i would say the same as Xinyu.. but they work good on glass substrate. U can even cast using brushing techcnique

It is possible. If you use camphor sulfonic acid used as dopant during chemical syntheis. the resulting polyaniline highly soluble in organic solvent. Then you can directly coated on petri dish or glass substrate. Other wise you can use secondary dopant like m-cresol.

I am using the same procedure as quoted by Xinyu sir. I am dissolving undoped form in NMP and then cast the films in petri dish. But i am not getting what i am expecting i.e. smooth and some what flexible film. I am also using electrochemical methods for the deposition of polayniline and polpyrrol films. But the same is not good in ITO. However, good in Platinum electrode but lack in reproducibility.

although many people say so (and here many people repeated), Polyaniline can not and will never form true solutions. Please have a look into this publication and references therein:

http://www.mdpi.com/2073-4360/2/4/786/

Everything which people consider to be a polyaniline solution in fact is a dispersion. Nevertheless one can form free standing films using such dispersions.

So could you Plz suggest me some method except electrochemical by which i can make polyaniline thin films.

here is another link for understanding the insolubility of Polyaniline:

http://www.organic-nanometal.de/www2/Research/soludisp/solabstract.html

there you can also find a link for downloading the full paper.

For making free-standing films: you may want to search in literature for publications by Alan Heeger et al, Epstein et al, MacDiarmid et al. There are plenty of procedures, they all go via "dissolving" (= dispersing) undoped PAni and add camphor sulfonic acid, and precipitate.

Ormecon (now part of Enthone) has different procedures but I suspect they may not sell small quantities for lab work.

I made a very quick google search, which is not a scientific search engine, you can find e.g. this one here:

http://www.dur.ac.uk/physics/staff/profiles/?mode=pdetail&id=545&sid=545&pdetail=52676

If you do not have specific requirements, you can take any route you find in literature, only you have to ignore "dissolved", but follow their procedures.

Another alternative is, you search for Ormecon patents, and you can find procedures therein as well.

I am working on synthesis and characterizations of polyaniline and polypyrrol. I am using chemical as well as electrochemical method for the synthesis of polayniline. I am very much familair with chemical route. Only difficulty faced is the formation of free standing film dissolved in NMP. I have gone through with litrature and many authors reported the same method for films. But in my case i am unable to get the film. Every time itis quite brittle. Infact i have discussed this matter people working in this field, but they were telling that its hit and trial method i.e. some time you will get good film or some time not.

Thank You very much for sending me such a nice article. Definitely it will enhance my knowledge in this regard.

you wrote: "Every time itis quite brittle. Infact i have discussed this matter people working in this field, but they were telling that its hit and trial method i.e. some time you will get good film or some time not." This is typical for dispersions, and I know those who published did not publish their failures. the point is you need to prepare really good dispersions of PAni in NMP first. You need to make sure the particle size in NMP dispersion is small enough, (measure by Laser Doppler method or light scattering), you should aim to be below 50 nm, no big particles above 300 nm allowed!

If you have problems to achieve this, I assume it is because your undoped PAni is not clean. You must wash and wash and wash and remove all (at least most) of the inorganic contaminations, resulting from polymerisation and from neutralising.

Don't use HCl as counter-ion for the polymerisation; take any other acid, but HCl is bad;

Plus, you need to use powerful dispersion techniques, like ultra-turrax, when dispersing the N-PAni in NMP.

you may also want to read this: http://www.mdpi.com/2073-4360/2/4/786/

and this:

http://www.organic-nanometal.de/www2/Research/abstract/a-noneq2.html

http://www.organic-nanometal.de/www2/Research/soludisp/Welcome.html

I was using HCl and H2SO4 as dopant for the chemical synthesis of polyaniline. Now, i will use some other dopant as suggested by you and take care of rest of the things. Hoping that i will get good film.

Thanks for your valuable suggestions.

With best regards

Vijay

You can prepare polyaniline thin films by plasma polymerization technique

Dear researcher, PAni usually we fabricated hot pressed film for measuring conductivity. Sometimes using other polymer binders but PAni particulates remain dispersed in the polymer used. I think dopants can also tried but one simple technique may be tried that is if solubility parameter of PAni is similar to the solvent used may work well. Pl. try.

