My wife is trying to make a solution of water & l-ascorbic acid (however you spell it). The solution has to have a pH of less than 3.0 or else the l-ascorbic acid apparently will not absorb and will break down. It needs to be a minimum of 15%-max 20% in the water. She's down with ferulic acid or vitamin e for stabilization. She just can't figure out how to get the l-ascorbic acid to dissolve correctly.
Currently she's been trying distilled water, but this isn't working.
This is for some sort of skin care regimen, but I don't understand her witchdoctor stuff.
Any chemists or chemistry majors who can help me out?
Arrrgh Capn, Sar. Reportin' for duty, Sar.
According to an MSDS I just checked, ascorbic acid is water soluble up to 33 grams per 100 grams of water. Making the initial solution should be a matter of dissolving 15 grams of the powder in 85 grams of water to get a 15% solution. I'm afraid it's been too many years and I can no longer calculate the pH. But you should be able to buy pH paper at a pharmacy and just measure it. If not, most good-sized cities have chemical supply houses that will sell over the counter. pH paper is inexpensive. They make different papers that measure different ranges. Make sure you tell the fella behind the counter what pH you need to measure.
Once you measure the pH, if the solution is too acidic (pH is too low) then you can bring it back up with a bit of Tums. If the pH is too high, you can add a drop or so of vinegar. If you want a bigger batch (100 gram is a pretty small volume) you can bulk up the formula by multiplying the amounts.
Neither vitamin E nor ferulic acid is water soluble. So if you combine either of them with the solution, you will only get an oil in water gloppy mix (you should pardon the technical language) like Good Seasons Salad Dressing. I'm not sure what she wants to do with those. Perhaps she wants to make a hand cream? She might be able to make an emulsion. Most hand creams are emulsions. Ferulic acid should make a reasonably stable emulsion without the need for further emulsification agents, though this is just an educated guess about not needing further emulsifiers.
If she wants to make an emulsion or hand cream type of deal, that may be possible in the kitchen. In order to get an emulsion, you need shear. Lots of shear. You should be able to use a kitchen blender to do that.
There are two types of emulsions. Oil in Water (drops of oil in water), and, Water in Oil (drops of water in oil). For a hand cream I think you can use an oil in water emulsion. I've made those in the lab, but it was about 15 years ago.
Start with the oil. Put enough in the blender so as to be maybe an inch or two above the blade. Turn on the blender with it set on low or medium. Add the acid solution slowly in small increments, almost drop-wise. The blend will get thicker and as you get more acid solution in, it will turn white. As you add the acid solution, it will get thicker and thicker. Then all at once, it will drop in viscosity. That marks the point where you now have drops of oil in water instead of drops of water in oil. The technical term for it is "inversion".
Once the emulsion inverts, adding more water will cause it to get thin. Probably not what she wants. If it were I, I think I would stop as soon as the emulsion inverts. It should be reasonably stable using those oils, but you may need a stabilizer to keep it as an emulsion for a long time. What I'm try to say here is that there is a tendency for the droplets to recombine and become just oil mixed with water, which is probably the gloppy stuff she has now.
If I have guessed wrong as to her intentions, my apologies. Feel free to drop me an email and I'll see if I can do better.
Arrgh!
