Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Science

Mixing the Unmixable 254

Posted by michael from the shaken-not-stirred dept.
markthebrewer writes "From an article in the New Scientist: Conventional wisdom every 15 year-old knows says that you can't mix oil and water without some kind of surfactant. However a team lead by Richard Pashley from the Australian National University in Canberra have done it simply by first removing all dissolved gases from the water. Apart from the obvious potential improvements in salad dressings, it could have an impact on the manufacture of everything from drugs to paint - anywhere an emulsion is required. Apparently, it will also give some insight into the mysterious 'long-range hydrophobic effect' (or why oil droplets coalesce over surprisingly long distances)." Keep in mind the usual scientific caveat: this experiment doesn't seem to have been replicated by other experimenters yet.
This discussion has been archived. No new comments can be posted.

Mixing the Unmixable More

Mixing the Unmixable

Comments Filter:

  • not real science (Score:2, Insightful)

    by Anonymous Coward
    Keep in mind the usual scientific caveat: this experiment doesn't seem to have been replicated by other experimenters yet.
    AKA: "Uh, guys, some soap fell into the bottle but let's pretend there isn't any and call it science!"

  • Excuse me... (Score:5, Funny)

    by Some Woman ( 250267 ) on Thursday February 20, 2003 @05:12PM (#5347566) Journal
    But where are these 15-year olds who know what a surfactant is? :)
    • This is slashdot! It's _cool_ to be arrogant!

    • Re:Excuse me... (Score:2, Insightful)

      by willll ( 635932 )
      well now that i read the link i no what a surfactant is. and i'm 15. so, here i am.

      • Re:Excuse me... (Score:5, Funny)

        by Anonymous Coward on Thursday February 20, 2003 @05:30PM (#5347705)
        "i read the link i no what a surfactant is"

        i "no"?

        Geeze
    • "But where are these 15-year olds who know what a surfactant is? :)"

      I know exactly what that is. It's an espresso maker.

      (somehow, Arnold Schwarzenegger quotes just don't have the same bite to them that Homer Simpson or Arnold Rimmer have.)
    • When I was about 13 or so (7th or 8th grade I can't remember), I did an science fair experiment with mixing oil and water and found I had to add soap to get them to mix. It was pretty cool.

      So here I am!! I was a 15 year old (actually younger) that knew about surfactants! Now I'm 24 though, but I still remember the geekyness of my youth :).

    • Re:Excuse me... (Score:5, Informative)

      by antis0c ( 133550 ) on Thursday February 20, 2003 @05:30PM (#5347707)
      Other people might know it as an emulsifier.

    • Re:Excuse me... (Score:5, Funny)

      by Elwood P Dowd ( 16933 ) <judgmentalist@gmail.com> on Thursday February 20, 2003 @05:42PM (#5347799) Journal
      But where are these 15-year olds who know what a surfactant is? :)

      Every single one. What did you do to wash the vasoline off your hands?
    • Isn't that, like, a dude who just pretends to know how to surf, but really can't, so he just acts like it?

    • Wrong word (Score:3, Interesting)

      by Bruce Perens ( 3872 )
      And it's not unmixable, it's immiscible.

      Bruce

      • Re:Wrong word (Score:2, Interesting)

        by cyrek ( 556620 )
        If you're going to be picky, the words mixable and miscible are both derived from the Latin miscere. The different spellings have yet to to diverge in meaning, so they mean the same thing.

        <dig> The only reason 'mixable' isn't in the accepted jargon-set is that it isn't confusing to non-scientists. ;-) </dig>

  • I wonder (Score:3, Interesting)

    by antiprime ( 121253 ) on Thursday February 20, 2003 @05:12PM (#5347569) Journal
    What the environmental impact of water based oils will be.

