For The Love of Bubbles: The Gateway Concoction to Chemistry And The Universe

For the first week's wacky science class, I was supposed to teach kids the science of bubbles. The operative word here is 'supposed', because the kids were familiar with bubbles. Very, messily familiar.

But they weren't exactly concrete on how they could be strengthened, prolonged, or weakened. So I did have something to offer!

As a scientist at heart, I like learning about the explanations behind phenomena. So when it came to how bubbles could be unpoppable - or more realistically, stronger - I wanted to be able to explain to these little kids the real reasons behind it. Just saying the addition of corn syrup wasn't enough. I had to get these kids thinking, and that meant I had to know which direction to point them in. So I got searching.

Searching for answers on Youtube brought me to a kid-friendly video that obviously belonged to a channel dedicated to science for kids. I'm a grown woman, so I rolled my eyes at the thought that I should watch it. But hey, let's see how these people and their mouse gave the explanation. Research into how to turn the lecture kid-friendly, perhaps?

Their explanation was a bit lackluster: They likened the membrane of a bubble as a sandwich, with the corresponding layers of air, soap, water, soap, and air again. Water is trying to find a hole in the membrane to evaporate, and once it does - pop goes the bubble. Adding corn syrup to the mix thickens the layer of soap molecules, making water less able to find a hole and evaporate.

To show this off, they compared the timing of a normal soap-and-water mixture bubble to the timing of a mixture with corn syrup thrown in. The bubble with corn syrup, predictably, stayed holding longer and popped later.

A worthy explanation for the kids. Simple with evocative imagery, perfect for their tiny attention spans. But I wasn't satisfied. Was this the explanation used everywhere, or is there more to it? Is a bubble really composed of layers, like a sandwich?

Actually, what got me thinking was the water finding a hole in the soap shield and evaporating, with the air accompanying its escape to produce the pop. Is that really how it goes?

My speciality is in neuroscience, not bubbles. Excuse my curious mind, but sometimes something simple can be surprising.

So I looked into it a bit more. Less youtube, more internet. A little bit of ChatGPT, which can be helpful in finding sources for things.

Disclaimer: I'd never let it tell me just straight up statements without the evidence for it; the scientific studies and websites and sources it derived the information from are very important to me.

What I got is more, shall we say, to my standards? Something a bit more complex, covering the unspoken questions:

Water alone has a high surface tension due to the water molecules bonding with one another via hydrogen bonds, and that high surface tension means it's real easy to break. It's inflexible and not stretchy, so any disruptive force applied to the bubble will break it quick and easy. Not to mention, water molecules with energy will try to fly away (evaporate), so it's not even outside disruptive forces that force the bubble to break. Physics is in charge here.

Add soap to the mix and it veers more towards chemistry via the interaction of molecules. Soap has been historically made from animal fats, though nowadays the fats can also be derived from plants and synthetic ingredients - the latters commonly marketed as more organic, natural, or better-for-you. I've got things to say about that in my master's thesis, located on my website and at the Johns Hopkins online library.

These soap fats are composed of lipids, which brings bubble science to the molecular level. Lipids are made of two parts - a head and a tail - with the head loving water and the tail hating it. Put these lipids in a container with water, and one part of the molecule is happy while the other isn't. It's unnatural; water shouldn't be surrounding them.

Thus they will spontaneously form into a (either single or double) layer with heads out and tails in, to keep the tails away from the water. As the universe loves maximum efficiency with minimal energy, the shape these lipids form themselves into is the circle; it maximizes tail shielding while keeping hydro-loving heads in contact with water.

This part can be boring for people. Hell, it's basic science. But is amazes me because of one simple fact: the lipids aren't even alive.

Chemistry just does that; going into energetically-favorable states for the system to be in the smallest-possible energy state. There's no sentience to it. No one is delivering or obeying orders, no one is making a decision and taking action. It's the laws of the universe at work on the molecular scale. It can even be harnessed into mathematical formulas, like Gibbs Free Energy. It happens because things in the universe go towards maximum entropy and this creates it. It's on a teeny tiny scale, and it's all mindless.

