Colloidal silver

[Milhaus]

Hi,
i am trying to create colloidal silver  according Hans Laroo papers. I am using constant current source 500uA and LED light 420nm 5W to convert ionic silver to colloidal silver.
But i have trouble with silver film and small clumps around electrodes - mostly around cathode - see attached picture:

[Milhaus]

Because i have not received any answer from Hans Laroo ( contacted by email and web form ) i have just started new batch with electrolyte ( sodium carbonate ) 120mg/L. This increased conductivity from 1ppm to 170ppm and changed pH.

BTW it is interesting that Hans Laroo make 10ppm colloidal silver 48h at 0.5mA 2L batch. This does not correspond with information provided here. I have just computed it and it should be over 1000ppm

[Milhaus]

Ok 20ppm batch sucessfully completed. But 5W 420nm was not enough to reduce silver ions at room temperature. So i have reduced it by heating to 60-70C and illumination with 420nm LED light.

[cfnisbet]

Please read the articles. I would suggest that you add a drop of Karo or Golden Syrup to ensure full reduction.

[SaltyCornflakes]

At 0.5mA doing 2 litres 10 PPM, you must run the electrolysis for 10 hours. Both you and Mr. Laroo were incorrect.

Also be aware that at these super low currents, you are not getting much voltage either. And you need a minimum voltage for good electrolysis with Colloidal Silver. I think it was around 5-10V. I would bet that you are not hitting that. Try doing this with at least 2-5mA. You can safely go up to 20PPM at that current, since even cold distilled water can handle 20PPM dissolved.

Your picture shows very little color, I would pin that at 5-10PPM. I can't advise you on the LED method. Heat reduction is also not perfect. But if you're willing to try other reduction methods, do yourself a favor and use glucose or maltodextrin.

[Milhaus]

Thanks my fault - it should be 48ppm instead 1000ppm

I will try to heat it and add maltodextrin if it does change the color even more...

I have tried 2 batches
1. 0,6mA - around 4,7-5,5V
2. 1,64mA - around 12 - 13V

Electrode distance  21cm

Both with identical results - clarity/final PPM/colour after reduction. I dont think there is any issue with such low voltage.

Bright color does not mean always lower concentration. It could be due smaller particle size at the same ppm.

[Milhaus]

I have tried to add maltodextrin to ionic silver at room temperature ~22C in the dark and it was reduced ( changed color to yellow ) in 24hours. So it is possible to skip heating step  ?