Hi all
I'm trying to make a 2 mM poly(acrylic acid) (MW = 8000) solution, and I can't figure out which molar mass to use. Using 8000 g/mole as the molar mass produces an absurdly low number, while using the monomer molar mass doesn't seem to be helpful either.
This is in the context of making capped oxidation-resistant NPs.
Can anyone help?
EDIT - I kinda chose a weird example with the MW 8000; when the MW of the polymer becomes, say, 54,000 or 100,000, then using that to measure molarity is absolutely not an option.
2 millimolar is 16 g/L using the 8000 MW - that seems reasonable.
2 millimolar in monomer (MW = 72) is only 0.14 g/L which is pretty dilute!
but it depends on what you are doing as to which is the appropriate measure.
Dear all, I think better to use the equivalent of carboxylic acid groups instead of molarity. This is because capping efficiency and antioxidation protection is function of pH, i.e., the dissociation of acid groups. The following document is good in that PAAc is used for similar purpose as capping agent to protect against Cu oxidation in water. My Regards
https://doi.org/10.1021/acsomega.9b03995
thanks, will have a read, but it would be nice if there was a consistent standard for these. ah well.
No thanks, the only standard is the experience you will get from other work groups. These are quiet new area of investigation. One thing I forgot to tell in my in my first contribution is that becarefull about the MW range to use, don't go to higher ones, otherwise the stability of the dispersion will be lost as high MW polymer may bridges nanoparticles to induce agglomeration/floculation. My Regards
Hi;
Please see the links below:
https://www.researchgate.net/post/How-to-calculate-the-concentration-of-PVPMW-40000-in-a-solution
https://www.researchgate.net/post/How_can_I_have_a_PVP_concentration_of_036M
https://www.researchgate.net/post/Can_someone_advise_on_preparation_of_PVP_Polyvinylpyrrolidone_aqueous_solution_PVP-40
With my best regards
Dear Abhinandan Banerjee;
Polymers have a wide molecular weights distribution, so it is best to use weight % or w/v % as units for calculating polymer concentration in a solution.
With my best regards
That doesn't help me, since I am following a procedure that calls for a 2 mM PAA solution. In general, I *DO* use wt% as a metric when I deal with polymers, but I don't have that option here since I am following an established protocol, and the amount of polymer actually has an effect on the morphology and size of the NPs under consideration.
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