    • Re:I wonder (Score:2, Interesting)

      by Dr.Enormous ( 651727 )
      Well, off the top of my head, you'll probably have two competing effects (assuming this is real and the stuff stays emulsified when you pour it down the drain):
      1. Dissolved oils/other hydrophobic molecules will reach more areas. Which is bad.
      2. Dissolved oils will get diluted in the environment more, possibly to non-toxic levels. Which is good.

      Now, which of those would outweigh the other, who knows?

    • Re:I wonder (Score:3, Funny)

      by ackthpt ( 218170 )
      What the environmental impact of water based oils will be.

      Hmm, maybe any of the following:

      Exxon-Valdez bottled water

      No mo' GoJo

      Vegetable oils that penetrate the skin and enter the blood stream (Lube your Heart with new STP Salad Dressing!)

      McD's marinates fries in tallow juice. (Ecch)

      Uncannily something related to CowboyNeal

  • Now I need ... (Score:5, Funny)

    by burgburgburg ( 574866 ) <splisken06@TOKYOemail.com minus city> on Thursday February 20, 2003 @05:13PM (#5347570)
    to adjust my phrasing:

    It's like mixing oil and water, assuming that all of the dissolved gases haven't been removed from the water.

    Yeah, that rolls off the tongue.

  • If they argue over the results, or the credit... (Score:3, Funny)

    by jo_ham ( 604554 ) <joham999@ g m a il.com> on Thursday February 20, 2003 @05:13PM (#5347574)
    ..they'll have trouble pouring oil on troubled waters, it'll just mix in.

  • Not replicated by other scientists? (Score:5, Funny)

    by macshune ( 628296 ) on Thursday February 20, 2003 @05:13PM (#5347575) Journal
    Can we say Pons and Fleischmann salad dressings?

  • how funny (Score:2, Funny)

    by choctawgh ( 652121 )
    Am I the only one that finds it funny that the first, most obvious benefit mentioned in the caption was food related? Salad dressing indeed ;)

  • But how will I describe my bad relationships? (Score:4, Funny)

    by robb0995 ( 633070 ) on Thursday February 20, 2003 @05:16PM (#5347611)
    "Yeah, we were like oil and water without a sulfacant!"

  • A better headline: (Score:3, Funny)

    by Randolpho ( 628485 ) on Thursday February 20, 2003 @05:16PM (#5347614) Homepage Journal
    Scientists mix oil and water.

    In other news, record sub-zero temperatures in hell.
    • It has gotten so cold that a thick blanket of snow now covers Hell. In response, the Devil Himself was quoted as saying, "If only science allowed water to be homogenously mixed with oil indefinately, I'd be able to fire up the furnace again and deep fry the shit out of who ever did this"

  • hydrophobic (Score:3, Funny)

    by sczimme ( 603413 ) on Thursday February 20, 2003 @05:17PM (#5347617)

    "He takes the air out and he doesn't get the long-range hydrophobic force. It doesn't nail the hydrophobic force down, but now we have something to work on," says James Quirk, a chemist at the University of Western Australia in Perth..."

    Hydrophobic, eh? So that's the reason they don't mix: the oil is afraid of the water. Neat.

    PS I wonder if the chemist's middle initial is T.

  • From the article... (Score:3, Funny)

    by Drunken_Jackass ( 325938 ) on Thursday February 20, 2003 @05:20PM (#5347642) Homepage
    Apparently they were able to pass both the oil and water through an new Irish web browser. The 4-fold increase in speed of all of the particles is what allowed the mixing.

  • Of course!!!!! (Score:5, Funny)

    by Picass0 ( 147474 ) on Thursday February 20, 2003 @05:22PM (#5347651) Homepage Journal
    >> "...simply by first removing all dissolved gases from the water."

    Ahhh, Once you remove all of the Hydrogen and Oxygen I can see where there would no longer be a problem!!!

  • Good Eats (Score:5, Funny)

    by esobofh ( 138133 ) <`ten.sulet' `ta' `ghk'> on Thursday February 20, 2003 @05:23PM (#5347662)
    Great, hopefully Alton Brown can make a super mayonnaise emulsion based on this theory - super tasty and smooth on the tongue, now that's Good Eats!

