Hi Steven and all, On of the many projects which pops up as a reminder on my computer---only to be delayed while I run off to fix some ancient beer cooler---is to contact plastic resins chemists. Among other qualities, he surface charge characteristics of the various plastics which are used to make bottles are critical to their use for CS storage.
I have identified four important characteristics of the resins used to make bottles which are important to CS storage therein. There may be other parameters too, but these seem likely to be the most important. 1. Does the plastic release anything into the water? For example, it is well known that PVC---certainly the type used in piping---does this. Primary cross-linked Polyethylene, commonly called PEX in the industry ,is said to put absolutely nothing in the water. But who says this? The folks who sell the tubing. 2. Are the substances released toxic per se? Probably, for some materials. You can smell it. PVC is made using Vinyl Chloride. Vinyl Chloride has been identified as associated with a primary liver cancer in plastics industry workers. Forgive my lack of citations, this is from years-old memory. A friend says she can taste the difference between my still water---0.2PPM--- stored in glass and that stored in HDPE. 3. Will the substances released, aside from their primary character, react with silver? If so, it will certainly reduce the available silver, and may make some really strange stuff. I don't know. 4. After the preceding factors are eliminated from our ideal CS storage material, there remains very important issue: What is the surface charge of the material? Positive should repel the positively charged CS. Negative should make it stick to the surface. When it sticks to the surface, it will very likely loose it's charge, which will make the repulsion of other particles less, and decrease the probability of their being repelled from the already attached pieces. Particle size is probably important, as bigger pieces will still have only a single plus charge, but the attractive forces may be greater. Anyone know about that one? If there is anyone on the list who has some expertise in these matters, I would greatly appreciate their input. If others recognize the importance of these issues, and are willing to do some research sooner than I, that will benefit us all greatly. While checking this mail for errors, another possibility occurred to me. What is the effect of the plastic on ambient light falling on the bottle? Could passage through the resin, or filtering of wavelengths thereby cause a frequency to hit the CS which could affect it's charge or other qualities? Later, James Osbourne Holmes [email protected] -----Original Message----- From: Steve King [SMTP:[email protected]] Sent: Saturday, October 02, 1999 4:40 AM To: [email protected] Subject: Re: CS>rose color cs At 02:19 PM 10/1/99 -0000, you wrote: >I have had the same problem with the cs changing to a pinkish color in a >week or two. This only started happening when I started using a plastic >storage container. When I use glass this doesn't happen. Anyone else have >this experience?? Yes , definitely. When my CS isn't stable, plastic will make it turn rose coloured within an hour or two. But if its really good CS, it seems to last in plastic a long time - of course the quality of plastic seems to make a difference. Something to do with looooooong chain polymers are something : ) cheers, Steve King -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] List maintainer: Mike Devour <[email protected]>
