Conducting Polymers - Science topic

The degree of crystallinity of conducting polymers affects the operation of organic field-effect transistors in a number of ways. The most important way is that it affects the mobility of the charge carriers in the polymer. The higher the degree of crystallinity, the higher the mobility. This, in turn, affects the transistor's on/off ratio, as well as the transistor's gain. However, low molecular conducting polymers are more useful for solution processed OFETs because they are more soluble in common organic solvents and have better film-forming properties. This makes them easier to process and results in better device performance. But, how can we use the rheological properties of low molecular weight conducting polymers to achieve high charge carrier mobility?

Many research papers mention using a solution of 0.1M aniline in 1M HCl or 1M H₂SO₄ as the polymerization bath for depositing a layer of polyaniline on the working electrode. However, the papers didn't mention the individual volumes of 0.1M aniline and 1M acid taken to form the solution. 

I mean to say, what are the selection criteria for positive and negative electrodes?

I would like to know what are the efficient method to prepare composite of conducting polymers with noble metal nanoparticle (Pt,Pd,Au) etc other than electrospinning method. Already the polymer has proved to have good conductivity and synthesized but the metallic nanoparticles has to be incorporated into the polymer.

Expecting valuable suggestions

A lot of the research papers that I've read are about the dependence of the morphology formation of polyaniline to the synthesis conditions but only found one paper that gives the idea that the morphology formation is independent of the application form. I would like to ask how strongly valid is the latter statement and what some more papers can support it.

Thank you in advance!

Hi all,

I am planning to disperse metal nanoparticles in superglue (cyanoacrylates) and acrylic adhesives. What would be the methodology for that? I guess just sonicating won't be an option since cyanoacrylate will start polymerizing as soon as it comes in contact with any nucleophile in the surrounding environment or substrate. What could be a more feasible option? Thanks in advance.

Thank you!

I want to prepare polymer composite containing conducting polymer and HNT through electrochemical deposition method. Please suggest suitable method to deposit HNT on conducting polymer (like PANI) through electrchemical deposition method

In the (electro-) conducting materials, as I know, there is an energy gap between the valence band (VB) and the conduction band (CB) that can be brought to or near-to the Fermi level by doping (p-type or n-type dopant).

But ( My question is ), If I want to design a (semi- or super-) conductor's materials (inorganic or polymeric) , Which properties would I look for? and, also, Which characterizations would I consider for the properties' investigations? What are the requirements for the materials' property (with regard to its band structure) to achieve the considered structure-property relationships (or requirements ) for the preparation of the conducting materials?

the composite matrix material is preferred to conducting polymer rather than non conducting polymer?

what's the reason behind it?

Like if the composite materials contains conducting polymer and metal oxides both, how to consider the formula for the calculation

I am trying to do a computational study for some conducting polymers I've prepared. I wonder if there is a cif file for polyaniline or polypyrrole (not derivative) since I've been searching for a while and I cant find it?

Although, several works have modified polyaniline with different nanocomposites and used in epoxy, I couldn't find any conducting polymers (polyaniline) being used in inorganic matrix. So, if anyone has any suggestions, that would be really great!

Thanks a lot

I have grown thin films (~100-500 nm) of PEDOT:PSS by electrodeposition on top of thin films of Au (~1 nm) and now I want to measure the impedance of the PEDOT:PSS thin film.

To accomplish this I am thinking of depositing another layer of Au (or another conducting metal) on top of the PEDOT:PSS for it to act as a capacitor and use 4 probe method to measure its impedance.

However I am apprehensive that by using a magnetron sputtering technique to deposit Au on top of the PEDOT:PSS thin film will alter its properties, rendering the impedance measurements not viable.

I can also do IBD deposition of Au, but I think this will be worse. I could also electrodeposit Au, however in doing that I needed to apply a negative potential which would reduce the deposited PEDOT:PSS rendering it non-conductive.

Opinions on how to deposit a conducting (can be very thin) layer on top of PEDOT:PSS without interfering with it ?

Thank you for your time.

I am working on PANi/PVA self-standing films. For that I have dispersed PANi source i.e. emeraldine salt dispersed in NMP and ultrasonicated for few hours and the centrifuged to settle down the heavy particles. Now I know PVA a non-conducting polymer is soluble in NMP so I add that in the PANi dispersed NMP and want to fabricate a self-standing film. Now for film fabrication the NMP should be evaporated completely and here comes my problem. The boiling point of NMP is above 200 degree Celsius so to dry it at room temperature is very difficult and if I heat the mixture then the film adheres with the glass petridish and it becomes almost impossible to peel it off so can anyone suggest me any solution for this? Thanking in anticipation.

