colloidal iron, Eric???

[wyndham]

Well I have come upon an interesting experiment that I thought I would share and see if it sparks some interest.
Taking a 29% solution of iron chloride and using 4ml add to 250 ml of boiling water makes a solution of colloidal iron.
If one passes a magnetic field by a test tube with this solution the color will change in direct relation to the magnetic field. The solution is paramagnetic instead of ferro magnetic, according to the information. The color will change from rust brown to purple.
I don't know the change time or the delay to the or state. I may have a chance to do this later. What interest me is a visual response to a field an maybe give an insight to the nature of iron.
One might also wonder if a similar effect might be seen in colloidal gold or silver. I doubt this is a silver bullet but what if the solution reacted differently to different metal induced signals.
This might be old hat to others but new to me.
Wyndham

 

[Prospector Al]

Hi Wyndham,

I found your post very interesting. I came across Ferric Chloride a few years ago while staining slides of tissue,
but I had no idea it could be used to make colloidal iron that responds to a magnetic field. Is the color change
permanent or does the color revert back to the original, when the field is removed.

I envision an aquarium filled with this solution. The field below the coil would show up in three dimensions.

Is the color change abrupt or proportional the the field strength?

Al

 

[wyndham]

Al, from the little I found out, I think the color will change back when the field moves away. The speed of the change will be the issue. I thought a test might be to have a glass with the solution and a light emitting diode with a photo receptor on either side of the glass tied to a meter to show the voltage from the LED thru the no field solution then induce a current at know levels, turn it off and see what the change is and if it goes back to the other level. It might take a penlight laser to get thru the solution.
If this has any benefits it will be to test different induced fields.
I have long thought for me at least, that I need to see a measured response either on a meter of visually from a target. Eric posted a test of a one loop coil in a previous post to show the Mv response from the GS5.
I have wondered if something like this replaced a ferrite core, how the signal would behave . Does being in solution act faster or slower than a solid?
Later Wyndham

 

[Prospector Al]

Hi Wyndham,

I think the particles in suspension would react slower than in a solid. In a solid piece of magnetite, there is coupling
between the domains. When the magnetic particles are in a matrix of inert material, the specimen shows" magnetic
after-effect", or "magnetic viscosity", which means that there is a delay between the imposed field and the flux.
(This is what happens in "hot rocks".)

I speculate therefore that colloidal iron would respond slowly to an external field. If the concentration is high enough,
it might be possible to get a measurable magnetic signal, else, some optica method to measure the change in
color or turbidity would have to be used.

I hope you keep up your experiments...

Al

 

[wyndham]

Al, if the induced field causes a color change that would seem to imply a change to a charged field. Since we know that the magnetic field induces an eddy current, would there be a charge in the solution?
I might be going in the wrong direction but it makes me think of a Leyden jar or capacitor if the charge is contained.
If it is something different it would have to be a change in the oxygen bonding or releasing from the iron. Something like anodizing aluminium. if it were this it would seem to be permanent
I plan to try this experiment sometime in the near future. Radio shack should still carry the iron solution.
I also saw a page on making colloidal silver for health purposes. it was a jar with distilled water and two leads of silver wire and a battery group make up of 3 9v batteries hooked up to attain 27 v. over several hrs a cloudyness came from the silver leaching into the water.
Thanks for your interest Wyndham

 

[Eric Foster]

Interesting thread. I remember once reading about a liquid that is commercially available to "see" magnetic fields. As far as I recall it was a iron mineral with a "platey" structure, maybe specular hematite. With no field, the microscopic plates are aligned at random, and light can pass through. An applied field lines them up, so that all the plates face the same way, and the liquid becomes opaque, even mirror like, so that it reflects light. Worth doing a Google search.

Eric.