I am planning to measure the conductivity of polypyrrole with some other compound. I have used HCL doped solution of polypyrrole which has not good solubility.
calculate the solubility parameter of polypyrrole, and dissolve it in a solvent with a similar parameter.
Hcl makes ppy a poor soluble, try it with other dopant, Organis dopants like Dbsa will help, or try with m-cresol or NMP, it may work (after partial dedoping of ppy with ammonia).
The solubility of polypyrrole (PPy) is highly restrained, owing to the extensive cross-linking of the polymer backbone. Neutral PPy is generally considered insoluble, but it can swell when exposed to some solvents. Once swelled, PPy can be doped, either in acid or basic media, with some charge-compensating anions (e.g. OH-). The doped PPy can be dissolved in a few solvents, such as chloroform, dimethyl sulfoxide (DMSO), m-cresol, N-Methyl-2-pyrrolidone (NMP), and tetrahydrofuran (THF).
Polypyrrole is absolutely insoluble, as any other conductive polymer. You can find experimental and theortical (thermodynamical) proof for this in my papers, especially in some subchapter of this handboook chapter:
https://www.researchgate.net/publication/253651172_Conductive_Polymers_as_Organic_Nanometals
Chapter Conductive Polymers as Organic Nanometals
what most people call "solubilize" or "solution" in connection with conductive polymers are any and all dispersions = nanoparticle disprsions = colloidal systems. In my above cited publications and in several more, I have described what these are and why they are this way and how they can be made.
Those interested at this question subject may also want to check additional answers given elsewhere at this forum: https://www.researchgate.net/post/How_can_I_convert_solid_polypyrrole_powder_into_liquid_form
no conductive polymer is soluble, they are all insoluble, but they can be dispersed (conductive polymer nanoparticles between 10 and 100 nm size if the dispersion is well made).
However, Polypyrrole is the worst you can chose, its chemistry (chain structure) is not well defined, not regular, too many crosslinks etc, it is the worst conductive polymer I have ever worked with.
For some deeper introduction, you can read this handbook chapter:
https://www.researchgate.net/publication/253651172_Conductive_Polymers_as_Organic_Nanometals
and you may search more publications on my RG site.
How can I convert solid polypyrrole powder into liquid form? - ResearchGate. Available from: https://www.researchgate.net/post/How_can_I_convert_solid_polypyrrole_powder_into_liquid_form [accessed Sep 4, 2015].
Chapter Conductive Polymers as Organic Nanometals
Raj, as polypyrrole is not soluble (insoluble in any solvent) the only what you can achieve is a colloidal dispersion, which is very complicate with PPy (usually, one can only get some by-products in form of a good dispersion).
In case you could succeed to get a fine dispersion, what GC-MS does is to separate fractions of different adsorption/desorption behaviour. You will find some purple coloured fraction which is not PPY but a b-product. Most probably, the real PPy product will not run on GC-MS column but just stay on the top.
Shradha, I think you misunderstood Raj's question. I understood he wants to confirm what he got is Polypyrrole, and he wanted to use GPC (Raj, yes?), and I disagreed.
If I understood well, Raj, you should used IR (FTIR), UV-VIS of your dispersion, and elemental analysis.
yes, I agree, GC-MS is not useful.
Please explain what you mean with "i am only getting 32% no hit compound"
Most polar solvent are good to dissolve Polypyrrole such as (DMF, NMP, DMSO and also m-cresol), where you can mixed these solvents or use them separately.
Good Luck
Gailan, it seems you may not have read previous comments - quite some time ago, I wrote the following:
no conductive polymer is soluble, they are all insoluble, but they can be dispersed (conductive polymer nanoparticles between 10 and 100 nm size if the dispersion is well made).
However, Polypyrrole is the worst you can chose, its chemistry (chain structure) is not well defined, not regular, too many crosslinks etc, it is the worst conductive polymer I have ever worked with.
