Color or Tyndall Effect- what should be a standard for particle size ??

[orionis83]

Hi

I am having great time in making my colloidal silver solutions. Yesterday I tried Cinnamon tincture and reduction was amazing. It was as fast as Borohydride and silver came out perfectly crystal clear. It was little darker compared to malto reduced silver. I have read some where that colour of silver reflects the particle size. So in this case cinnamon gave darker colour.

I tried a laser beam to check tyndall and to my surprise malto reduced silver has very strong but uniform tyndall effect. On the other hand cinnamon reduced silver gave very weak tyndall , barely visible in day light. So my question is what should be considered a good indicator for particle size between color and tyndall effect.

Thanks.

[cfnisbet]

The slightly darker colour of the cinnamon-capped Colloidal Silver is due to the capping effect, not the actual particle size of the silver nanoparticle.

Ignore any Tyndall effect. The only thing that matters is clarity. The finished product should be ideally, crystal clear. Some level of faint opalescence, although undesirable, is acceptable as long as you can see clearly through the liquid.

At 20 ppm, (higher ppm is always deeper colour) sugar-reduced should be the colour of Johnson's Baby Shampoo, cinnamon-capped should be the colour and clarity of whisky. Maltodextrin is normally yellow, but may be a bit deeper colour, particularly if higher ppm.

[orionis83]

Thanks. My cinnamon reduced silver is crystal clear.

I have one more question is there way to determine the whole silver ions have reduced. Right now my only way to test is taste. Right after adding cinnamon tincture drops ions will turn dark yellow but they still have little metallic bitter taste. After 2-3 hours metallic taste is gone. So I guess reduction is complete. Do we have some other test ??

 

[Neofizz]

Adding extra reducer will ensure complete reduction. We (I) always add excess reducer to be sure that all silver ions are reduced. Kephra's formulas are precise but the reducer is in excess, more than is needed to ensure complete reduction. It does not hurt to add extra reducer. If you are not sure if it is completely reduced, add a little bit more reducer and see if the colour changes any farther.

Even when I add extra reducer (maltodextrin or glucose) there is still not enough to taste any sweetness.

[cfnisbet]

... I have one more question is there way to determine the whole silver ions have reduced. Right now my only way to test is taste. Right after adding cinnamon tincture drops ions will turn dark yellow but they still have little metallic bitter taste. After 2-3 hours metallic taste is gone. So I guess reduction is complete. Do we have some other test ??

While I agree with Neofizz' comments, my personal attitude is that slow reduction gives better results, so I would personally prefer to use your "method", whereby the product is allowed to finish reduction by itself. No other test is necessary. The human taste test would be perfectly adequate, and if you do this often, with the same results each time, you can then forget about it, in the knowledge that it will happen by itself each time you make a batch.