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This article describes a method for determining what we are calling the NMEC for a batch of PEO. NMEC stands for Nominal Minimum Effective Concentration. It is the concentration required to turn water:detergent into an at-least minimally friendly solution.

WHY[]

PEO is a very important bubble juice ingredient. It is the main ingredient in PolyOx WSR-301 and J-Lube. Over the past few years, it has become clear that the amount used in recipes is quite variable due to both its long-term instability and personal preference. This instability accounts for much of the variation that one sees in recipes that contain these ingredients--and often accounts for what individuals believe is changing preference (when what is really changing is the PEO strength).

It has become obvious that it would be useful to have a way of objectively determining the strength of one's PEO using simple equipment that most bubble brewers have on hand.

Interestingly, "degraded" PEO is often preferred to full-strength PEO because it results in a less stringy bubble juice even when the amount is adjusted for the potency loss.

As many have found, the strength can vary by a factor of four or more. Storing it in the freezer seems to prevent (or at least dramatically slow down) degradation. However, even freshly received PEO may have already degraded. So, when receiving new PEO, it is useful to measure its NMEC in order to know if adjustments need to be made when brewing bubble juice.

I am developing a simple procedure that can be used to gauge the strength of one's PEO.

At some point, we will modify all the PEO-based recipes on the wiki to include a reference to the PEO's strength so that one can adjust the recipe as needed.

PROTOCOL OVERVIEW[]

This section gives an overview of the protocol.

DESCRIPTION[]

Determine the Nominal MInimal Effective Concentration (NMEC) for your PEO by adding 1 ml at a time of a PEO-containing solution to 100 ml of a water:detergent solution and measuring the bubbles-per-dip blown with a small plastic wand after each addition.

NMEC[]

The Nominal Minimum Effective Concentration (NMEC) is the PEO concentration at a stream of 5 bubbles-per-dip can easily be blown with a 5% detergent solution that contains PEO. We propose that NMEC is a useful measure that can be used to establish the potency of PEO (usually PolyOx WSR301 or J-Lube).

NMEC is not the minimum concentration at which PEO has an effect. PEO typically has an obvious impact at well below the NMEC. Around 5 bubbles-per-dip has been chosen for the NMEC as it seems a practical measure of the minimum concentration required for a friendly solution. This is not necessarily the optimal PEO level. It is a somewhat arbitrary but useful reference point.

How to use it? There are a few ways that you might use the NMEC.

  • To determine whether you need to adjust the amount of PEO you use when using other people's recipes.
  • To determine if your PEO's potency has changed over time. To do this determine your NMEC when you first receive your PEO and then every few months or so.
  • As a basis for making up your own recipe. NMEC gives you a sort of baseline idea of how much PEO is needed to start having an effect. You might use quite a bit more, or you might want to use a bit less in a multi-polymer mix.

WHAT YOU NEED[]

  • PEO (J-Lube or PolyOx WSR301)

Dawn Pro or Fairy detergent (or one of equivalent strength)

  • Small Plastic Wand
    EAS small plastic wand for web

    A small plastic wand is invaluable for troubleshooting and testing.

    (Mine is a ridged wand provided with 8 counce bottles of Super Miracle Bubbles. Inner diameter 16 mm. Outer diameter 25 mm).
  • A way to accurately measure and dispense 1 ml of fluid (a low-capacity syringe is recommended. I use a 3 ml syringe that came with some medication) what has reasonably space 1/4 ml markings.
  • Water
  • A way to accurately measure small amounts of ingredients. A scale accurate to tenths or hundredths of a gram (these can be purchased for less than $20) is recommended. See notes below for what to do if you do not have such a scale.

PROCESS OVERVIEW[]

This section provides an overview of the process. We will be adding a section with a highly detailed step-by-step procedure soon (including the specific recommended recipes for solutions A and B). There are some minor but important details left out of this overview.

Preparation[]

  • Make a dilute water and detergent only solution (with a 19:1 water:detergent ratio) that we will call Solution A.
  • Make a solution that we will call Solution B that is 0.04% PEO and has a 19:1 water:detergent ratio.