For some deeper introduction, you can read this handbook chapter:
https://www.researchgate.net/publication/253651172_Conductive_Polymers_as_Organic_Nanometals
and you may search more publications on my RG site.
Chapter Conductive Polymers as Organic Nanometals
Bernhard Wessling !! Could you please tell me how can increase the conductivity and solubility in the same time for polypyrrole by sulfuric acid doping
sorry, Gailan, it is impossible to improve conductivity and solubility of polyprrole:
1) PPy is - like any other conductive polymer - insoluble and can theoretically only become dispersed
2) for dispersion, PPy is the worst conductive polymer I had every worked with: the polymerisation reaction leads to many side products, the chain is irregular, there are crosslinks etc ... a nightmare
3) this is also the reason why doping of PPy (with any dopant, also with H2SO4) leads to only moderate conductivity results, and I never succeeded to improve it.
Thank you so much Bernhard Wessling. That what I get it too with this polymer, So how about mixed two sulfuric acid with polypyrrole such as NSA and CSA, where one increase the conductivity (CSA) and one increase the solubility NSA or DBSA.
thank you
please understand: you CAN NOT increase solubility. Did you ever read any one of my papers regarding insolubility of conductive polymers?
I suggest you skip working with PPy, take PAni!
here is something you should read
Chapter Conductive Polymers as Organic Nanometals
to make GPC, it does not make sense! because it is not soluble! you can not determine molecular weight in GPC because the standard (polystyrene) with which you want to compare, is soluble, but your PPy can not be dissolved; so, in GPC you can only determine the residence time of the dispersion on the GPC column (the smaller the particles, the longer the residence time), but you can not get any Mw information from it; any such publications in iterature (mostly on PAni) are simply wrong, inappropriate.
for NMR:
for NMR, you also need to consider: in dispersion, you just have small particles, the better dispersion you have, the smaller the particles are; it may be possible to generate NMR spectra when using deuterated DMSO as dispersion medium, but I don't know how well resolved the spectra will be.
Ahsan, 3 answers:
1) the link works well, I checked it, please try again; it will tell you and your professor WHY conductive polymers are not soluble and can not be soluble
Chapter Conductive Polymers as Organic Nanometals
2) to your question " if it possible we copolymerized pyrrole with 3-hexylthiophene then there solubility is improved or not,,, and then we determine it by NMR and GPC? "
no, only apparently solubility can be improved, but in fact, if really optimally made, you will end up in a kind of system like "soap in water", which is also not a solution; what you (and your professor) need to consider is that these polymers can principally not be possible, due to their delocalized electron systems and the positive and negative charges bound to the polymer chain (pls check the article above!)
3) to your question " but not determine these polymers by NMR and GPC bcoz not soluble in any solvent,, what should i do "
you have to make dispersions!
and what do you want to determine?
look at this article: Article New Insight into Organic Metal Polyaniline Morphology and Structure
I can not send you the chapter, it should be possible to enter it on my RG site. Alternatively, you may read this article which is a subchapter of the review which I cited above:
Chapter Conductive Polymer / Solvent systems: solutions or dispersio...
Polypyrrole is well dispersed in DMSO. But you can use surfactant during synthesis to be soluble in DMSO.
not "soluble"! when using surfactant, it will be easier "dispersible"!
totally agree, 'cause polymers normally swell in the solvent environment instead of dissolution such as powders or salts ,....
but, please be aware, conductive polymers like polypyrrole even do not swell, they are 100% insoluble!
but Mr Bernhard, some papers I found, they tried to make a film by mixing PPy into solvent m-cresol, how about that? Plz help me to answer
yes, "mixing" PPy with m-cresol for making film can be successful, and if so: PPy was finely *dispersed*.
Please read chapter 1.2 in this book here:
Chapter Conductive Polymers as Organic Nanometals
Just additional comment: PPy is the worst conductive polymer one can choose for research as does not hjave a clean structure, lots of side products, very bad properties if its dispersions, I had stopped looking at PPY and completely focussed on PAni which was successful, and I brought PAni to the market where it is still in use, and maybe soon even more.
