Effect of time on solutions of Guar, PEO, and PAM
I made solutions of Guar, PEO, and PAM in distilled water and then recorded the apparent viscosity over time for 40 days, to get an idea of how quickly the solutions degrade. For each polymer I made one solution with 0.02% Propyl Paraben and one without. Propyl paraben is used as a food preservative and considered effective against bacteria, yeasts, and fungi, over the pH range of these solutions. I speculated that it could prolong the effective life of the polymer mixes.
The Guar was at 6 g/L, the PEO (WSR-301) at 4 g/L, and the PAM at 1 g/L. The Guar and PEO were slurried using 10mL of denatured alcohol per gram of polymer, and all the solutions were mixed using a relatively low shear rate paint mixer. Apparent viscosity was measured as t…
Effect of time on PAM solution
Elsewhere on this site Edward has wondered how much PAM solutions age with time so I’ve made a first attempt at measuring it. I prepared a 500 ml sample of PAM at .5 g/L with 0.01% propyl paraben (preservative) and stored it, covered, at room temperature. I then measured its apparent viscosity with a Ford #2 viscosity cup at intervals over a period of 70+ days. I did 4 repeats each time.
It takes several hours for the PAM to dissolve fully. The first measurement was 1 hour after the PAM was mixed into the water. There does appear to be some degradation after about a week.
You cannot dip the cup into PAM solution or pour PAM into the cup because it is self siphoning, so I filled the cup using a 60ml syringe. There is a possibility that there …
PAM - a new polymer for bubble juice
I've recently started playing with PAM as a bubble polymer. It looks promising but needs more investigation.
The PAM (Polyacrylamide) family is an important group of industrial polymers with an international trade value of several billion dollars annually. They come in 4 main varieties: Nonionic, Cationic, Anionic, and Cross-linked. I'm ignoring the Nonionic and Cationic varieties for now because I've yet to find a vendor with a minimum order less than 1 ton! The anionic variety I'm familiar with because the use of this in water treatment was the subject of my Ph.D. thesis, but it is not readily available for domestic use. This leaves the cross linked variety which is both readily available and cheap.
Cross linked PAM can absorb large volume…
Denatured Alcohol and Methylated Spirit are not interchangeable
Methylated Spirit ('Meths') and Denatured Alcohol are generally considered to be alternative names used in different countries for the same thing ( https://en.wikipedia.org/wiki/Denatured_alcohol ). However there may be differences that affect their use for our purposes. In the USA I use Denatured Alcohol exclusively for slurrying Guar and PEO. When visiting England I tried using Meths, which worked just fine for Guar but not for PEO. When I tried to slurry PEO (WSR 301) with Meths I got a thick goo so I think it's partly soluble.
Change of pH with time for Dawn Pro Mixes
When using the same bubble mix over a number of days I have often noticed a change in the pH from one day to the next, and I've seen similar comments elsewhere on the wiki, so I thought it would be worth studying in more detail. I made fresh mixes of 4 different types of mix and then recorded the pH over 10 days. pH v. time is shown on the graphs.
2 100ml samples of each mix were prepared in 5.5 oz plastic portion pots and pH was recorded while stirring as the mix was prepared, after 12 hours, and then daily up to 10 days. The graphs show the pH for each of the 2 samples of each mix.
I looked at 4 different types of mix:
1) No pH adjustment.
I thought that pH changes were probably due to carbon dioxide (CO2) dissolving in the mix, so one pair…