I suggest to look into Langmuir Blodget depostion technique. It is easy to implement and produces great results for such films. We have a leading expert in this field at the Physics Department at the University of Nebraska-Lincoln.

I completely agree with the Christian's suggestion. Prof. S. Ducharme is a leading expert in this field. I would like to mention some more experts for making PVDF/TrFE films -- Prof. H. Kliem, Lehrstuhl für Grundlagen und Materialien der Elektrotechnik, Mechatronik, Universität des Saarlandes; Prof. L. Blinov, Liquid Crystals Lab, Institute of Crystallography - the members of the group have pioneered the PVDF/TrFE Langmuir films preparation. I do recommend reading their papers. Some of them have films preparation paragraphs.

Than you for the suggestions.

Dear Suresh,

can you specify your needs for the P(VDF-TrFE) films? Glass substrate is very versatile in order to detach the polymer from the substrate. Solvent casting is a easy way to obtain micrometers thick films. Solvent evaporation will influence porosity, but also the TRFE ratio present in the copolymer.

Suresh,

may be it is too late, but anyway I would suggest glass substrates as Vitor Sencadas has already suggested and silicon substrates. Which one is better depends on your goal. For example, if your work concerns a thickness measurements a silicon substrate is better suggestion. In addition to casting method there are spin-coating and Langmuir methods. Again, which one is better depends on your goal. Langmuir is good for investigation of ultrathin films and interfacial effects.

Thank you for your suggestions, I would like to synthesize micron sized films by spin-coating technique which can be used for sensor applications. As I was getting highly porous films on glass substrates, so I wanted to know what are the substrates which will give me better results.

Hi Suresh,

I think that solvent evaporation is occurring at room temperature, right? If you make polymer spincoating on glass and quickly remove it to a hot plate at temperatures above the 100 ºC or above Curie Transition, the porous structure will not appear.

What you want is the minimum temperature to remove solvent from polymer solution to avoid porosity.

Yours, 

I don't think the substrate influences the porosity if its surface is clean and flat enough. Just try to use different concentrations or different solvents. Some of them evaporate quickly -- like acetone -- and others are not. Multilayered film would be a good idea if it is ok for your sensor properties. Just prepare one thin layer, dry it, then prepare another thin layer on top of it, and so on. This may reduce the porosity of the film.

Do you think screen printing is a good way to make thin film of PVDF-TrFE?

Also I am using a ratio of 65:35 for PVDF-TrFE, will that affect much of the properties of the film? I am testing it for piezo and pyroelectricity.

Dear Mihir,

I am right now synthesizing by solution casting and spin coating, hence I wish if some expert should comment on screen printing of PVDF-TrFE.

https://www.seas.ucla.edu/~pilon/P%28VDF-TrFE%29Synthesis.htm

You may take a look. Maybe it will be useful for you!

 Dear Suresh Ji,

This is Ramesh. I am planning for micropatterning of Copolymer film using dry film application. However, i have tried few but most of them are dissolving in DMAC that is in copolymer as solvent. Would you or any one can suggest a best solvent for PVDF-TrFE copolymer to make thin film as well as do not react with any photo resisit film while patterning. Patterning i want to use lift off process.

Please do have your suggestions.

Dear Researchers,

After gaining considerable experience in making PVDF-TrFE films, I am addressing this question.

Usually PVDF-TrFE  gives clear and transparent films compared with its homo-polymer PVDF when a solvent of DMF and acetone mixture is used while PVDF films are hazy/ milky in appearance due to the formation of pores when the same solvent is used. The random co-ploymer, PVDF-TrFE, can be treated above its Curie temperature and below melting point (around 140 °C) to exploit better ferroelectric properties. If the temperature is around/ above the melting point (of the polymer) and the substrate is glass the polymer films would have a higher tendency to adher to the substrate than their low temperature treated counterparts.

Usually PVDF-TrFE has a better adhesion to Al substrates and it also serves the purpose of acting as an electrode.

Dear Suresh Ji,

Would it be possible for you to give few suggestions for PVDF+TrFE micro patterning?

Thank you

Dear Ramesh,

I feel it would be nice if we discuss further in this regard on personnel mail. My mail id: [email protected].

Regards,