My first colloidal silver

[miros]

I made two concentrations of colloidal silver

1. First is 20 ppm (1mA ,75 min. , later I tried 5mA 15 min)
2. Second attempt was to get 100 ppm concentration but its very cloudy (made with 5 mA and 75 min.)

Is it any chance to get clear 100 ppm stuff ?

[Kephra]

The 20ppm looks great, the 100ppm needs a little work.

What exactly did you use?  Did you use any maltodextrin, corn syrup, cinnamon, sodium hydroxide, etc?

[miros]

I used few drops of 20 mg/ml NaCl solution then few drops of inverted table sugar.
I noticed that if less current you use less NaCl you need to have constant current from the begining.

How much of inverted table sugar do I need in milligrams to reduce silver ions for 20 ppm solution ?

[Kephra]

I have never weighed how much invert sugar, I just use a couple of drops.

To get higher ppm, I believe you will have to use sodium hydroxide in place of table salt for the electrolyte, and possibly a different reducing agent.  Yours is cloudy because you were making silver salts faster than the reducing agent was converting it into silver particles. 

[miros]

My CS was getting cloudy during the process and I put reducing agent at the end.
Would it be good to put reducing agent at the beginnuing ?

I would like to try use NaOH as an electrolyte but don't know how to prepare it.

[Kephra]

You need the invert sugar (reducing agent) from the beginning. 
To prepare the sodium hydroxide solution, you dissolve 4 grams of sodium hydroxide in 100ml of water.  CAUTION: sodium hydroxide is highly caustic, so wear rubber gloves and eye protection.

[miros]

Thank you for your explanation
Not all is clear for me. I will read the forum and ask questions and I hope you will not be offend Kephra

Do you mean I need reducing agent  from the beginning just for 100 ppm CS not for 20 ppm
I used inverted table sugar for 20 ppm CS at the end and you said it looks good

What is difference between adding reducing agent at start point  and at the end ?
Could reducing agent be electrolyzed ?

[Kephra]

You need the reducing agent from the beginning to make higher ppms because the silver hydroxide that the electrolysis makes is only soluble to 20ppm.  After that, it starts to precipitate as particles of silver oxide.    Once the silver precipitates as silver oxide, the invert sugar can no longer convert it to nano sized silver metal particles.  So your solution is then a mixture of metallic CS and undissolved silver oxide.

If you add the reducing agent at the beginning, the silver ions are reduced to metal as they are being made, and do not accumulate to the point where they precipitate out.  In that case, you get almost pure metallic silver and no ions.

[miros]

I made an experiment today

   I made 2 sets of 20 ppm CS

1. A few drops of NaCl (as electrolyte) + inverted table sugar (all at the begining)

2. A few drops of NaCl (as electrolyte) + inverted table sugar (at the end)

For number 1 I got cloudy CS with much stronger Tyndall effect but
for second attempt CS was much more cleaner with weaker Tyndall effect

Which one is better as colloidal ?

Sorry but:
third and fourth picture should be as first and second

[Kephra]

The best is the second where you added the corn syrup at the end.  This is because some of the sugar is electrolyzed to gluconic acid and doesn't have the same reducing power as glucose and fructose do.

A strong tyndall effect (turbidity) is undesirable as it indicates that the solution contains more large particles.

However, this only works for lower ppm solutions.

For higher, I recommend cinnamon instead of a sugar based reducing agent.  Also, sodium hydroxide works better because silver hydroxide is more soluble than silver chloride, and it activates the reducing agents better.
 

[miros]

I have a chance to buy at lower price this magnetic stirrer with hotplate:

http://www.ika.com/owa/ika/catalog.product_detail?iProduct=3810000&iCS=1&iProductgroup=188&iSubgroup=1

But I wonder if magnetic field is good when you make colloid.
I don't know what happens to ions when they under that field.

With regards

[Kephra]

The magnetic field does nothing to the colloid.

Here is the one I have, when I bought it a couple years ago it was about $120.
http://www.amazon.com/Magnetic-Stirrer-with-Hot-Plate/dp/B0026KHYFQ

[miros]

Some time ago I bought this colloidal silver but it is nothing more than ionic one

And on the bottle there is written: keep away from magnetic fields
I wondered what magnetic field has to do with that liquid, so why my question

If you make CS you have ions first which turn later into metalic form

[Kephra]

Silver is unaffected by magnetic fields.

If you make colloidal silver by electrochemical or chemical processes, it always starts out as ionic. 

[miros]

You mean both silver particles and silver ions are unaffected by magnetic field

I thought silver ions could be affected because the are positivly charged

Regards