
has one of lowest water absorptions of any polymer.
Certainly not anywhere close to 13%, not for unmodified
PDMS or methyl-phenyl silicones.

It is, however, among the most permeable polymers to
water, gases, solvents, etc. It will have a high
absorption of hydrophobic solvents, but almost no
absorption of water.
Bill Penrose
2009-02-12 16:32:54 UTC
Permalink
...That's permeability, not water absorption.  PDMS silicone
has one of lowest water absorptions of any polymer.
I defer. I couldn't find any info to back up my statement, so I have
to assume it's a misfiled memory thing.

DB
Ron Jones
2009-02-10 22:47:45 UTC
Permalink
Post by Bill Penrose
Post by sydscience
My daughter did her science experiment measuring the deflation rates
of latex balloons filled with helium, carbon dioxide and compressed
air. The carbon dioxide balloons deflated fastest but we have no idea
why. Does anyone know the reason that carbon dioxide filled balloons
deflate faster than helium or compressed air?
That's surprising, but depending on the balloon material, the
permeability of gases is due more to their 'solubility' in the
membrane material, not the size of the gas molecules. Helium is not
very soluble in organic materials, and may actually escape through
pores, but CO2 would have to dissolve in the membrane and diffuse away
on the other side.
Why not try 'canned air'? That's actually a polyfluoro-something-or-
other with a very high molecular weight. It's also soluble in organic
substances. See how that works. (Note: this is a hypothesis that can
be tested a la the scientific method.) The hardware store and computer
stores stock it.
It's also kind of funny to see balloons that fall like cinder blocks.
Dangerous Bill
You want Xenon to do that. Might be a tad expensive...
--
Ron Jones
Process Safety & Development Specialist
Don't repeat history, unreported chemical lab/plant near misses at
http://www.crhf.org.uk Only two things are certain: The universe and
human stupidity; and I'm not certain about the universe. ~ Albert
Einstein
Dirk Bruere at NeoPax
2009-02-10 22:55:24 UTC
Permalink
Post by Ron Jones
Post by Bill Penrose
Post by sydscience
My daughter did her science experiment measuring the deflation rates
of latex balloons filled with helium, carbon dioxide and compressed
air. The carbon dioxide balloons deflated fastest but we have no idea
why. Does anyone know the reason that carbon dioxide filled balloons
deflate faster than helium or compressed air?
That's surprising, but depending on the balloon material, the
permeability of gases is due more to their 'solubility' in the
membrane material, not the size of the gas molecules. Helium is not
very soluble in organic materials, and may actually escape through
pores, but CO2 would have to dissolve in the membrane and diffuse away
on the other side.
Why not try 'canned air'? That's actually a polyfluoro-something-or-
other with a very high molecular weight. It's also soluble in organic
substances. See how that works. (Note: this is a hypothesis that can
be tested a la the scientific method.) The hardware store and computer
stores stock it.
It's also kind of funny to see balloons that fall like cinder blocks.
Dangerous Bill
You want Xenon to do that. Might be a tad expensive...
I did it with Xenon once. Very impressive and very expensive.
I had considered breathing it to see if my voice changed, but didn't
have enough.
--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
Mark Thorson
2009-02-11 00:05:00 UTC
Permalink
Post by Dirk Bruere at NeoPax
I did it with Xenon once. Very impressive and very expensive.
I had considered breathing it to see if my voice changed, but didn't
have enough.
I wonder if that would have been dangerous.

How quickly could xenon be cleared from the
lungs?
Dirk Bruere at NeoPax
2009-02-11 00:54:59 UTC
Permalink
Post by Mark Thorson
Post by Dirk Bruere at NeoPax
I did it with Xenon once. Very impressive and very expensive.
I had considered breathing it to see if my voice changed, but didn't
have enough.
I wonder if that would have been dangerous.
How quickly could xenon be cleared from the
lungs?
I though about that, and decided that if I fainted from lack of O2 I
needed someone to hold me upside down while doing a bit of CPR.
--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
Craig
2009-02-11 06:04:08 UTC
Permalink
Post by Dirk Bruere at NeoPax
Post by Mark Thorson
Post by Dirk Bruere at NeoPax
I did it with Xenon once. Very impressive and very expensive.
I had considered breathing it to see if my voice changed, but didn't
have enough.
I wonder if that would have been dangerous.
How quickly could xenon be cleared from the
lungs?
I though about that, and decided that if I fainted from lack of O2 I
needed someone to hold me upside down while doing a bit of CPR.
I had exactly the same concerns. Then I saw videos of people actually
doing it, although using sulfur hexafluoride.

Adam Savage from the Mythbusters tried it:



However, that clip doesn't show what happens afterwards. The
continued presence of Adam on the show suggests that he lived
somehow. :)

The clip below shows someone inhaling SF6 and then simply breathing a
few times to clear the lungs. (This isn't posted by the copyright
holder, but it was the best I found demonstrating what happens after
inhaling SF6.)



I think the guy on the left in the clip above is Steve Spangler.
Spangler definitely demonstrated this on the Ellen show:



Again, you can see that Ellen exhales a few times and clears the stuff
out of her lungs.

I'm convinced that, if you're careful, you can do this without the
need to hang upside down. I haven't yet gotten around to trying this
myself.

- Craig
Dirk Bruere at NeoPax
2009-02-22 03:01:27 UTC
Permalink
Post by Craig
Post by Dirk Bruere at NeoPax
Post by Mark Thorson
Post by Dirk Bruere at NeoPax
I did it with Xenon once. Very impressive and very expensive.
I had considered breathing it to see if my voice changed, but didn't
have enough.
I wonder if that would have been dangerous.
How quickly could xenon be cleared from the
lungs?
I though about that, and decided that if I fainted from lack of O2 I
needed someone to hold me upside down while doing a bit of CPR.
I had exactly the same concerns. Then I saw videos of people actually
doing it, although using sulfur hexafluoride.
http://youtu.be/d-XbjFn3aqE
However, that clip doesn't show what happens afterwards. The
continued presence of Adam on the show suggests that he lived
somehow. :)
The clip below shows someone inhaling SF6 and then simply breathing a
few times to clear the lungs. (This isn't posted by the copyright
holder, but it was the best I found demonstrating what happens after
inhaling SF6.)
http://youtu.be/HIXEzj08MwE
I think the guy on the left in the clip above is Steve Spangler.
http://youtu.be/2qlb8X_ffO8
Again, you can see that Ellen exhales a few times and clears the stuff
out of her lungs.
I'm convinced that, if you're careful, you can do this without the
need to hang upside down. I haven't yet gotten around to trying this
myself.
I wonder what fluorine impurities one might encounter in a "bad" batch
of SF7?
--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff
Michael Moroney
2009-02-13 14:07:37 UTC
Permalink
Post by Ron Jones
Post by Bill Penrose
It's also kind of funny to see balloons that fall like cinder blocks.
You want Xenon to do that. Might be a tad expensive...
Sulfur hexafluoride. Cheaper and a higher MW than Xenon.
Bruce Sinclair
2009-02-16 00:05:35 UTC
Permalink
Post by Michael Moroney
Post by Ron Jones
Post by Bill Penrose
It's also kind of funny to see balloons that fall like cinder blocks.
You want Xenon to do that. Might be a tad expensive...
Sulfur hexafluoride. Cheaper and a higher MW than Xenon.
.. *but* a known green house gas :) :)
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