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NOTE TO THE READER-August 2017: I have fixed a few typos recently reported by Grandpop Bubbles. This blog dates from a period when I was first coming to understand the relationships between longevity, dilution, and color. This is a snapshot of where my understanding was at the time and does not necessarily represent my current best understanding (which is reflected in the wiki articles themselves).

(INCOMPLETE) Not quite a year ago, I started exploring the impact of water:detergent ratios on bubble juice and posted my first blog entry about the topic . The explorations were eye-opening, at least to me. I had intended to have frequent blog entries with updates as my explorations progressed. I never managed to do that. This entry summarizes much of what I have learned during that time period. This information will be the basis of some proper wiki articles, but my thoughts are not yet organized enough for that article. In the meantime, it seemed like it would be worthwhile to gather together the relevant information in one place as I think that it is important info for any serious bubblehead to know.

Dilution, Micelles, and Surface Tension[]

Dilution, Color, and Film Thickness[]

Viscosity, Strength and Film Thickness[]

Even though it is not really a detergent concentration issue, it is worth noting that a bubble solution's thickness (viscosity) is not necessarily related to the resulting film thickness. Many people (even experienced bubblers) have the intuition that a viscous, thick bubble juice results in bubbles whose walls are thick and strong. While there are cases where viscous solutions yield bubbles with relatively thick bubble walls, it is more common for changes in the viscosity to have no practical impact on the bubble wall thickness.

Viscosity infuences the flow of a solution, but the impact on film thickness depends on the actual ingredients. In its usable range, PEO seems to have no impact on the film thickness. The same is more or less true of HEC in its typical concentrations. Guar gum is unusual in that it can have a quite noticeable impact on the bubble thickness. Guar-heavy mixes result in films that indicate changes in the wall thickness. (It must be noted that it is possible that the guar is impacting the solution's index of refraction more than the actual thickness, but I have been told that this is not likely.)

Photos of bubbles made with different dilution solutions[]

The pictures below were taken during the same fairly short session. The lighting conditions changed only minimally during the brief session. So, the color differences are the result of the differences between the bubble juices. [EDWARD: find more 25to1 pictures from this session. ALSO add gallery of photos from 2012 03 23 session which has 20to1;45to1;13to1]

Click on the photos to see them at a larger size. The important details aren't obvious in the thumbnail images.

 

 See also: this blog entry illutstrates color differences between HEC solutions at dilutions of 16:1, 20:1 and 24:1]

Photos illustrating impact of dilution on colors as bubbles stretch[]

Click on the photos to see them at a larger size. The important details aren't obvious in the thumbnail images.

 

Above: A tube created with a 16-to-1 water:detergent ratio. Notice how the colors become muted just before the tube has stretched to the breaking point.

 

Above: A tube created with a 25-to-1 water:detergent ratio guar-based juice. Notice that the colors change as the tube stretches but are still quite vibrant even as the tube has stretched to the breaking point.

Impact on Multi-Bubble Wand Dips[]

Another notable difference between more and less dilute solutions is the tendency when many bubbles are made from the same wand dip for the later bubbles to be less colorful than the early bubbles. This tendency is often especially obvious when using a high-capacity garland wand. When the bubble juice has a relatively large amount of detergent, the last bubbles will often be colorless or almost colorless. With a relatively dilute solution (if it is dilute enough), even the bubbles at the end of the dip will be quite colorful.

[EDWARD: NEED VIDEO OR PHOTOS TO DEMONSTRATE]

Color Stability[]

Impact of Dilution on Size Potential[]

Impact of Dilution on Longevity[]

The relationship between dilution and bubble longevity is surprising to many people -- even experienced bubblers. The relationship is not linear. The following observations are based on using simple longevity testing apparatus using dishwashing liquid or a similar products as the source of surfactants. It may not apply to pure water:surfactant mixes.

If you start with an undiluted product and run a longevity test, you are likely to get a local maximum with the the longevity of the bubbles going down as the solution becomes somewhat more dilute. However, at some point, which varies according to the detergent, the longevity starts to rise again as the solution becomes even more dilute. The longevity will continue to rise with dilution; however, at some point a few intereesting things happen which are probably related to Critical Micelle Concentration (CMC) (note august 2017, while these are related to concentration it seems not to be related to the CMC):

  • the bubbles become increasingly color stable with little or no color drain even after 60 seconds whereas at lower dilutions all the color might drain from the bubble at 30 seconds -- depending on the mix.
  • when the solutions become very very dilute (somewhere around 60 or 70 to 1 with Dawn Pro), the bubbles become glossy and colorless which indicates that the soap film is very thick. (Note: very thin films are colorless but not glossy).
  • when the solutions become very very dilute (for a particular detergent), the failure rate trying to form a bubble becomes very high. This dilution often corresponds to the dilution at which the bubbles start to be colorless (due to their thick walls). For Dawn Pro, this happens at dilutions upwards of 70 to 1.

During such an experiment, one notices that at low dilution bubbles may have a tendency exhibit a color drain (from top down) and become transparent ghost bubbles (if the air quality is good) that are so thin that they are not even glossy. As the dilution increases, the length of time that precedes the color drain will tend to increase. One will also notice that the colors may be most vibrant in particular dilution ranges.

By observing both the longevity of the bubbles and their colors, you can find the useful dilution range. Some in-field testing of different dilutions (with different amounts of polymer) is needed to dial in the range.

Impact of Dilution on Bubble-Friendliness[]

Dilution and Polymer Concentrations[]

Related[]

Color and Film Thickness - article illustrating the relationship between film thickness and color. 2012 03 Dilute Solution Explorations (first entry about this topic)

2012 Nov. Giants Random Thoughts (illustrates the color differences between 16:1, 20:1, and 24:1 HEC-based mixes).

Dilute articles category

Dilution articles category

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