  • I call BS (Score:3, Insightful)

    by Namds ( 631686 ) on Thursday February 20, 2003 @05:27PM (#5347686)
    This has got to be a dupe. Think of all of the biological effects that would be couteracted by this. Hydrophobic/hydrophilic effects are the basic reason why proteins fold the way that they do, and biological system's don't have free gasses floating around. Not to mention what would happen to all of our membranes (note, membrane formation is also due to hydophobic/hydophilic effects). Gasses in a biological system are all bound to something - example - Oxygen is bound to hemoglobin or myoglobin, if it isn't it causes serious problems. If water and oil mix without gasses present then we're in a world of hurt and I'd just be mush right now instead of typing this.
    • A dupe? Kinda mixed up eh?

      What evidence do you have that gases are not dissolved in our body fluids?

      Mod this puppy to the basement.

      • You are correct (Score:2, Informative)

        by mrfunnypants ( 107364 )
        What evidence do you have that gases are not dissolved in our body fluids?

        Correct to the contrary it is well known that dissovled gases are in our blood stream. This is partly how CO2 travels, indeed a small percentage but still occurs.

    • Re:I call BS (Score:4, Informative)

      by FroBugg ( 24957 ) on Thursday February 20, 2003 @05:35PM (#5347743) Homepage
      There's a difference between gases in the air and dissolved gases. All the water that you deal with normally has dissolved gases. Dissolved oxygen in both fresh and sewater is how fish and other gilled creatures live. Dissolved nitrogen in our blood is responsible for decompression sickness among divers.

    • Re:I call BS (Score:5, Interesting)

      by kavau ( 554682 ) on Thursday February 20, 2003 @05:48PM (#5347842) Homepage
      The focus here shouldn't be on the word gasses, but rather on impurities contained in the water. My impression is that they created the analogue of a supercooled gas: if you cool a gas very slowly and carefully below its condensation temperature, and there are no catalysts present, it may remain in a metastable gaseous phase. But as soon as it is disturbed (by the presence of impurities, for example) it will condense into a liquid state, which is the stable thermodynamic state at that temperature.

      The oil-water mixture is probably also a metastable state. In the presence of any catalysts (in this case dissolved gases; in the case of biological systems this function could be taken over by proteins, salt ions, I-don't-know-what-else...) the oil molecules would condense and clot together. Oil droplets are thermodynamically stable only above a certain droplet size; the same is true for water droplets in the case of the supercooled gas. Without catalysts, the critical droplet size cannot be achieved.

    • "This has got to be a dupe."

      I have only seen this article posted once, maybe tomorrow it will be a dupe.
    • What are you talking about?

      I call BS on your silly assertion that "biological system's don't have free gasses floating around."

      On the contrary, your cells are full of oxygen dissolved in water. Or don't you breathe? You also have carbon dioxide, nitrogen, and all sorts of other gases from air dissolved in your body.

      (The dissolved nitrogen is what causes the bends when divers come up too fast.)

    • Re:I call BS (Score:2, Informative)

      by paxil ( 99137 )

      Gasses in a biological system are all bound to something - example - Oxygen is bound to hemoglobin or myoglobin, if it isn't it causes serious problems.

      No.

      How do you suppose the O2 makes it way to the hemoglobin?

      Well, I'll tell you:
      the oxygen diffuses through the cell membranes of the alveoli, disolves in the liquid component of the blood, diffuses through the cell membrane of the Red Blood Cells, and binds to the hemoglobin.

      Of course, the oxygen bound to hemoglobin is in equilibrium with the oxygen disolved in the RBC's cytoplasim, which is in equilibrium with the oxygen disolved in the liquid component of blood. (I am simplifying, but you get the idea.)