Establish baselines[]

Solution A Baseline

  1. Using a small plastic wand, record the bubbles-per-dip created by blowing a stream of air for 10 dips with Solution A
  2. Observe the stringiness of Solution A when the excess flows from the wand as you remove it from the solution.

Solution B Baseline

  1. Using a small plastic wand, record the bubbles-per-dip created by blowing a stream of air for 10 dips with Solution B
  2. Observe the stringiness of Solution B when the excess flows from the wand as you remove it from the solution.

Find the NMEC[]

  1. Measure 100 ml of solution A into a dipping container suitable for dipping the small plastic wand
  2. Record the bubbler-per-dip create by blowing a stream of air for 10 dips.
  3. Add 1 ml of Solution B and stir.
  4. Record the bubbles-per-dip created by blowing a stream of air. Perform 10 dips.
  5. Repeat steps 3 and 4 until the average is bubbles per dip is 10 or above.
  6. Look at the trials worksheet and find the trial where the average bubbles-per-dip was about 5 or 6. The amount of solution used for that trial provides the NMEC basis.
  7. Perform the simple calculations (see farther down this page) to determine the NMEC.


Report[]

Download this worksheet: File:2014 07 PEO Trial Worksheet.pdf

 

Report detailed results to the SoapBubble Wiki (see sample worksheet).

DETAILED PROCEDURE[]

Worksheet. Download the worksheet to record your results: File:2014 07 PEO Trial Worksheet.pdf

 

pdf of details needed? I can create a pdf file with the detailed directions and recipes. Let me now if this would be helpful by adding a comment.

SOLUTIONS NEEDED[]

The protocol makes use of 3 solutions:

  • 1% PEO Solution
  • Solution A: simple 19-to-1 water/detergent mix
  • Solution B (Calibration Mix): is a 0.04% PEO solution that is also contains 19 parts water to 1 part detergent.

MEASUREMENT NOTE: Make sure that your scale is accurate enough to make the 1% solution. If you have a scale that can measure hundredths of a gram, using one gram of PEO is fine. If your scale is accurate to tenths of a gram, I recommend making a quadruple batch. For a scale that measures only to the gram, multiply by 10 for PolyOx or by 4 for J-Lube.

1% PEO SOLUTION[]

If possible, mix this solution 24 hours or so before the test. Testing has shown that this solution's properties can change over the first 24 hours. Store it in the refrigerator after mixing.

While there are other valid methods of mixing PEO, please use this method in order to maximize the universality of the results. The method used to hydrate the PEO influences the final viscosity (sometimes dramatically). So, we have chosen an easy reliable method.

For conducting this test, a 1% PEO solution is required for the preparation of Solution B. The recipe is slightly different for PolyOx WSR301 and J-Lube to account for their different PEO concentrations. WSR301 is essentially 100% PEO while J-Lube is 25% PEO. In order to standardize test results as much as possible, we recommend using distilled or deionized water. Tap water is ok if you don't have distilled water on hand.

Chilled Dry Alcohol. This protocol makes use of chilled dry alcohol. Get isopropyl alcohol that is 90% or higher pure -- the higher the better. Chill your alcohol by putting it in the freezer. The colder the alcohol, the less likely it is that the small amount of water will cause clumping. Normally, a tiny amount of clumping can be tolerated -- but to maximize the meaningfulness of the results -- we want to eliminate it as much as possible.

The amounts below assume that you have a scale accurate to .01 grams. If you do not have such a scale make a larger batch. You can double, triple, quadruple, or more the ingredients to minimize the influence of equipment precision.

WSR301 Recipe Ingredients:

  • 9 grams chilled 90% (or higher) isopropyl alcohol
  • 1 gram PolyOx WSR301
  • 90 grams room temperature water (preferably distilled)

J-Lube Recipe Ingredients:

  • 9 grams isopropyl alcohol
  • 4 grams J-Lube (this contains 1 gram of PEO and 3 gram of sugar)
  • 87 grams room temperature water (preferably distilled)

MIXING PROCEDURE

Needs:

  • small cup for mixing slurry
  • 1 cup capable of holding 150 ml of liquid. A bit larger is ok. If making a large batch, make sure the container is at least 1.5 times the volume of the water used.
  • optional identical cup for testing self-siphoning
  • a stirring rod, chopstick or fork
  • a squeeze bottle (or other storage container) for the finished solution.