Biology holds my heart, but chemistry can be really cool.

Back to what I was saying. Water molecules are trapped in this double-layer cage of lipid molecules. Have enough a ratio of water-to-lipids, and you get the liquid solution that is soap. Blow some air, and the water molecules become a dynamic wall as well.

The bubbles that you get from this soap last longer than the just-water-bubbles because of the ease in surface tension. The water molecules can move around, more trapped, with a lower chance of flying out. The lipid layer is flexible because of the high movement of the water molecules; shifting, sliding, and rearranging in accommodation with the water.

But the lipid layer isn't infallible. It's not perfect. And there are still other universal forces at play, like gravity. The water in the bubble is flowing downwards - draining - and the lipid molecules are moving laterally to adjust and cover the areas left behind or made by the water molecules. Give it enough time, water flowing downwards faster than lipids are moving, and this lipid layer thins enough and is slow enough for water to break through. That water has flown the coup and the water molecules and lipid molecules are no longer holding hands.

The laws of physics and thermodynamics acts with free energy and surface tension. Surface tension goes to minimize surface area, pulling water away from the rupture and expanding the hole. Air rushes in, adding to the bubble pressure and forcing water molecules out. The remaining film of attached water molecules shrinks and retreats to reduce free energy. Eventually the whole film collapses, the bubble pops, water and lipid molecules fly free, and entropy is increased in the universe. All is as it should be. And I haven't even gotten into the quantum mechanics of this.

This quick popping process is called a runaway collapse, for those invested in vocab.

Quantum mechanics, chemistry, free energy and entropy go into making a bubble. Then those laws combined with thermodynamics make it collapse. It's not even a strong bubble.

For kids, the excitement comes when you add in corn syrup.

A bubble is strengthened if whatever is added slows the thinning of the lipid layer, stabilizes the film of water and lipids, and reduces evaporation of the water. Corn syrup does the latter by increasing the viscosity - thickness - of the water layer.

This is due to corn syrup's ingredient: the sugar glucose. A simple sugar, with many polar hydroxyl groups, which attracts the polarity of water's molecules and forms hydrogen bonds. Because of these many polar groups on one molecule, many water molecules can attach to one glucose molecule. Many glucose sugars, many water molecules, and many hydrogen bonds later, a network is formed. For water molecules to escape this network and evaporate, these numerous hydrogen bonds must be broken. This means more energy has to be put into breaking the bonds.

That doesn't mean such energy has to be big. Among the water and glucose molecules, energy is used and expelled to break and made the hydrogen bonds. That's why sugar can be dissolved in water.

But this does mean the overall solution is thicker, as the water molecules cannot flow as easily when they are constantly being caught by sugar molecules. The water molecules still attach to the water-loving heads of the lipid molecules, forming the layers of the bubble. But the water-and-sugar solution makes a downward flow occur slower, allowing the lipids more time to shift with the molecules and keep their shell intact. Thus, the whole runaway collapse process of before just works in slower motion, allowing the kids to make the bubble grow or prolong its life longer.

It was another experiment for the kids on whether adding cornstarch to the mix would make the bubbles last even longer. I thought it would. After all, cornstarch is also made of sugar, right?

And this is where chemistry becomes even more interesting. Yes, cornstarch is composed of sugars, but it's not the same simple sugars as corn syrup. It's those long chains of sugars - polysaccharides like amylose and amylopectin - that make a good difference. It's because of their molecular structure.

They carry many hydroxyl groups similar to glucose, attracting water molecules, but in this case the key issue is accessibility. The sugar chains are folded and packed tightly, so they form internal hydrogen bonds.

It's like trying someone trying to grab an object from you, so you fold yourself up into a ball on the ground. They have less accessibility to that object, thus less chance of capturing the object.

This means the water molecules are competing against each other to surround the chains and make those bonds - grabbing that object - which lowers the chances of external hydrogen bonding (bonding to the hydrogen atoms).

