Hi everyone
Ian, I agree with your reasoning that the use of sulphur would minimise
any chance of galvanic reaction.
The 10Mohm is not really very surprising, I have measured resistance in
some of my cells around the 10Mohm as well.
The thing is that the resistance is not very straightforward in the type
of material we want to make; we are aiming for a material that somehow
"pumps" electrons through itself, from one electrode to the other.
That would seem to imply a high resistance in one direction, and
a low resistance in the other direction, which gives rise to a bias in
charge accumulation.
And that appears to mean that we should be able to measure a significantly
lower resistance in that opposite direction....
But I haven't been able to measure any clear differences in resistance when I
reverse my multimeter probes for example, so I am not sure what is going on.
It may be that this bias is very localised and temporary withing the material
matrix, and therefore not "visible" to the meter probes that "only" measure
the electrode potentials and the relative current flow obstruction between the
two, which is of course different on that macroscale than it may be on the
microscale of the material martix.
As for my recent attempts;
I have made a couple of cells with various ingredients, which have been exposed to
a low voltage DC (9V) during cooling and solidification.
The substance mix I used had a homemade sodium silicate base, which was made
by boiling fine white quartz sand with water at a heat between 120 and 180 degrees C,
then adding NaOH, and allowing those compounds to react with eachother.
If you have used the exact correct amounts the mix should form sodium silicate
with water, and if you used too little NaOH it will form sodium silicate with silicic acid
which when it cools turns into sodium silicate with water and sand.
Well, I used that sodium silicate, and added some more sand to get a mix
of 60 to 65% sodium silicate and 35 to 40% sand. Added a little bit of water
to ease stirring of the mix while heating it to around 100 degrees.
I added two different combinations of ingredients:
1) a mix of titanium dioxide, ferrous oxide, cobalt oxide, pure aluminium powder,
pure copper powder and kaolin in proportions 2:2:2:1:1:2
2) a mix of chromium oxide, manganese oxide, and the above, in proportions
3:3:2:2:2:1:1:2
I made two cells of each, one cell connected to a 9V battery to attempt to
achieve some polarisation, and one not connected at all to see what it does
naturally.
The ratios of metal compounds vs silicates was about 1:15 in all cells.
Results: nada.
One of the cells with the #1 mix additive shows a voltage of 1,5V, but
at an amperage of only 0,01 mA and that's not even stable (drops to zero
now and then, then comes back to 0,01mA, sometimes briefly 0,02mA).
The other #1 cell, the one which had been connected to the 9V feed, showed
a voltage of 1,8V at first measurement, but this dropped to near zero quickly.
It has not risen above 0,1V after that. Zero amperage readings on that one.
The other two cells are not entirely dry yet, but one of them seems to have
reacted slightly differently and the resulting material is probably too porous
to be of much use. Too porous and it retains relatively much water, plus
there's lots of dielectric air in there which doesn't really help...
The other one looks better, but still needs to settle some more.
So far not much luck in this approach, but I still need to try high voltages
for polarisation purposes. Am still looking for a good adjustable hV power
source, and in the mean time I'm using batteries and planning to use
a simple hV pulse generator.
The use of the named metal oxides does have one cool effect:
the cell materials now look really funky
The #1 mix looks very dark grey with a blue hue and a metallic luster.
The #2 mix looks dark to "army" greenish light grey.
I imagine if I add a lot more manganese it may turn bright purple
But I wasn't really going for cool coloured ceramics, although it is a nice
bonus
Regards,
Koen
