PAM is short for polyacrylamide. Water-soluble varieties of anionic and non-ionic PAM can be quite effective for bubble juice. In September 2018, RogerH published a blog entry detailing successful trials with PAM (which you can read here). Others, including Edward, have replicated his results. Important PAM Variety Note. Only anionic and nonionic varieties of PAM are non-toxic and environmentally safe. Molecular weight: Per RogerH, the molecular weight of the PAM may approach or even exceed 10 million!
How does it compare? As of this writing (October 2018), there have not yet been enough experimentation to know how well this ingredient compares to PEO , HEC or guar gum in terms of effectiveness. But the reports so far are quite promising.
It can be effective at very low concentrations (similar to PEO). In Roger's initial report, he reports that as little as 0.01 grams per liter of bubble juice is effective.
PAM Variety and Solubility. For bubble juice, you need to use a water-soluble variety of polyacrylamide. Many varieties of polyacrylamide are not water-soluble. Such versions are unsuitable for bubble-making. Their grains swell into large insoluble gel globs that do not dissolve.
The variety that RogerH has explored is used as a soil amendment for helping water retention. He notes that polyacrylamide is a very stable molecule which may make it less likely to degrade in storage than PEO.
Roger recommends making a 0.1% PAM solution and adding this to a detergent/water mix (and adjusting the pH as one does for optimal bubble juice). These instructions are based on the variety of PAM used by RogerH which is marketed as "Water Retention Granules" from The DIrty Gardener (see notes elsewhere on this page for information about getting the correct version). For different varieties, you may need a different amount.
To make 0.1% PAM solution:
- Add 1 gram of PAM crystals to an empty container (jug or mixing bowl).
- Add 1 liter of water to the container AFTER adding the PAM crystals. (Technically, you should use 999 grams water to make this a truly 0.1% solution but 1000 grams -- 1 liter -- is close enough).
- Let it stand for about 8 hours then give it a good stir (he recommends a whisk)
- Let it stand for another 8 hours and give it a thorough mixing until you have a uniform solution
To make bubble juice:
- Use 10 to 100 grams (or ml) of the PAM solution
- Add enough water to bring the amount of liquid to one liter
- Add your preferred amount of detergent
- Adjust the pH as you usually would
Bubble-Juice Recipe. The PAM Bubble Juice recipe page has some great recipes for PAM-based bubble juice.
Higher Concentration PAM solutions. It is easy to mix up a 0.1% solution with minimal fuss. It sees that one can go as high as 3 grams in 1 liter of water but going to a higher concentration seems problematic with hand stirring. Even at 3 grams some attention must be made to make sure that the solution is uniform. Otherwise, you get a very viscous core that is nearly impossible by hand to get to mix with the rest of the solution. Roger noted that 5 grams in 1 liter was impossible to get uniform when stirring by hand.
Volume/weight equivalence: In one trial with The Dirty Gardener Water Retention Granules, 1 teaspoon (5 ml) of the granules weighed 4.4 grams. We recommend using weight rather than volume for accurate measurement. If that isn't possible, 1/4 packed teaspoon per 1 liter of water should create a approximately 0.1% solution suitable for use.
What PAM Should I Use?Edit
Polyacrylamide comes in a lot of varieties. For making bubble juice, you need a water-soluble variety. The most easily found varieties seem to be the INSOLUBLE variety which can be found in garden stores and are intended to store and release water. The desirable water-soluble PAM is often sold as a "tackifier" for stabilizing mulches and soil. It is also used at construction sites and on dirt roads to suppress dust. RogerH notes that it can often be found at farm supply shops. His local shop sells 15 pound bags for $60! (That is enough for a lot of bubble juice. Since 0.4 gram is enough for one gallon of bubble juice.) Here are some PAM varieties suitable for bubble-making.
- Dirty Gardener's Water Retention Granules. Water Retention Granules from The Dirty Gardener are what Roger has been using. Edward received some water-insoluble PAM when placing his order in September 2018. The Dirty Gardener folks happily replaced the insoluble PAM with the soluble version and provided this advice to make sure that you get the water-soluble PAM when placing your order. TO BE SURE YOU GET THE RIGHT POLYACRYLAMIDE FROM THE DIRTY GARDENER. Order Water Retention Granules and BE SURE to add a note when ordering that you want the fine granules that are water soluble. Their water-soluble PAM has the texture of granulated sugar and tne the insoluble PAM is quite a bit more coarse. Per davidkni, this PAM is anionic.
- FLOPAM. Someone wrote to me from the UK about a version with which they are having good luck: "'FLOPAM' an913 (food grade) from SNF UK. Dissolves quickly with agitation only at 1 gram per liter."
- Flocloc by Profile. Anionic PAM with minimum molecular weight of 18M.
Other suitable products. There are certainly other sources of water-soluble PAM. We have had a lot of questions about whether other versions of polyacrylamide work. We will products known to be effective as we find out about them. Roger has recommended that you buy the smallest amount possible and determine if it is water soluble before investing in a large quantity.
To determine if your PAM is water soluble: add something like 1 liter of water to 1 gram of PAM crystals -- or 500 ml of water to 0.5 grams of PAM, let it sit for 8 hours. Stir vigorously. Let it sit for another 8 hours and stir vigoursly and see if the result is a uniform solution or if you just have chunks (which might be transparent) suspended in water. If it still isn't uniform, repeat the stir and wait process a few more times before completely giving up. Try pouring it through a sieve, if it has dissolved then it will all go through and if it hasn't then the water will go through and the sieve will be full of little lumps of gel. Edward notes: While the soluble PAM may take a while to fully dissolve, it will cause a noticeable viscosity increase if you stir the solution after only a few minutes. The insoluble PAM "crystals", on the other hand, swell and become invisible and do not change the viscosity at all.
Are there ways to speed up the hydration? Good question. I don't know at this stage. I am curious as to whether heating up the water at some point might speed things up, but I haven't tried it yet. RogerH3 adds: I've tried mixing PAM at 1 g/L using a heated magnetic stirrer (see pic). Starting from cold the PAM was nicely dissolved and uniform in less than an hour. Starting with close to boiling water it looked good in a little under 20 minutes. So if you are in a hurry: heat the water to near boiling, pour half of it into a bowl, sprinkle in the PAM, add the rest of the water, mix every few minutes with an eqg whisk until it's uniform (about 15 to 20 minutes).
Stability and MiscellanyEdit
PAM seems to be more stable than PEO both in dry form and in solution. RogerH has found that even without a preservative, a water and PAM solution maintained its viscosity over a much longer at room temperature than a similar PEO solution. This was true with and without a preservative (Paraben).
Davekni reports that PAM also seems not to be affected by high-shear mixing in the way that PEO is. So while using a blender will ruin PEO, it does not seem to ruin a PAM solution. (See Davekni's comments in the discussion/talk section below.) More data points are needed. But if this conclusion holds up, this may simplify the procedure for getting nicely uniform PAM solutions.
Report Your Results!Edit
This is a new ingredient. Please share the results of your experiments with us!