In simple terms, the sugar chains won't dissolve well into the water solution. There will be more clumps, so the water-and-sugar solution will not be as flexible. This rise in surface tension and inflexibility means that a bubble can't form or can't stay in form for long, because the lipids are going over a rough surface where water molecules may or may not contact them and each other and the sugar chains. It's a whole network of unlikelyness.

In keeping with the laws of the universe, unlikelyness means it won't happen often. And the elements of the universe don't have the sentience to gamble.

I didn't even get to the quantum mechanics. I didn't talk about the quarks, protons, electrons, energy levels, or probability clouds of oxygen and hydrogen atoms, why they even become water molecules in the first place. This is so much already, and it's just a concoction of water, soap, and corn syrup or cornstarch. It's just chemistry with physics and thermodynamics. It's all mindless and seemingly simple.

And yet, mindless bubble science has led to big advances in multiple fields.

Various fields like industry, medicine, biology, environmental and chemical engineering, and once again physics and fundamental science are touched by bubbles and their layers. Ice cream, whipped cream, soaps, detergents, and cosmetics - just to name the stuff you'd find in your house. Complicated things with microbubbles like drug delivery, imaging, and cell research. Things that advance our knowledge of ourselves and the universe at large.

I didn't get to stress this to the kids, but that was the first lesson of wacky science. The first lesson that could lead kids into thinking about the mechanics of the whole world.

In doing this research, I regret that I couldn't tell them more. One hour is not enough time, especially when kids are more focused on blowing and popping bubbles than the how and why it can happen. I hope this explanation serves to help other teachers and kids, and shows why bubbles are the gateway to the universe.

Citations for the science (not in alphabetical order):