      It may be biology, but it isn't black magic how this stuff works, the laws of physical chemistry must still be obeyed, there has to be an equilibrium between the phases.

      This aspect of blood is pretty well understood too:
      there is 0.03ml oxygen per liter of blood per mm Hg partial pressure of oxygen, or about 2.9ml oxygen disolved per litre of arterial blood, and 1.2ml of disolved oxygen per litre of venous blood. Breathing 100 percent oxygen will, of course, increase these numbers.

    • Boiled water. Ever put olive oil on top of water you're going to put spaghetti in? It degasses pretty thoroughly before it hits a rolling boil, but the oil remains on top and doesn't emulsify even when it hits a boil.

  • techno? (Score:3, Funny)

    by misterhaan ( 613272 ) on Thursday February 20, 2003 @05:28PM (#5347697) Homepage Journal
    yeah after reading just the headline i thought this was about music . . .

  • WTF is going on here? (Score:5, Interesting)

    by cryptochrome ( 303529 ) on Thursday February 20, 2003 @05:29PM (#5347701) Journal
    From the article...

    An alternative might be to disperse the medicine in degassed water, which is already produced on a large scale by the oil industry.

    You're telling me the oil industry itself makes degassed water on a large scale - for some unmentioned reason - and didn't discover this researcher's claims that oil and degassed water spontaneously emulsify? What's up with that?

    • Re:WTF is going on here? (Score:4, Funny)

      by ifreakshow ( 613584 ) on Thursday February 20, 2003 @05:46PM (#5347827)
      They discovered it 20 years ago but immediately covered up the knowledge because it could be used to make cars that get 200 miles to the gallon and don't produce greenhouse gasses.
      • I know this is a joke, but I did see something on television about someoen who claimed to have mixed water with petrol and made his car 20 times more efficient. Then the story seemed to die, with no debunking that I recall. Probably unrelated, but an interesting thought...

        • Re:WTF is going on here? (Score:5, Informative)

          by lommer ( 566164 ) on Thursday February 20, 2003 @08:28PM (#5348981)
          "someoen ... mixed water with petrol and made his car 20 times more efficient."

          This has been done by drag racers for years, and as another poster mentioned, was even used in spitfires in WWII. The reason it works is the same principal as a steam engine: hot water -> steam, expanding dramatically in the process, thus providing more pressure on the piston. However, the high temperatures in an engine cause some of the water to be ripped apart into H2 and O2, at which point the H2 can recombine to form highly acidic compounds that corrode your engine and reduce its operating life many times over. That is why it is not commonly used unless super-high torque is required from an engine NOW and you don't care how long the engine lasts after that.

          Of course, there's still the other obvious problem of putting too much water in your gas...
          • Big engines like what you are talking about inject water into the air intake, they don't mix it with gas. The water has a cooling effect which increases intake air density and power much like an intercooler on a turbocharged engine. Also, water helps prevent pinging (premature detonation) which allows higher compression ratios to be used, further increasing power output. So, the engines aren't doing anything especially interesting since they are only mixing gas vapor and water vapor.
            • I was about to say. Evaporating water can only take energy from the system, reducing the temperature and pressure of the explosion. Maybe the pressure is reduced less by the vapor pressure of the steam, but I don't see it improving the compression.

              Slowing the reaction to make the compression follow a more efficient curve makes sense.
    • Oil industry == petrol industry, which does not use fat oils, to my knowledge. My guess is that the oil industry uses degassed water while drilling, since it's probably very chemically inert.

  • Urm.. Soap? (Score:2, Informative)

    by ChuckleBug ( 5201 )
    It's always been possible to mix oil and water with a little thing called SOAP. Or surfactant, to be more precise. Or detergent. You get my drift.

    It was once my job to figure out how to get oil out of wastewater, and it could be a really difficult problem. Oil/water emulsions are nothing new.

  • Be aware that the New Scientist is not a peer reviewed journal.