Procedure:

  • Make a slurry. Add the PEO (the J-Lube or the WSR301) to the chilled alcohol and stir with a stirring rod or chopstick (or fork) to distribute. There should be no clumps.
  • Start stirring your water with a stirring rod, chopstick or fork and gently pour the slurry in a stream into the stirred water. If you pour too fast, you may get some clumping. If this happens, you should start over.
  • Continue stirring for about 2 minutes.

The solution should be clump free. If it is not, make a note of it.

OPTIONAL SELF-SIPHONING TEST

One indication of PEO potency is how self-siphoning it is. Start pouring from one cup into the other. Once the pour has started, adjust the angle of the pouring cup to about 60 degrees. If the PEO is strongly self-siphoning, most of the remaining fluid will climb up the incline and down into the receiving vessel. https://www.youtube.com/watch?v=s_3DP3QYqos

Make a note of whether the solution was self-siphoning

For detergent, use Dawn Pro, Fairy or equivalent. Other versions of Dawn may be used. Preferred versions (in order of preference): Dawn PowerClean, Dawn Platinum, Dawn Pure Essentials, Dawn Ultra.

SOLUTION A (simple 5% detergent solution)[]

  • 950 grams room temperature water
  • 50 grams detergent

Combine the ingredients and stir gently till uniform.

SOLUTION B (PEO/Calibration Solution)[]

  • 455 grams room temperature water
  • 25 grams detergent
  • 20 grams 1% PEO Solution (as described above)

Combine ingredients of solution B and gently stir for a minute of so. We highly recommend mixing this up at least one hour before the test to ensure that the PEO fully integrates.

Test Procedure[]

NEEDS:

  • equipment (described below)
  • Solution A (water and detergent mix)
  • Solution B (water, detergent, PEO mix)

EQUIPMENT:

  • a dipping container capable of holding 150 - 200 ml fluid that the small wand can be dipped in.
  • a syringe capable of dispensing (accurately) 1 ml of fluid -- the protocol can be adjusted to use another amount of fluid. It is very important that you use a syringe where you can dose out 1 ml rather than 1.2 or 1.5 ml. If you don't have such a syringe, adjust the amounts of everything so based on the increments that can be accurately dispensed. If you have a syringe that can accurately dose 2 ml but not 1 ml adjust the amount of solution used

PROCEDURE[]

Bubble-blowing note: try to be consistent with your bubble blowing technique. Don't try to be super-refined to compensate for finicky solutions. Hold the wand a few inches from your mouth and blow gently to see how many bubbles-per-dip you can get with fairly casual blowing.

Make a worksheet for entering your results or use the one that we have provided (see link earlier in the article).

Establish baselines - making bubbles with both Solution A and Solution B at full concentration

  1. Using the small plastic wand, record the bubbles-per-dip created by blowing a stream of air for 10 dips with Solution A
  2. Observe the stringiness of Solution A when the excess flows from the wand as you remove it from the solution.
  3. Using a small plastic wand, record the bubbles-per-dip created by blowing a stream of air for 10 dips with Solution B
  4. Observe the stringiness of Solution B when the excess flows from the wand as you remove it from the solution.

If the PEO is very old, Solution B might work very well. If the PEO is fresh, you might occasionally get many bubbles per dip but are most likely to get a lot of failed dips.

Find the NMEC (nominal minimum effective concentration)

NOTE: If using a syringe that accurately doses 2 ml (but not 1 ml), use 200 ml of solution A in step A. If using another increment, start with an amount that is 100 times larger than the increment of solution that is added in step 4.

