I see you are a fan boy Giraut, so here you are:
The Nickel Ionization Energy is the energy required to remove from atom one mole of electrons with subsequent production of positively charged ion of Nickel. Ni -> Ni+ + e- This process can be repeated many times, but the energy cost is increased dramatically. Enthalpy of atomization for nickel: 431kj
The general equation for the Nickel is: NiN+ -> Ni(N+1)+ + e-
Ni -> Ni1+ = 736.7 kJ/mol = 176.24 Kcal/mol
Ni1+ -> Ni2+ = 1753 kJ/mol = 419.38 Kcal/mol
Ni2+ -> Ni3+ = 3393 kJ/mol = 811.72 Kcal/mol
Ni3+ -> Ni4+ = 5300 kJ/mol = 1267.94 Kcal/mol
Ni4+ -> Ni5+ = 7280 kJ/mol = 1741.63 Kcal/mol
Ni5+ -> Ni6+ = 10400 kJ/mol = 2488.04 Kcal/mol
Ni6+ -> Ni7+ = 12800 kJ/mol = 3062.20 Kcal/mol
Ni7+ -> Ni8+ = 15600 kJ/mol = 3732.06 Kcal/mol
Ni8+ -> Ni9+ = 18600 kJ/mol = 4449.76 Kcal/mol
Ni9+ -> Ni10+ = 21660 kJ/mol = 5181.82 Kcal/mol
Okay, that doesn't say anything about:
- Whether nickel ionization occurs in significant quantity with the base metal in solid form,
- Whether the ions (or other nickel compounds - oxides or others) actually get dissolved in PG or VG, particularly considering that it doesn't necessarily sit in the atomizer for a very long time, and there isn't that much of it actually in contact with the base metal,
- The rate at which this may occur, and the influence of temperature - especially around 300C, which is what interests vapers,
- Most importantly, assuming liquid VG and/or PG carries harmful amounts of nickel, whether the nickel gets vaporized alongside the liquids and gets in the vapor, or whether it stays behind in the atomizer,
- And if traces of nickel are found in the vapor, whether the concentration carries significant toxicity, especially compared to what you get out of regular cigarettes.
Now, objectively, my grounding in chemistry is much too flimsy to answer any of these questions - and I'm not an toxicologist either. But I suspect testing would have to occur to answer them.
My original reasons for stating that nickel doesn't dissolve willy-nilly into the juice (and into the vapor, which again, is another thing altogether) are:
- If significant amounts of nickel got into the juice, you'd see the resistance of the coil slowly creep up as the wire sheds material and becomes thinner. However, I don't see this at all: my coil consistently reads 0.21 ohms +- 0.01 at room temperature, and I've been using the same coil for weeks.
- Nickel wire has been used for years as non-resistance wire in cartos and atomizer heads, and to my knowledge there hasn't been a rash of nickel-related reactions in vapers.
- After a short while, nickel gets covered in oxide that's non-porous, and that layer of oxide gets covered a little later with a layer of the black gunk that we all know and hate (but I don't know if the gunk itself is non-porous). That isolates the juice from the base metal, and to a certain extent, from the layer of oxide.
Having said all that, your post at least introduces doubts in my mind.
As it turns out, I may have a way to get partial answers: my company deals with chrome and nickel plating, and they have a testing lab to comply with REACH requirements. Surely they have means to test for the presence of nickel in solutions. If they do, I'll leave them the wick in my atomizer for them to test: it's been in there for over a week and it's high time I changed it. If it contains nickel, it should be as satutated with the stuff as can be. And if it does come out positive, then I'll get them to test condensed vapor.
If my company can't or won't test my samples, I know a jeweler who has a solution to assay precious metal alloys and test for the presence of nickel.
Of course, if any of these tests come out negative, it won't say anything about the presence of nickel in the juice - just that this particular test doesn't detect it. But if they come out positive, then that'd be a worry.
I'll let you know what my company's labrat says tomorrow.