    The two guys who claimed that they produced cold fusion in a laboratory also didn't publish in a peer reviewed journal. It turns out they were full of crap. Just 'cause it's written doesn't make it so. Once it's in a peer reviewed journal, I'll seriously be interested (chemistry news on /., is that usual?).

    Anyway, the New Scientist is well known for its overhyping of science.

  • What's Next?! (Score:3, Funny)

    by Kenshin ( 43036 ) <`ac.skrowranul' `ta' `nihsnek'> on Thursday February 20, 2003 @05:38PM (#5347767) Homepage
    Cats and dogs living togther?!

  • french dressing (Score:3, Funny)

    by frovingslosh ( 582462 ) on Thursday February 20, 2003 @05:40PM (#5347783)
    French dressing

    The effect prevents oil's dispersion in water, and means that you can only make oil and water emulsions, such as French dressing for salads, by shaking them and adding stabilising agents. ?

    Second of all, the oil/water thing is more of an Italian dressing, I believe; and First of all, we don't call it french dressing any more, we call it Freedom Dressing.

    • Second of all, the oil/water thing is more of an Italian dressing, I believe; and First of all, we don't call it french dressing any more, we call it Freedom Dressing.

      I call it nasty... Tom-ay-toe... Tom-ah-toe...
  • Whew!
    I thought it was about Bill Gates and RMS having a love child together.
  • Every oil change I have ever gotten from Meineke for a car I think has been "mixed with water".

  • Stoopid question ... (Score:3, Interesting)

    by DogIsMyCoprocessor ( 642655 ) <{dogismycoprocessor} {at} {yahoo.com}> on Thursday February 20, 2003 @05:46PM (#5347826) Homepage
    how exactly is "mixing" defined? If I put olive oil and tap water in my blender, and crank it on high, it is pretty well mixed, at least temporarily. Is it critical that the "mixture" stay "mixed" over time?

    • Re:Stoopid question ... (Score:5, Informative)

      by DigitalSorceress ( 156609 ) on Thursday February 20, 2003 @06:12PM (#5348044)
      There are many products where oil-based and water-based things need to be mixed together and where it would be a bad thing if they separated. You have probably seen the phrase "such-and-such used as an emulsifier" (sp?) on the ingredients of some food-products.

      Real-world example of wanting something to stay mixed: Paint

      Have you ever opened a can of paint that's been sitting around in your basememt or garage for a few years? Some of the resinous compounds separate from the base materials the same way that the Olive Oil in your blender will eventually rise to the top again once you turn it off. Paint is more viscous and is not simply oil and water, but the same forces are in play.

      The end result is that there is certainly commercial need for things to stay mixed together over longer times.

  • More reading for the curious (Score:5, Informative)

    by tonyhill ( 590105 ) on Thursday February 20, 2003 @05:55PM (#5347891)
    Here's the link to the actual journal [acs.org] his article was published in, for the curious.

    From the article, it would be a stretch to say that Pashley has found a way to overcome "long-range" hydrophobic effects. Those effects are still present. However, he has found a way to get the hydrophobic liquid to break away in small droplets. Once broken away from the bulk, standard DLVO theory [uchicago.edu] takes over to keep the particles apart. DLVO is not a cancelation of hydrophobic effects, it is just an overpowering of hydrophobic effects by electrostatic effects.

    Unfortunately, it seems as though Pashley has no good explanation for why the degassing method works, it just does. This could be interesting, as more researchers study the role of gasses in keeping hydrophobic and hydrophilic liquids apart.

    Overall, quite interesting, though New Scientist does tend to exagerate scientific findings.
    Tony

  • Energy Companies (Score:3, Funny)

    by ruvreve ( 216004 ) on Thursday February 20, 2003 @06:02PM (#5347944) Journal
    An alternative might be to disperse the medicine in degassed water, which is already produced on a large scale by the oil industry.