Thank you Dr. Wessling for your excellent answers! The Sandhill Cranes are building new nests here in Missouri! Gorgeous!
Allen Engel haha, a wonderful combination of polypyrrole / conductive polymer topic and cranes topic - how comes, are you interested in cranes as well?
I am excited about the potential for conductive polymers to reduce the use of heavy metal pollutants in the environment.
Sapana Jadoun
Pandian Kannaiyan sorry, to both of you: PPy is definitely not soluble at all, what can be done is to disperse it. So one can make a colloidal dispersion. But with PPy, these are not very good.
early days researcher prepared polypyrrole by electrochemical approach but recent days many people have synthesised polypyrrole in soluble form using different dopants like lignosulfonate and polystyrene sulfonic acid. Many people are working to develop thinfilm coating and sensors. Even lignosulfonate doped polypyrrole dispersed in water
Pandian Kannaiyan that's fine, but these are not solutions, so you can not say "soluble form"; these are colloidal dispersions. Please check my RG site for understanding the difference. If you don't know what to read, maybe you start with that one here:
Chapter Conductive Polymers as Organic Nanometals
Solutions and dispersions are in fact completely opposite systems, and later maybe this as well:
Article Dispersion hypothesis and non-equilibrium thermodynamics: ke...
and look at this one:
Article Critical Shear Rate - the Instability Reason for the Creatio...
Sapana Jadoun
I can and I must tell you: there are hundreds, if not thousands of papers claiming to have "easily soluble" conductive polymers, PPy, PAni, etc etc. None of them, not a single one, has ever shown particle size measurements.In the 2nd subchapter of this chapter
Chapter Conductive Polymers as Organic Nanometals
I have detailed what you need to find if you are dealing with true solutions.
Plus I have shown that it is principally impossible to have truely soluble conductive polymers. Please read the paper in the above link and digest it.
What people see and believe are solutions, are in fact colloidal dispersions: they *look* like solutions (for the naked eye and even in microscope), but in fact you have a fine colloidal dispersion with particle size between minimum 10 nm and usually around 100 nm, depending on the degree of dispersion.
Sapana Jadoun
Anyway, you can send me the article (send me the link to this article), and I can comment then in detail for especially that article
you can be 100% sure that I am telling you the scientific truth: it is thermodynamically absolutely impossible to have truely solvated conductive polymers, that you can read in the chapter for which i gave you the link
Bernhard Wessling, I totally agree with you, and the reason I couldn't make it into fibers is because it's not a true solution but dispersion particles. Regarding Ppy, your explanation is very helpful, but I prepared a red solution-like Ppy, an olive opaque Ppy, and an ultra-high conductivity Ppy with something over 1200 S/cm. Once I get a transparent Ppy or close to it, I will publish it.I consider Ppy to be a real challenge worth addressing
Muaathe Ibraheem very interesting, thanks for your answer, and as soon as you are ready to publish it, please send me a preprint or a copy (a link), I would especially be interested in the chemical parts before you are dispersing it, and in the dispersion process parts.
The chemical part is interesting for me, as different colours are a hint to me that there is different chemistry involved.
And may I ask: what are the particle sizes?
Hi Kunal, most polar solvents are used to dissolve Ppy, for example, DMSO and DMF.
Shams B. Ali strange - had you ever done this yourself? if so, have you ever checked whether what you may have thought looks like a solution is really a solution?
Are you aware of the differences between a solution and a colloidal dispersion? (both are in fact stark opposites)
You may (not) want to study this deeper, but let me tell you: conductive polymers including polypyrrole are principally insoluble, you can definitely NOT dissolve them, i. e. prepare a true solution with dissolved single PPY chains.
What one can do is to prepare nanoscopic (colloidal) dispersions. Not easy, but possible.
You may go with solid-state conductivity measurements, either two or four-probe methods.
It's impossible to measure liquid state conductivity unless you are determined about it.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials Chemistry
- Polymer Chemistry