  1. Measure 100 ml of solution A into a dipping container suitable for dipping the small plastic wand
  2. Rinse the wand and shake it hard to remove excess water.
  3. Record the bubbles-per-dip create by blowing a stream of air for 10 dips.
  4. Add 1 ml of Solution B.
  5. Rinse the wand and shake it hard to remove excess water.
  6. Gently stir the solution with the wand to ensure that it is well mixed
  7. Record the bubbles-per-dip created for each of 10 dips.
  8. Record the 'stringiness' of the solution.
  9. Repeat steps 4 through 8 until the average is bubbles per dip is 10 or above.
  10. Look at the trials worksheet and find the trial where the average bubbles-per-dip was about 5 or 6. The amount of solution used for that trial provides the NMEC basis.

Why go to 10 bubbles-per-dip rather than stop at 5? We've found it useful to continue the series to see if the progression is expected which is helpful as we refine this method and for spotting a possible glitch in performing the procedure.

SAMPLE WORKSHEET[]

You should end up with a worksheet that looks something like this. (Your numbers will be totally different.)

BASELINES

Solution A. Bubbles-per-dip: 0,2,0,1,1,1,0,3,0,2

Solution B Bubbles-per-dip: 10,12,9,0,1,1,10,13,10,20


FINDING NMEC

Starting with 100 ml solution A. Adding solution B in 1 ml increments.

Dip # Solution Bubble-per-dip (10 dips) Stringiness
1 Solution A No Solution B 0,2,0,1,1,1,0,3,0,2  Not stringy
2

Add 1 ml solution B

1,4,0,2,2,1,1,1,1,1 Not stringy
3 Add 1 ml Solution B 2,0,4,1,2,4,3,1,4,3 ever so slighty stringy

etc.


Calculating NMEC and Adjustment Factor[]

To calculate the NMEC, perform the following calculations:

  • TOTAL SOLUTION. Add the the total amount of solution B used to the amount of solution A used.
  • SOLUTION B AMOUNT. Add up the total amount of solution B needed to achieve an average fo 5 bubbles-per-dip/
  • TOTAL PEO AMOUNT. PEO Amount is 0.04% of the amount of solution B used. To calculate it multiply 0.0004 * the amount of solution B used.
  • PEO grams/ml solution = Total PEO Amount/Total Solution. This will be a TINY number.
  • NMEC (PEO) = 1000 muliplied by the PEO Grams/ml.
  • NMEC (JLUBE)= If you are using J-Lube, multiply the NMEC you calculated above by 4 (since J-Lube is only 25% PEO) to find the J-Lube NMEC.

Calculating the Adjustment Factor. The adjustment factor is how much more of your PEO you need to use than that in a given recipe (assuming the recipe is based on full-strength PEO). To calculate it, divide your NMEC value with the NMEC value found on the PEO page (based on our review of data that people have sent us an our own trials). For example, if your NMEC for WSR301 was 0.016, divide 0.016 by 0.008 (the value on the PEO page as of this writing in June 2017). This calculation returns 2 as your adjustment factor. This means that you should use about twice as much PEO as a recipe calls for (as long as the recipe was based on full-potency PEO).

J-Lube Adjustment Factor. When calculating the adjustment factor, make sure that you use the J-Lube rather than PEO value.

Further Thoughts[]

You may notice that this method involves calculations that assume that the amount of bubble juice is not changing with each dip of the wand. While it is true that each dip removes solution, for the sake of this test, little enough juice is removed that the calculations still end up in the right ballpark even if not precisely correct.

Further refinement can be done by mixing up some simple juice using the NMEC approximation that you get and seeing if you get similar results. If not, you can refine your estimate accordingly.

There will be some variation from person to person based on their bubble-blowing skill, but even with these variations, it seems that a reasonably usable value is achieved. I have made various bubble-blowing apparatuses and tried various commercial machines and the improved precision seems to have limited payback. This test will catch the sort of large-scale changes that happen over time if you don't store your PEO well -- and should also catch the large-scale differences in potency that some people see right of the shelf.

MATH NEEDED!!!!! Edward needs to add a section on how to get the NMEC from your results.

NEEDS MENTION: Write up method for 'Basic PEO Juice' with amounts that put one at the NMEC threshold. This should be useful in gauging potency and/or preferred amount.

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