Yes, We went through this before, but I still have trouble resolving the issues in my mind.
The variables as I see them : voltage current current density of electrode particle density Any one variable is dependent on all the others. Rise in voltage, leads to rise in current, leads to a rise in current density, leads to a rise in particle density which travels towards the cathode at a higher speed. Limit current = limit in current density = lower voltage = limit particle density which travels at lower speed. Control voltage = control current (by removing wetted depth of electrode) = higher current density = higher particle density travelling at higher speed. The velocity of an ion in an electric field is the product of the field strength E(Vcm^-1) and its electrophoretic mobility U(cm^2 V^-1 s^-1). The ion is instantly accelerated to the velocity where the resistive forces (viscosity of medium etc.) equal the attractive forces, where upon the ion travels at a constant rate. v = EU(cm s^-1) For silver ions (effective radius of 0.15nm) U = 6.4 x 10^-6. Larger ions = slower speeds. Higher charge = higher speeds. So at a field strength of 1Vcm^-1 the velocity = 6.4 x 10^-6 cm s^-1 which is very slow unless you are an ion. Obviously it is not the voltage that is the main diffusion factor in CS production but thermal or mechanically induced currents. Ivan. ----- Original Message ----- From: "Marshall Dudley" <[email protected]> To: <[email protected]> Sent: Wednesday, 13 December 2000 05:59 Subject: Re: CS>Progress report w/ingot > We went through all this about a month ago. What is important is the density > of particles near the electrode times the length of time they are there. When > this factor goes up, the size goes up. Increasing voltage causes the > particles to move away from the electrode through elecrtophrosis faster > reducing the density. Increasing current density causes more particles to be > generated per unit of time, increasing the density. > > So we have particle density is proportional to current/voltage. > > Aggregation will be proportional to this and the length of time they are in a > high density area, ie. time*current/voltage. For all practical purposes the > voltage and current elements cancel out, leaving time, and time near the > electrode is inversely proportional to voltage, with current having minimal > effect. Thus density*time will be proportional to current/voltage^2, and > since current is proportional to voltage, we get that the density*time, or > aggregation constant, is proportional to 1/voltage. With all else equal, > particle size drops with increasing voltage. I have verified this many times > with HVAC process. I am assuming the same rules apply in the LVDC process, > but have not experimentally verified it. > > Marshall --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.219 / Virus Database: 103 - Release Date: 06/12/2000 -- 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]>
