Hi,
I am investigating the solubility of PVDF in a solvent. I have reached at point at after 18-24 hours the PVDF is still not fully dissolved in the solvent.
Unable to change the solvent, I'm wondering the effect sonication may have on the speeding up the dissolution process. While this will increase the dissolution rate, i'm wondering the effecting it may have on the dissolved PVDF. will it effect the characteristics?
Also would the sonification just reduce agglomeration? And instead would it just achieve increased dispersion in the mixture instead of preferred full molecular dissolution?
Thanks
Hi,
Sonication will accelerate the dissolution of your polymer. But it will also increase the temperature of the samples. This might be a problem in the case of your polymer degrades or the solvent tends to evaporate. In the case of affecting polymer structure, if your solvent does not interact chemically with the solvent, I believe you won't have any problem.
If the solubility of your polymer is low, then particles will be formed, and sonication tends to deagglomerate them, so you will be obtaining a good dispersio of particles by sonicating. Although, if the solubility is a bit higher, then molecular disolution will be preferred in your system.
Sonication will not help in your situation, because the were no dissolution improvement after 12 -24 hours. If the analysis shows that the expected content is >90%, you may have insoluble impurities. In that case, filter or centrifuge the suspension. Also, sonication can lead to sub-micron particles that may pass through the filter and give false solubility data.
Definitely, the final characteristics of the solution can be affected. In the end, in theory, the solubility should be the same, but with the use of sonication the dissolution rate could be increased.
However, I am concerned about the integrity of the polymer .... a good option would be to add small amounts of polymer and allow it to solvate / hydrate, and repeat the procedure until saturation is reached. After obtaining that solution, you should compare it with the solution in which sonication was used. (Quite possibly the physicochemical characteristics change). But if they do not change, you will have obtained a more adequate methodology to prepare the solution.
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