Dr. Negi, as I explained above and for which I gave literature links; there you can also find what I described about solubility parameter of PAni which is far beyond any solvent's solubility parameter!

If you can derivatize the PANI, you can often improve the properties. As one example, an alkyl halide can be made to react with the amine moieties, and this helps solution dispersion and the consequent cast films.

How thin your film should be? You can tray to polymerize Ani with different protonic acids as DBSA, and o-TSA. But in my opinion the best one is CSA. I'm sure you can produce films with PANI-CSA but it will depends on your desired thickness.

proper dispersion of PANI in an appropriate solvent is neccessary. So first u can prepare is jst by doping within ultrasonic radiations and then u can spin cast. The ultrasonic radiations will reduce the particle size and it will help in preparation of better film.

Another way is making nonwoven with nanofibers, you can assembling extremely thin layers of PAni through eletrospinning process.

Generally you can use THF as solvent for PAni, then, let this solution in a ultra sound bath alternating with stirring procedures.

it is very simple.

PANI is sloved in NMP, under 60 in oven overnight.

the parameters can be adjusted to get better results.

it is very simple.

PANI is sloved in NMP, under 60 in oven overnight.

the parameters can be adjusted to get better results.

the picture in the attachment is the sample we prepared.

the thinkness can be 20 μm. the resilient and flexible film can be used in many fields.

Thanks D Chen for information. What type of parameters we can adjust??/

PAni is not soluble in NMP, however it forms a dispersion (a colloidal system) from which films can be made. Dengtai Chen, I assume you have used neutral PAni (Emeraldine Base) in NMP, correct?

https://www.researchgate.net/publication/253651172_Conductive_Polymers_as_Organic_Nanometals

Vijay Kumar wants to get conductive PAni film, I assume, or?

PAni-ES free-standing films tend to be brittle, the higher the conductivity, the more brittle.

Chapter Conductive Polymers as Organic Nanometals

content in NMP

Your comment was incomplete, can you resend?

to Bernhard Wessling ·

thePANI EB can solve in NMP solution.

PANI salt cannot.

The conducting polymer can be obtained wiht acid treatment. for the PANI can be made as salt on the surface. The inner of film is not made of PANI salt.

Chen DengTai, PAni EB is also not soluble in NMP, but forms very nice dispersions (colloidal dispersions), PAni-EB can show particle size around 10 nm then (sometimes below 10 nm).

You are right that an EB film deposited from NMP can be "doped" by acid, and such film will not be homogeneously be doped.

However, it is also possible to make doped film from dispersions of doped PAni (PAni ES), however, this is quite complicated to describe.

Vijai Kumar, you should search in my patents (patent list also on my RG page), there you can find some appropriate patent publications which will be useful. But as this is a complicated issue, you can not expect to get a simple answer here.

No pain - no gain!

Vijai Kumar and Chen DengTai, you can find a link to my patent list in this document here:

https://www.researchgate.net/publication/260427241_Milestones__highlights_of_the_Organic_Metal_Polyaniline_Science__Technology?ev=srch_pub

Article Milestones & highlights of the Organic Metal Polyaniline Sci...

@ Prof. B Wessling

Thank you very much for providing useful information. I am sure it will serve my purpose!!!!!!!!

There is a very simple method : 1) Dissolve polyalinine in a pure volatile solvent & get complete dissolution. 2) Bring a glass dish & place a cylindrical steel ring inside it. Pour mercury inside the ring. 3) Pour the polymer solution over mercury & let the solvent evaporate in the hood. 4) Pull the film with tweezers carefully.

If you succeed in casting a small film then you can proceed to forming a sheet but you need to change the method so that Hg is NOT used.

sorry, Mr. Matar, it seems you did not read the previous comments, nor the relevant literature. PAni is not soluble, definitely not!

I have published several papers about this topic, maybe this here is the most useful review:

https://www.researchgate.net/publication/253651172_Conductive_Polymers_as_Organic_Nanometals

Chapter Conductive Polymers as Organic Nanometals

Thanks Dr. Wessling for your comment. But, some scholars mentioned that it is soluble in NMP (but I shall agree with you that it is insoluble since you have good experience with the subject). I am now in doubt about what scientists said about its solubility in DMF, m-cresol, and HFIP (hexafluoroisopropanol) after you said that PANI is not soluble.

