This article lists outstanding questions related to soap bubbles. If you have done experiments related to any of these questions, please either update this page, add your notes in the comments, or contact us. If you are looking for experiments to try, please take a look at this list -- perhaps, you can experiment and share your results via the wiki!
See also: In-progress Investigations
- pH: Baking powder vs. baking sod/citric acid. There have been mixed reports from the field as to what works best for people. A study should be made comparing the behavior of bubble juice with the pH lowered via baking powder, baking soda+citric acid, citric acid alone, vinegar. The juice should have the pH adjusted to particular pH and other than the pH adjusters, the juices should be identical. An 18:1 or 20:1 guar-based juice would be a good juice to use although any basic juice base would be acceptable.
- pH: Baking soda/citric acid vs. sodium citrate. Can we do some experiments that demonstrates that adding sodium citrate has the same effect as adding baking soda and citric acid separately. While there would be no difference if the bs/ca were added to distilled water, the question remains whether baking soda and/or citric acid might be reacting on their own with minerals in the water or ingredients of the detergent. While it seems likely that the two methods are equivalent, it is not certain as their have been some reports about solutions being different depending on when the baking soda and citric acid are added. DECEMBER 2013: There is evidence (at least with Charmy) that Sodium Citrate is not as helpful as baking powder or baking soda/citric acid. Edward found (see blog entries) that there was no benefit to adding sodium citrate in cases where the juice improved noticeably with amendments that lowered the pH.
- pH/storage/concentrates. Would a concentrate such as eGoo be harmed if it were acidified enough so that the diluted juice were in an ideal pH range. Edward notes that about 0.6 grams of citric acid added to 1 gallon of diluted eGoo juice yielded a pH of about 7.6. That would amount to about 0.6 grams citric acid per 236 grams of concentrate. 0.75 grams would probably be ok for a 15:1 water:concentrate ratio.
- pH. Do different detergents demonstrate different bubbling potentials at different pHs?
- pH. What are the best methods for raising/lowering/buffering the pHs of bubble juice?
- Charmy/Japanese Laundry Starch. Adding baking powder to Hisao Oono's Charmy/PVA Laundry Starch recipe yielded poor results . Is the problem the baking powder or the pH? Try using citric acid or baking soda+citric acid to lower th pH and use half the amount of detergent called for in Mr. Oono's Recipe .
- Glycerine/Dilution. Re-evaluate influence of glycerine when present in large amounts. Look at solutions with 10%/20%/30% glycerine by weight. Compare to solutions with no glycerine. Use color profile to compare 20:1 water:detergent with glycerine added to make up 25% of weight to a solution that 20:1 water+glycerine:detergent with the amount of glycerine and detergent held constant.
- Glycerine/pH. Why is there such a large discrepancy in the quoted pH values of glycerine (values quote range from 5.5 to 7.0 to 10.0)? Edward Spiegel's testing indicates that glycerine has a pH of about 5.6. [UPDATE SEPT 2010: Edward has measured and received reports about several different brands of glycerine all falling in the range 5.6 to 7.3]
- Aging solutions. When does aging solutions for a day or more benefit them?
- Aging solutions. Is it important to age solutions in an open container to evaporate volatiles in the detergent?
- J-Lube. Is the optimal amount of J-Lube related to the amount of water in the final bubble juice or the amount of detergent or something else?
- Surgilube/KY-Jelly. How do these amendments differ in their impact on a water/detergent mix? [ AN ANONYMOUS POSTER WROTE: UPDATE DEC 2012: Both in cold humid NY and hot dry LA I found KY to be a positive addition testing 2oz of it in a 12 cup water and 1 cup ultra dawn mix with bubble thing slide wands, verses the same mix with no KY. It always performed better with the KY (if mixed right with hot water) making the bubbles more self healing (aka wobbly). The optimal amount? I do not know.] [EDWARD REPLIES 12/9/2012: I apologize if the question wasn't clear. The question isn't whether KY Jelly makes a difference. As noted elsewhere on the wiki, KY is an effective ingredient-- the question is what is the DIFFERENCE between KY Jelly (and its knock-offs) and Surgilube in their effect -- both as primary and secondary ingredients? What disambiguates them.
- Surgilube/KY-Jelly. How do these amendments differ in their interaction with J-Lube?
- Surgilube/KY-Jelly/Glycerine. Are there synergies between lube and glycerine? Mixes of Dawn Ultra, tap water, KY-Jelly (or a generic knock-off), and glycerine seem to have radically better characteristics than mixes that leave out either lube or glycerine. More research needs to be done to see if this is actually true.
- Surgilube/KY-Jelly. Is the optimal amount of lube related to the amount of water in the final bubble juice or the amount of detergent or something else?
- Detergent/amendment interaction. Due differences in size potential of detergent and water combinations translate to similar potential differences when amendments such as J-Lube/Surgilube are added -- or do such amendments even the playing field (at least to a degree).
- J-Lube, etc. What is the optimal ratio of J-Lube/Surgilube?
- Water. How much variation in bubble potential is there in tap water based solutions?
- Tri-String Wands. To what extent does the string's absorbency benefit the size of the bubbles created and/or the number of bubbles per dip?
- Tri-String Wands.To what extent is the maximum bubble size a function of bubble juice, the wand opening size and the absorbency of the wand material?
- Detergent. Could some detergents be improved by "cooking" either before adding amendments or after? In partcular, would heating remove the noxious odor from Dawn Direct Foam.
- PVA/Starch. Some Japanese laundry starch which is based on polyvinyl alcohol (pva) and modified rice starch is reported to be a valuable additive to bubble juice that improves color and strength. PVA on its own does not seem to do this. Articles about the chemistry of the modified rice starch/pva combination indicates that the qualities may be due to either synergy between the pva and starch OR that the modified rice starch itself is responsible. Also, in reading, it is clear that for starch to be at its most useful it needs to be cooked. Question: will a pva/cooked starch mix benefit bubble juice?
- Guar Gum/Borax cross-linking. Guar Gum solutions mixed with a small amount of borax solution is known to crosslink (which can be used to create a really nice slime). Can this cross-linking benefit bubbles?
- 'Dilute solutions' mixing order. Does it matter with the polymer is added to the water and then the detergent added or if the detergent and polymer are mixed before being added to the water?
- juice temperature if the juice is cooled below ambient temperature, is longevity improved? See http://soapbubble.wikia.com/wiki/Thread:5861#5
Film Thickness, Color, DilutionEdit
- Does bubble size influence color/film thickness other than due to overstretching?
- Do comparision of film thickness achieved with different size tri-strings and rigid hoops
- Rigid hoops: does absorbent winding influence film thickness of resulting bubbles.
Ingredient Questions and Things to ExploreEdit
Ethulose? - This recipe suggests using Ethulose along with WSR301. Does the Ethulose make a difference?
Edward (note to self): Look at notes from Tomasz Borkowski about PVP and sodium PCA, PVA and Sodium Hyaluronate. He suggests trying PvP and PCA together. Claims that it increases longevity.