    If the oil industry uses this on a large scale it would seem that accidents would have happened where the oil came into contact with this degassed water. Those damn energy companies have known all along.....OIL AND WATER DO MIX!

  • This would be good for soda, such as Code Red, which contains Brominated Vegetable Oil, a chemical on the FDA's watch list as a potentially poisonous compound.

    • Re:Good for Soda (Score:3, Interesting)

      by PCM2 ( 4486 )
      This would be good for soda, such as Code Red, which contains Brominated Vegetable Oil, a chemical on the FDA's watch list as a potentially poisonous compound.
      So you're saying this discovery would let them add more brominated vegetable oil to the soda, thus killing you quicker?

      Geeks note: Brominated vegetable oil is also an ingredient in Mountain Dew, and probably other of your favorite flavors of synthi-caff.

  • As a chemist... (Score:5, Informative)

    by smoondog ( 85133 ) on Thursday February 20, 2003 @06:22PM (#5348138)
    I think the /. article is a little misleading. After scanning the JPhysChem B article here (You may need to have a license) [acs.org]. The articles suggest that removing dissolved gasses allows you to mix oil and water indefinately. I'm pretty sure that this is not true.

    They are adding 2 ml of oil and 33 mils of water and after mixing they still have some oil phase (from the picture in the paper). They are reporting an increase in the solubility, not that oil and water in these conditions are completely miscible as implied by the /. article.

    As for my questions, I'm not sure I understand their results with respect to the observation that re-exposure to air doesn't immediately reverse the effect. This sort of raises a red flag to me, because (assuming there isn't any covalent chemistry going on) it means that achieving equilibrium is rather slow, and it may be that they are not at equilibrium when the measurements are made. Either way it is an interesting paper. (This would be better phrased as a question than a statement, I might have just missed the answer in the paper....)

    -Sean
    • Well, we've got a nice tank of helium here so we can degas the solutions we put into our chromatography setup. I'm tempted to actually try this out with some ddH2O and a little immersion oil.

      Do you think that NIH knows that it funds this kind of late night experiments?

      (I might have to make a few latex glove helium balloons too)

  • Already been done? (Score:2, Informative)

    by kaltkalt ( 620110 )
    check out http://www.activusa.com/ [activusa.com]

  • Deep in the lab ... (Score:4, Funny)

    by YetAnotherName ( 168064 ) on Thursday February 20, 2003 @06:59PM (#5348382) Homepage
    Scientist: I've done it. I've DONE IT! Two parts gin ... one part vermouth ... and an olive. They MIX! Mwuahahaha!

    Grad student: Uh, that's just a martini, and not a very dry one.

    Scientist: Blast! Well, bottom's up. We'll just change gin to "oil" and vermouth to "water" and publish anyway.

  • Hmmm...... (Score:5, Interesting)

    by the eric conspiracy ( 20178 ) on Thursday February 20, 2003 @07:44PM (#5348666)
    You folks are missing the key point in the article:

    "The mix spontaneously formed a cloudy emulsion".

    This is very different from the usual case where you take an oil and water mix and maybe some surfactant and agitate it.

    The reason is that the formation of surface area during the dispersion of oil into water normally requires an energy input. Surfactant reduces the energy required and also often stabilizes an emulsion by adding some repulsive forces (either steric or electrostatic) between the droplets. However, with the exception of systems called microemulsions that increased surface area always represents a energy increase. With time (the amount of time depending on the use of suractant etc.) that free energy will cause the emulsion to break and form two homogeneous layers.

    Microemulsions are the exeception; they are unusually favorable systems that reduce the energy of formation of surface area to near zero, probably less than the thermal energy kT available. Thus they can spontaneously form emulsions that are stable indefinitely. Microemulsions generally require very specific compositions to form so they are not often seen except in some specialized applications.

    The problem with Pashley's work is that he is claiming the spontaneous formation of an emulsion.. This would normally be expected only if the surface energy of his mixture was near zero - and there is nothing in the description of this system to indicate that this is happening, regardless of the side show with air bubbles.

