Well I don't know about 10-15 years, but 3.5 years in my freezer and the caps are fine, as is the nic. Wax seal is perhaps overkill, but maybe not. VG-nic stores better in the freezer than PG-nic, however.
The real issue as I see it is if it is sealed in glass, the primary O2 reactions are from naturally solubilized O2 in PG or VG, not O2 getting in from the air, or even opening it every few months. Low mobility of the liquid, thick gel-like cold VG, means lower mobility of the reactants, and cold lowers the kinetics even more. As I said, 3.5 years on much of my VG-nic and no changes at all. Amber glass, poly caps, freezer, that's it. At room temperature, yellowing over weeks and months is likely due to O2 already present.
No, I don't have citations for this. I have bottles designed for long term storage of reactive chemicals. And a bit of experience in the lab. Personally I would like to see 100 mL bottles or smaller with rubber septa for syringe dispensing. I use eurodropper inserts for this, they work well, anti-spill, and act as gaskets for the cap. MFS sells bottles with rubber septa, or used to. The septa I used to use were like crimp on bottle caps or old, and once you removed it, that's it, can't put it back on, like an old soda bottle.
Of course, one could if one was worried, put the bottles in a large vacuum sealed container with O2 absorbing packets inside. this was discussed a few years ago, and it was decided that was overkill. I have not found a need myself, but then I don't vape PG-nic...again, however, the aging in the freezer I have seen from SOME Pg-nics was almost certainly from O2 already in the PG when the liquid was made.
So, how do we deal with solubilized O2? Vacuum will not remove it. I don't think it can be removed. I don't know of molecular sieves that will do this. It's there. Not much, but its there, and it takes very little nic-oxide to yellow a nic liquid. All I know to do is increase viscosity and lower kinetics with cold. Get PG cold enough to set up thick like VG, and it seems to me the PG-nic issue is pretty much solved. Normal freezers seem cold enough for VG-nic.
There are no studies I know of that verify that PG- or VG-nic can be stored perfectly for 10-15 years. The stuff has not been around long enough. None the less, I expect mine to last that long, no problem, based on my experience in chemistry.
The real issue as I see it is if it is sealed in glass, the primary O2 reactions are from naturally solubilized O2 in PG or VG, not O2 getting in from the air, or even opening it every few months. Low mobility of the liquid, thick gel-like cold VG, means lower mobility of the reactants, and cold lowers the kinetics even more. As I said, 3.5 years on much of my VG-nic and no changes at all. Amber glass, poly caps, freezer, that's it. At room temperature, yellowing over weeks and months is likely due to O2 already present.
No, I don't have citations for this. I have bottles designed for long term storage of reactive chemicals. And a bit of experience in the lab. Personally I would like to see 100 mL bottles or smaller with rubber septa for syringe dispensing. I use eurodropper inserts for this, they work well, anti-spill, and act as gaskets for the cap. MFS sells bottles with rubber septa, or used to. The septa I used to use were like crimp on bottle caps or old, and once you removed it, that's it, can't put it back on, like an old soda bottle.
Of course, one could if one was worried, put the bottles in a large vacuum sealed container with O2 absorbing packets inside. this was discussed a few years ago, and it was decided that was overkill. I have not found a need myself, but then I don't vape PG-nic...again, however, the aging in the freezer I have seen from SOME Pg-nics was almost certainly from O2 already in the PG when the liquid was made.
So, how do we deal with solubilized O2? Vacuum will not remove it. I don't think it can be removed. I don't know of molecular sieves that will do this. It's there. Not much, but its there, and it takes very little nic-oxide to yellow a nic liquid. All I know to do is increase viscosity and lower kinetics with cold. Get PG cold enough to set up thick like VG, and it seems to me the PG-nic issue is pretty much solved. Normal freezers seem cold enough for VG-nic.
There are no studies I know of that verify that PG- or VG-nic can be stored perfectly for 10-15 years. The stuff has not been around long enough. None the less, I expect mine to last that long, no problem, based on my experience in chemistry.