There must be a single solvent or a combination of solvents for PANI (at least when it has lower average molecular weight) but this requires research definitely. Thanks again Dr. Wessling.

I did not just simply "say", I have generated and collected experimental evidence, and I have analyzed other researchers' publications. This has been summarized here:

https://www.researchgate.net/publication/202290125_Conductive_Polymer__Solvent_Systems_Solutions_or_Dispersions?ev=srch_pub&_sg=0PoeBGxgQgaZo7sVIb8TaUxZjBW9lKMQjwsUnlaDuFXPw2UEZxkMCNIQRjh8HYqO_3nlUdFmODj55xYIFUTBI%2BG%2FSTHKZcUDfvDDlYGA2n1lXqaOTnx8lNrByP0CsGpcD

Some more here:

https://www.researchgate.net/publication/243341935_On_the_structure_of_binary_conductive_polymersolvent_systems?ev=srch_pub&_sg=krxlmOtpeef7GaT1fgA6aExo5C4shRH9fbEPuhygH81onF9MRc2%2BHe0JGKls%2BOGg_ew2DEi4KvLivLqpxs%2BPtrtT%2Fy%2FQZ26keTBZq3s4DEX3%2F18wfqw7x47mupGxhTzOn

If anyone can deliver consistent proofs of having a true solution (and not a dispersion = colloidal system), I will be the first to admit that I was wrong. But I think, the experimental evidence and its theoretical interpretation is consistent and sound.

This (to difefrentiate between "solutions" and "dispersions") is an important question as solutions are thermodanically spoken equilibrium systems, colloidal systems are non-equilibrium systems - you can imagine more serious differences. Such systems behave *completely* different, in every and any aspect!

Article Conductive Polymer / Solvent Systems: Solutions or Dispersions?

Article On the structure of binary conductive polymer/solvent systems

Dear all,

it depends on how thin is the film to be prepared, this means for example for the case of PAni-EB with particle size in solution around 10 nm or even below, if the film thickness is above the particle dimension there will be no problem, and the problem that may arise in this situation is the interparticle strength or cohesion upon drying, this means is the film really continuous and isotropic. Now for the second situation in which the film thickness is below the particle dimension, here we may refer to other techniques such us the sol-gel process or jet-spraying (combined effects of stress, solvent and temperature in film-forming).

film thickness can never be thinner than primary particle size (in case of EB: 3 - 4 nm, in case of ES: 10 nm). Plus, it is very unlikely if not impossible to prepare such thin layers, at least I never achieved, and I would also ask: why would one want to do so?

film thickness can never be thinner than primary particle size (in case of EB: 3 - 4 nm, in case of ES: 10 nm). Plus, it is very unlikely if not impossible to prepare such thin layers, at least I never achieved, and I would also ask: why would one want to do so?

I think Tetrahydrofurane,solvent  using casting technique

This papers may help you

1-Preparation and characterization of a conductive polyaniline/polysulfone film and evaluation of the effect of co-solvent

Hasan Farrokhzad,

Tom Van Gerven,

European Polymer Journal

Volume 49, Issue 10, October 2013, Pages 3234–3243Bart Van der Bruggen,

 "To improve the solubility of PANI in N-methyl pyrrolidone (NMP) and consequently increase the conductivity of the eventual film, a tertiary amine (1,3-dimethyl-2-imidazolidinone, DMI) was added to the solvent as a co-solvent."

2-Preparation of organo-soluble polyanilines in ionic liquid.

Niyazi Bıc¸ak  B. Filiz SenkalS, Esma Sezer

Synthetic Metals 155 (2005) 105–109

"A method for preparation of organo-soluble polyaniline (PANI) is described. Oxidative coupling polymerization of anilium chloride with ammonium persulfate in a newionic liquid, 2-hydroxyethyl ammonium formate (HAF), gives organo-soluble polyaniline with appreciable molecular weights (Mw = 86,400). Interestingly polyaniline (PANI) prepared by this method is highly soluble in many organic solvents such as acetone,tetrahydrofurane, dioxane, dimethyformamide and N-methyl, 2-pyrrolidinone. Thin films of PANI prepared at 0 ◦C (by solvent casting) showreasonable conductivities (up to 37.0 S cm−1) when doped with p-toluene sulfonic acid."

