For example, what kind of solvent and what kind of processing technique shall be used to get the maximum possible dielectric constant (i.e. 50)
Salaam
I hope this paper will help you. It has the same composition and desired dielectric constant result.
This is not exactly my field but a dear friend achieved the results in his lab.
Take cares
Data Muneeb-ur Rahman Amir Ullah et al-2015-Polymer Engineering & Science
wasalam,
Thank you for the input. I am going to try the method mentioned in the paper.
You welcome. Currently, I am planning the same process but without copolymer and by using ceramics.
Professor Qiming Zhang at Penn State University published hundreds of papers on terpolymer and copolymer. they usually use DMF and dry it at 80 C. good filteration (1 um) is good. if cast on glass slide, you can soak the glass in DI water after 4 hours, then the film will be automatically peeled off without any damage. then you can further dry the free standing film.
thank you shihai for the answer, I will check their papers. Do they regularly get dielectric constant of 50?
The dielectric constant depends on the terpolymer compositions (NOT solvent). with optimized compositions, we can routinely get K in the range of 50-60 (peak value). The glass transition temperature of the terpolymer is below 0 C, so it is always fully crystallized when you form the film either by solution or melt.
Thank you,
You are right about the crystallinity, and also formation of alpha and beta phase depends upon the evaporation rate of the solvent. I have seen papers which talk about the effect of different solvents namely NMP, DMF, DMSO and combination of DMSO and acetone (attached is one such paper).
I have also seen a paper in which they report dielectric constant of nearly 60 for pure PVDF. I am attaching the paper for the reference by Tiwari et. al, you can also find their earlier work on PVDF and I would really appreciate if you can comment on the reliability of the results. For me, if they can achieve such high dielectric constant in pure PVDF, their paper should have been in Science or nature.
Thank you and I appreciate your time and effort.
many people do not understand dielectric and published hundreds of incorrect test results. Beta phase and alpha phase PVDF shall have similar dielectric constant.
for electrospinning of PVDF, the type of solvent may affect the phase structure.
For the terpolymer, its phase structure is determined by the composition and not determined by the solvent or preparation process. they will always be in alpha phase. we invented the terpolymers 15 years ago.
- Badges
- Science topic
- Similar topics
- Cell Biology
- Methods