From many related scientific papers, it is stated that the Water (harsh non-solvent) is added slowly to the transparent PVDF/DMF homogeneous solution (which is constantly stirred and kept at fixed temperature by means of an oil bath) until the solution turns into cloudy.
But, when I add a drop of water the polymer precipitates surrounding the droplet and takes 5/10 mins to dissolve again.
Moreover, after a certain amount of water, the agglomerate formed by the precipitated polymer all around the drop of water do not dissolve anymore but the rest of the solution looks still transparent.
Is the amount of water added until then the point that has to be considered the Cloud Point?
Thank you for helping
Hi, this is due to hydrophobic nature of pvdf, it will readily precipitate once you add water. May be you can try more dilute solution (8, 10, 12) rather than concentrated one.
The point at which your precipitate doesn't dissolve is your cloud point.
Hope this helps you.
Regards
DMF and water react chemically in an equilibrium. Your results will vary depending on sequence, addition rates, and temperature. Batch data does not translate into a continuous process design.
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