1. “Soap Bubble.” Wikipedia, https://en.wikipedia.org/wiki/Soap_bubble. 
2. “Soap Film.” Wikipedia, https://en.wikipedia.org/wiki/Soap_film. 
3. Pugh, Robert J. Soap Bubbles and Thin Films. Cambridge University Press, 2016. https://resolve.cambridge.org/core/services/aop-cambridge-core/content/view/42041F3177C2ED0B9F3FB1A2C8539FCE. 
4. “The Life of a Surface Bubble.” PMC, https://pmc.ncbi.nlm.nih.gov/articles/PMC7957579/. 
5. de Gennes, Pierre-Gilles, et al. Capillarity and Wetting Phenomena: Drops, Bubbles, Pearls, Waves. Springer, 2013. 
6. Shen, Li, et al. “Transient Structures in Rupturing Thin Films.” arXiv, 2019. 
7. Seiwert, Jacopo, et al. “Extension of a Suspended Soap Film.” arXiv, 2013. 
8. Andrieux, Sébastien, et al. “Microfluidic Thin Film Pressure Balance.” arXiv, 2020. 
9. Su, Jun, et al. “Investigation of the Formation Process of Soap Bubbles.” arXiv, 2017. 
10. Schwarz, H. A. (referenced in bubble minimal surface theory). Discussed in: Soap Bubble, Wikipedia. 
11. Plateau, Joseph. (Plateau’s laws, discussed in foam physics). See: Soap Bubble, Wikipedia. 
12. Israelachvili, Jacob. Intermolecular and Surface Forces. Academic Press, 2011. Intermolecular and Surface Forces. Elsevier, 2011, https://doi.org/10.1016/c2009-0-21560-1. 
13. Atkins, Peter, and Julio de Paula. Atkins’ Physical Chemistry. Oxford University Press. Atkins, Peter, and Julio de Paula. PHYSICAL CHEMISTRY. 2006, nowgonggirlscollege.co.in/attendence/classnotes/files/1621583343.pdf.
14. Adamson, Arthur W., and Alice P. Gast. Physical Chemistry of Surfaces. Wiley. 
15. Tanford, Charles. The Hydrophobic Effect: Formation of Micelles and Biological Membranes. Wiley, 1980. CHAPMAN, D. “The Hydrophobic Effect: Formation of Micelles and Biological Membranes (2nd Edition).” Biochemical Society Transactions, vol. 9, no. 1, Portland Press Ltd., Feb. 1981, pp. 178–78, https://doi.org/10.1042/bst0090178. 
16. Myers, Drew. Surfactant Science and Technology. Wiley, 2005. Myers, Drew. Surfactant Science and Technology. Wiley, Sept. 2005, https://doi.org/10.1002/047174607x. 
17. Rosen, Milton J., and Joy T. Kunjappu. Surfactants and Interfacial Phenomena. Wiley, 2012. Rosen, Milton J., and Joy T. Kunjappu. Surfactants and Interfacial Phenomena. Wiley, Jan. 2012, https://doi.org/10.1002/9781118228920. 
18. Nagarajan, R., and E. Ruckenstein. “Theory of Surfactant Self-Assembly.” Langmuir. Nagarajan, R., and E. Ruckenstein. “Theory of Surfactant Self-Assembly: A Predictive Molecular Thermodynamic Approach.” Langmuir, vol. 7, no. 12, American Chemical Society (ACS), Dec. 1991, pp. 2934–69, https://doi.org/10.1021/la00060a012. 
19. Safran, S. A. Statistical Thermodynamics of Surfaces, Interfaces, and Membranes. Safran, Samuel A. Statistical Thermodynamics of Surfaces, Interfaces, and Membranes. CRC Press, 2018, https://doi.org/10.1201/9780429497131. 
20. Ball, Philip. Water as an Active Constituent in Cell Biology. Chemical Reviews. Ball, Philip. “Water as an Active Constituent in Cell Biology.” Chemical Reviews, vol. 108, no. 1, American Chemical Society (ACS), Dec. 2007, pp. 74–108, https://doi.org/10.1021/cr068037a. 
21. Chaplin, Martin. “Water Structure and Science.” http://www1.lsbu.ac.uk/water/ martin.chaplin @btinternet.com, martin chaplin. “Water Structure and Science.” Github.io, 2020, vitroid.github.io/water-science/water/index.html. 
22. Franks, Felix. Water: A Comprehensive Treatise. Nih.gov, 2026, catalog.nlm.nih.gov/discovery/fulldisplay/alma991072123406676/01NLM_INST:01NLM_INST. 
23. Nelson, David L., and Michael M. Cox. Lehninger Principles of Biochemistry. “Lehninger Principles of Biochemistry, 8th Edition | Macmillan Learning US.” Macmillanlearning.com, 2021, www.macmillanlearning.com/college/us/product/Lehninger-Principles-of-Biochemistry/p/1319228003. 
24. Berg, Jeremy, et al. Biochemistry. “Biochemistry, 10th Edition | Macmillan Learning US.” Macmillanlearning.com, 2023, www.macmillanlearning.com/college/us/product/Biochemistry/p/131933362
25. Telis, Valdemiro R. N., et al. “Viscosity of Aqueous Carbohydrate Solutions.” International Journal of Food Properties. “Viscosity of Aqueous Carbohydrate Solutions at Different Temperatures and Concentrations.” International Journal of Food Properties, 2026, https://doi.org/10.1080//10942910600673636. 