Again, it seems to me that I have to remind some of you about the FACT that PAni is not soluble, there is no conductive polymer which is soluble, all of them are principally insoluble. What you have when following papers like you (Iptisam Abbas) cited are dispersions, colloidal systems which are different from solutions like day and night, plus and minus, 0° and 180°, equilibrium and non-equilibrium.

I have generated and collected experimental evidence, and I have analyzed other researchers' publications and I have theoretically worked on this topic. This has been summarized here:

https://www.researchgate.net/publication/202290125_Conductive_Polymer__Solvent_Systems_Solutions_or_Dispersions?ev=srch_pub&_sg=0PoeBGxgQgaZo7sVIb8TaUxZjBW9lKMQjwsUnlaDuFXPw2UEZxkMCNIQRjh8HYqO_3nlUdFmODj55xYIFUTBI%2BG%2FSTHKZcUDfvDDlYGA2n1lXqaOTnx8lNrByP0CsGpcD

Some more here:

https://www.researchgate.net/publication/243341935_On_the_structure_of_binary_conductive_polymersolvent_systems?ev=srch_pub&_sg=krxlmOtpeef7GaT1fgA6aExo5C4shRH9fbEPuhygH81onF9MRc2%2BHe0JGKls%2BOGg_ew2DEi4KvLivLqpxs%2BPtrtT%2Fy%2FQZ26keTBZq3s4DEX3%2F18wfqw7x47mupGxhTzOn

If anyone can deliver consistent proofs of having a true solution (and not a dispersion = colloidal system), I will be the first to admit that I was wrong. But I think, the experimental evidence and its theoretical interpretation is consistent and sound.

This (to differentiate between "solutions" and "dispersions") is an important question as solutions are thermodanically spoken equilibrium systems, colloidal systems are non-equilibrium systems - you can imagine more serious differences. Such systems behave *completely* different, in every and any aspect!

Article Conductive Polymer / Solvent Systems: Solutions or Dispersions?

Article On the structure of binary conductive polymer/solvent systems

I just saw a typo, at the end it should read " you can NOT imagine more serious differences. Such systems behave *completely* different, in every and any aspect!"

I have read most of comments and part of papers listed. The conclusion which we should admit is preparing good solutions (not dispersions, colloidal systems) of PANI, PPY, or other conducting polymers is indeed a challenging issue. However, apart from free-standing film preparation, the fabrication of thin films of these polymers of reasonable thickness (< 200 nm) on substrates/wafers is not yet well established, fully admitted by the scientific community, and standard when one utilizes the commonly used film deposition methods- spin/dip coating.

I am really skeptical and reluctant to accept what is always claimed and argued that spin-/dip- coated films can be really achieved with plausible and reproducible physical properties that are required in many electronic and photoelectronic devices. The issues of homogeneity, uniformity, pinhole-/cluster- free, good adhesion to substrate, sustainable thermal and environmental stability, and in case of PANI, PPY films, and many other organic/inorganic films of technical interest- like perovskites, to have high electrical conductivity and optical transparency are still controversial.

As far as I know, other usual and efficient film deposition methods cannot be employed to deposit thin or intermediate thick films of polymers, even if they are being successfully produced as crystals or quality fine and homogeneous powders. Hope some experts and researchers in the field enlighten the situation further for me and/or provide me with fruitful suggestions, with many thanks in anticipation.

Mousa Abdul-Gader Jafar

Tuesday, 27th February 2018

Further, just to mention that PANI films can be obtained by the electrodeposition technique, but I believe that electro-deposited films may still suffer from same problems encountered in solution-growth methods.

Mousa, you should really read my paper about 'can conductive polymers form true solutions or one needs to prepare dispersions?'

it is definitely impossible to make true solutions, I have proven this in that paper.

Here is the link to a review chapter, it contains the paper I mentioned as a sub-chapter:

Chapter Conductive Polymers as Organic Nanometals

@Mousa, I have to agree with you on this point. It is notoriously difficult to obtain PANI films on substrates like Si or ITO/PET via spin/dip coating. We have tried spin coating Si and ITO/PET substrates with EB-PANI dispersed in NMP or DMSO without much success. The biggest problem we face is poor adhesion. In the end we try to functionalise the substrate surface through preheating but still we have to go through several iterations before getting a uniform film.