----- Original Message ----- From: "Marshall Dudley" <[email protected]> To: <[email protected]> Sent: Tuesday, 28 November 2000 05:47 Subject: Re: CS>again
> Ivan Anderson wrote: > > > > But we are talking about CS, which are charged clumps. If they don't > > have a > > > charge, they drop out of the colloid, and will not be drunk. > > > > Not necessarily, a particle does not need to be charged to remain > > suspended, just of colloidal dimension. > > > > Although browning movement will keep particles suspended against the pull of > gravity for a while, without the charge, I believe all particles will > precipitate. Even the cream in homonogized milk has a charge associated > with it if I remember right. What would counter the pull of gravity if they > did not have charge? Random walk cannot do it long term, as gravity will > polarize the walk toward the bottom. Gravity is not interested in charge, only mass. Even the most highly charged colloid if left undisturbed for some measure of time, will be found to be more concentrated at the bottom than at the top of a container. The degree of dispersion, hydration, size, charge, Brownian motion, etc all have an influence on the stability of a colloid, and the time taken for a colloid to settle out. Most of your statements below leave me somewhat bewildered...I guess I will have to do some experiments myself. Shall be in touch! Ivan. > The repulsion between particles of CS is decreased by acid, that is why > particles tend to aggregate in an acid. The atoms being positively charged > would tend to repel each other, but stick together anyway, not sure why, > sharing of electrons, or van der walls force perhaps. At any rate, > reduction of the effective charge reduces the repulsion, thus causing the > opposite effect, the atoms will stick together better, not fall apart. This > is confirmed by adding acid to CS and seeing that the particles aggregate > and not dissipate. > > > > > > This comes back to my original experiment, where I cannot get the CS > > to lose > > > its tyndall when added to HCL or nirtic acid. I do not see any action > > taking > > > place. Does this not imply that the particles are NOT being broken > > down? > > > > Yes, that would imply that the particles are not being broken apart, but > > it also implies quite large particle to begin with. As silver readilly > > reacts with dilute nitric acid I cannot understand why this should be so > > in this instance, with HCl perhaps the silver chloride is of the same > > particle size. > > > > Galvanic response is the most likely reason I believe. Silver metal has > sufficient impurities to set up a current that corrodes the silver. Pure CS > has no such impurities in most of the particles. I do notice a sudden but > slight drop in the tyndall immediately after adding acid, then over time the > tyndall increases, then drops to nothing and you find silver precipitated on > the bottom. This is my take on it. > > When you first add the acid any particles with impurities, such as copper, > in them immediate react due to the galvanic current, and thus the tyndall > goes down. Then the acid causes the remaining pure particles to aggregate, > which causes the tyndall to go up, and that is followed by the particles > precipitation out, followed by the tyndall going down again. > > It has been years since I tried this, and plan on repeating it again to > confirm my memories. > > Marshall --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.215 / Virus Database: 101 - Release Date: 16/11/2000 -- 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] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