Supercapacitor application

Could anyone suggest me some good papers which involves the coating or mixing of MXenes with conductive polymers such as PEDOT or PANI or any other conductive polymer for that matter.

Dear researchers,

Iam working on electrospinning device with cylindrical collector, i saw research used three layers covered the collector while another one used single layer so i wondering if the thickness affects on the fibers collected or not ?

What may be the reason/Argument for the increased dielectric constant with increasing temperature for Conducting Polymer Semiconductor nanoparticles?

Both are available in powder form need guidance for preparation of ink.

Dear friends,

I need equivalent circuit to fit in the electrochemical impedance data?

I have separate Equivalent circuit diagram for screen printed carbon electrode and polypyrrole on stainless steel. Kindly refer  the attached file.

With thanks and regards,

Eswaramoorthy K V

I have prepared PEDOT films on ITO by electropolymerization. I want to compare raman data of PEDOT films at various thicknesses since I observe change in its UV-vis absorption (dedoped PEDOT) spectra with respect to thickness (blue shift on increasing thickness). My films are in doped state and the laser I am using is 514.5 nm. Since doped PEDOT has very less absorption in 500-600 nm region, raman peaks are not very intense (no resonance). The only intense peak is ~1400-1450 nm which is for Cα=Cβ (thiophene ring) symmetric stretch. This peak is affected by change in doping state and conjugation of the ring. In my case I observe broadening of this peak for thinner PEDOT films towards higher wavenumber which is generally observed on increasing doping level. Is anything else can be interpreted from this data?

Thanks!

Regards,

Rekha

I am using PMMA based gel plasticized with propylene carbonate. This gel is sandwiched between two electrodes (coated with electrochromic materials). Our devices are getting dry very fast and the dried area doesnt show any color change because it is completely dried up. We have tried epoxy glue for sealing the device but that also doesn't work effectively.

Thanks in advance!

Regards,

Rekha

Hi,

I hope to hearing the comments from everyone on two basic issues about Cyclic voltammetry.

1. Firstly, I am doing a Cyclic voltammetry with a thin film of a conducting polymer (consider as supper capacitance) on the working electrode, a Ag/AgCl on reference electrode, and I am wondering if I should use a platinum plate or a piece of the same material as the working electrode for the counter electrode( make sure that the area of the counter electrode is always greater than that of the working electrode).

2. And secondly, the cyclic voltammograms showed that when I increased the scanning rate from 5 mV/s to 1000 mV/s with an increasing step of 20 mV, the Oxidation peaks shifted gradually to the right? I could not figure out the reason for this.

Is there anyway to test or verify that the polymer is intrinsically conductive or there is no any doping effects?

Please explain electron charge transport mechanism in conducting polymer having metal sulfide as fillers composite via energy band diagram / chemical property? We have synthesized conducting polymer having metal sulfide nanoparticles in it. We want to find the electron charge transportation phenomenon using energy band diagram or their chemical properties (electron affinity etc/ permittivity etc).

I have some glass substrates with a gold electrode pattern adhered using chromium. I drop cast or spin coat these substrates with a conducting polymer down the centre of the substrates so it covers the channel (gap in the gold). I then have to run a crosslinking step that involves submerging the whole substrate in an ethanol-water mixture. It's at this point that any gold exposed to the ethanol-water mixture will begin to detach from the glass and start floating around. The gold that is under the polymer sample remains attached (I assume because it is not fully exposed to the ethanol-water mixture and is thus protected?).

This might be a really simple question but is there anything I can do to make sure the gold stays attached to the substrates during the ethanol-water submersion? Or is there a suggestion of why the ethanol seems to lead to the gold detaching?

Thanks.

Good day! I'm working conducting polymer pedot:pss. I already done with preparing pedot:pss which is a water-based solution. I obtained 200 ohms resistance of that solution. Now my objective is to deposit a solid film on to glass or metal substrate. I tried spray pyrolysis heated at 90 C, however the deposited film achieved 3-6 megaohms of resistance its to high compared to 200ohms. So can you suggeat a technique to deposit pedot:pss maintaining its original resistance or having resistance not as high as 10kilo-ohms and above. (please don't mention spin coating I don't have that device) Thanks in advance.