26. Morris, E. R. “Rheology of Carbohydrate Solutions.” Food Hydrocolloids. Morris, Edwin R. “Rheological and Organoleptic Properties of Food Hydrocolloids.” Food Hydrocolloids, Springer US, 1994, pp. 201–10, https://doi.org/10.1007/978-1-4615-2486-1_31. 
27. Rao, M. A. Rheology of Fluid and Semisolid Foods. Rao, M. Anandha. “Rheology of Fluid, Semisolid, and Solid Foods.” SpringerLink, Springer US, 2026, https://doi.org/10.1007-978-1-4614-9230-6. 
28. Spagnuolo, Paolo, et al. “Hydrogen Bonding in Sugar Solutions.” Journal of Physical Chemistry. Paolantoni, Marco, et al. “Hydrogen Bond Dynamics and Water Structure in Glucose-Water Solutions by Depolarized Rayleigh Scattering and Low-Frequency Raman Spectroscopy.” The Journal of Chemical Physics, vol. 127, no. 2, AIP Publishing, July 2007, https://doi.org/10.1063/1.2748405.
29. Buléon, Alain, et al. “Starch Granules: Structure and Biosynthesis.” International Journal of Biological Macromolecules. Buléon, A., et al. “Starch Granules: Structure and Biosynthesis.” International Journal of Biological Macromolecules, vol. 23, no. 2, Elsevier BV, Aug. 1998, pp. 85–112, https://doi.org/10.1016/s0141-8130(98)00040-3. 
30. Tester, Robert F., et al. “Starch Structure and Properties.” Food Hydrocolloids. 
31. Jane, Jay-Lin. “Starch: Structure and Properties.” ResearchGate, unknown, 2003, pp. 81–102, www.researchgate.net/publication/329162462_Starch_Structure_and_properties. 
32. French, Dexter. “Organization of Starch Granules.” Advances in Carbohydrate Chemistry.
33. Rundle, R. E., and Dexter French. “The Configuration of Starch and the Starch—Iodine Complex. II. Optical Properties of Crystalline Starch Fractions1.” Journal of the American Chemical Society, vol. 65, no. 4, American Chemical Society (ACS), Apr. 1943, pp. 558–61, https://doi.org/10.1021/ja01244a018. 
34. Vrij, A. “Possible Mechanism for the Spontaneous Rupture of Thin Films.” Discuss. Faraday Soc. Vrij, A. “Possible Mechanism for the Spontaneous Rupture of Thin, Free Liquid Films.” Discussions of the Faraday Society, vol. 42, Royal Society of Chemistry (RSC), 1966, p. 23, https://doi.org/10.1039/df9664200023. 
35. Mysels, Karol J., et al. Soap Films: Studies of Their Thinning. de Vries, A. J. “Soap Films, Studies of Their Thinning and a Bibliography.” Journal of Colloid Science, vol. 15, no. 6, Elsevier BV, Dec. 1960, pp. 585–86, https://doi.org/10.1016/0095-8522(60)90062-3. 
36. Exerowa, Dimiter, and Penka Kruglyakov. Foam and Foam Films. “Foam and Foam Films - Theory, Experiment, Application.” Studies in Interface Science, Elsevier, 1998, https://doi.org/10.1016/s1383-7303(98)x8001-4. 
37. Bergeron, V. “Forces and Structure in Thin Liquid Films.” Journal of Physics: Condensed Matter. Bergeron, Vance. “Forces and Structure in Thin Liquid Soap Films.” Journal of Physics: Condensed Matter, vol. 11, no. 19, IOP Publishing, Jan. 1999, pp. R215–38, https://doi.org/10.1088/0953-8984/11/19/201. 
38. Sirsi, Sanjiv R., and Mark A. Borden. “Microbubble Contrast Agents.” Ultrasound in Medicine & Biology. 
39. Klibanov, Alexander L. “Ligand-Carrying Gas-Filled Microbubbles:  Ultrasound Contrast Agents for Targeted Molecular Imaging.” Bioconjugate Chemistry, vol. 16, no. 1, American Chemical Society (ACS), Dec. 2004, pp. 9–17, https://doi.org/10.1021/bc049898y.
40. Tsutsui, Jeane M., et al. “The Use of Microbubbles to Target Drug Delivery.” Cardiovascular Ultrasound, vol. 2, no. 1, Springer Science and Business Media LLC, Nov. 2004, https://doi.org/10.1186/1476-7120-2-23. 
41. Tong, Baocai, et al. “CO2 Microbubbles Enhanced Oil Recovery in Fractured Reservoirs.” Geoenergy Science and Engineering, vol. 253, Elsevier BV, Oct. 2025, p. 213976, https://doi.org/10.1016/j.geoen.2025.213976. 
42. Brennen, Christopher. Cavitation and Bubble Dynamics. Oxford University Press. Brennen, Christopher, and New Oxford. Cavitation and Bubble Dynamics. 1995, brennen.caltech.edu/INTBub/bubbook.pdf.
43. Leal, L. Gary. Advanced Transport Phenomena: Fluid Mechanics. Leal, L. Gary. Advanced Transport Phenomena. Cambridge University Press, June 2007, https://doi.org/10.1017/cbo9780511800245.