    What is more likely is that his oil-water system actually contains some small amount of surfactant as an impurity (quite typical in many oils). If so, the process of lowering temperature will take this mixture through what is known as the phase inversion temperature, where the mixture will achieve a minimum surface tension. This lowered usrface tension will make formation of an emulsion with minimal energy input quite likely.

  • I could not repeat it (Score:3, Interesting)

    by Morgoth_Bauglir ( 261701 ) on Thursday February 20, 2003 @10:41PM (#5349658)
    methodology: I boiled a cup of water in the microwave. I waited for it to cool, and boiled it again. I let it cool and boiled it again. I carefully removed the cup and let a few drops of (extra virgin olive) oil drip onto the surface from about 1cm height to minimize air bubbles.

    observations: the oil stayed in a tight slick on the surface for about 10 seconds. Then it spread out, I'm assuming because of the heat of the water.

    After a about 45s, a piece of wood was introduced to the water, which caused mild boiling suggesting that the water had indeed been devoid of air.

    After more than 30 mnutes, the slick was still on the surface without mixing.

    Conclusions: those guys are need to accumulate more data.
  • WD39... it mixed with the water instead of repelling it.

  • So, does this mean I will no longer have to use soap and shampoo when I shower? I can simply use specially prepared water with the dissolved gases removed, and all the oily, smelly dirt on my skin and in my hair will dissolve and wash right off.

  • is peanut butter, you know when you have to stir it up because all the oil is sitting on top or else it will be thick and unspreadable. Of course it's funny when you give the dog (or I suppose cat but I can't imagine that being as good) a spoonful of PB and stick it to the roof of their mouth. Totally hilarious while s/he works on it for a good 20mins to 2hours.
  • This is cool because,
    1. it's experimentally falsibiable. The statement, "oil will emulse better in water which has had all dissolved gasses removed" can be put to the test, and possibly disproved, and
    2. you can duplicate this experiment in the kitchen!

    To remove all dissolved gasses from water, simply heat the water at a "Low" setting and bring it slowly to a boil. It's that simple. There's a kids' science experiment to demonstrate this effect at http://www.bigelow.org/virtual/handson/diss_air.ht ml [bigelow.org]. Watch for those air bubbles during heating to verify that the water has dissolved gasses already.

    Put the de-gassed water in a sealed container (a soda bottle) and put some of the original water in an identical (but labeled) container. Collect water from other sources (tap, lake, well), splitting those into original and de-gassed containers in the same way. A sample from a fish tank is guaranteed to have plenty of dissolved gasses, otherwise the fish would be dead. Getting different water sources gives reasonable independence from the effects of non-gaseous impurities (minerals, for example) on your results. Let all water bottles come to the same temperature.

    Choose an oil to try. Then for each bottle of water, prepare another container with a small amount of oil. Add a small amount of each type of water to those oil samples and shake vigorously.

    Quantify what you see by measuring the time that it takes for all (or most) of the re-separation to happen. Remember, what you're looking for is any consistent difference between the original and de-gassed samples.

    You should have plenty of water left, so rinse out those mixing containers and try different oils: canola oil, corn oil, baby oil, motor oil, etc. If you really want to be thorough, put all the water bottles in the refrigerator to try the experiment at another temperature.

    If you try all this and you can't see any difference in the mixing between the original and de-gassed water, then you have disproved the theory. If you do see differences, then you have successfully duplicated the experiment.

    There you go. You're a scientist!

    • Duh!

      Don't shake in bottles. What was I thinking? Put the oil and water into a zip-lock bag with no air and squish it all around to mix.

      Incidentally, my own experiments have so far shown no difference in emulsion effects between normal and de-gassed water ...so far.

      -Rick

Slashdot Top Deals

Every successful person has had failures but repeated failure is no guarantee of eventual success.

Close