Ammonium persulfate (APS) is used as a common oxidant during chemical polymerisation of polyaniline and other ICPs. I wonder if the oxidant itself can dope the polymer during polymerisation (like the thing happens when we use FeCl3), since during reaction, APS is known to be converted to sulfate radicals and then anions, which are able to protonate the polymer even without the presence of acids such as HCl and organic acids.

I am asking this question because many papers suggest doping of polyaniline by mixing the dopant (organic acid, polymeric acid, etc.) within the reaction mixture (containing aniline as monomer). However, if this is the case and the oxidant is able to dope the polymer, there would be competition between sulfate anions (by APS) and other anions produced by the organic acids, and it would be impossible to attain a pure PAA or PSSA doped PANI or a pure CSA-doped PANi.

[Of course it is possible to first dedope the PANI with strong bases and then redope it with the desired acid which seems to be more rational]

Hello all,

For the past week I have been working on a new electrode, the process however uses a double solvent cast in the construction of the electrode.

Initially a layer of CNT + Nafion in isopropanol are cast and dried at 100 degrees centigrade for 30 mins, this is followed by a cast of a mediator suspended in pure DMF.

Regardless of DMF having greater miscible properties than isopropanol, I'm curious if there is potential for the DMF to lift the first layer into the solvent?

Any advice will be greatly appreciated.

During synthesis I found that when APS is added to a solution of Ani + HCl, even small amount of APS is sufficient to form the green color to solution. Of course the rate at which PANI is formed is different and increases with an increase in APS. Fresh HCl and Dist. Aniline were used. To what extent does the chemistry change and what are the possibilities that the other forms of PANI are forming?

Is it possible to dope a pre-made film of a conductive polymer that was synthesized without the dopant electrochemically? Additionally I was wondering if anyone has selectively doped/undoped the polymer electrochemically?

conduct polymer structure

Hi, I have synthesized Poly(3,4-ethylenedioxythiophene) (PEDOT) by chemical oxidative polymerization method,using APS as an oxidizing agent, as conducting polymers are not soluble in water. Suggest me the solvents for dispersion of PEDOT. Thank you.

Dear all,

We have measured the electrochemical impedance of a conducting polymer and we would like to obtain the specific capacitance in term of F/g. The data from the EIS were fitted with an equivalent circuit. We also have Nyquist and bode plots are at our disposal.

I just need this value in order to compare with the literature.

Could you please recommand me some ways to calculate it ?

Thank you for your attention.

The literature on thermoelectric transport of charge carriers for amorphous systems is a bit scarce.Also, it is very confusing as to what the current model of transport of charge carriers for such systems are. Is it percolation?, is it hopping?, is it phonon drag?

Sub questions:

1. Why is the thermodynamic point of view of diffusion (used to introduce the subject) not a widely accepted view?

2. Which view is the most widely accepted now?

a. Phonon drag

b. Hopping

c. Percolation

1. I have plotted log ac conductivity vs log frequency to find out power factor, S. I am getting S values (ie, slope of graph) below 1 for some samples and S values (ie, slope of graph) above 1 for some samples. wheather it is possible to get S values above 1. what may be the meaning?

2. set of sapmles with S values below 1 follows different trends. ie, in some cases S values are independent of temperature where as in some cases S values linearly increses with increase in temperature. Can anybody can explain?

(All the samples are bioplymer based composite containing conducting polymer as filler in low wt%)

For example electrodeposition of an oxide film by potentiostatic method on a conducting polymer such as polyaniline or polypyrrole.

I am working on the synthesis and application of conducting polymer based supercapacitor electrodes. Can somebody provide some brief knowledge about different factors responsible to increase the current response in case of the supercapacitor electrodes. In case of cyclic voltammetry, we apply some potential and current is generated. How to increase that current response?

I modified an electrode with a layer of conducting polymer

what are the analysis techniques that I can use to characterize the polymeric film?

How could I measure the thickness of this polymer layer?

Thank you in advance

As can be seen from the graph, there is a broad and low peak with an up exo arrow. I'm not sure what the respective process was and looking forward for any suggestion.

If u know pls give me the infor mation

I have actually conducted experiments and solution of polypyrole and polypyrole doped with different dopants gave me great results.I was able to sense ammonia roughly upto 10 ppm. But , a question always arises that due to solvent present other than the conducting polymer there will be random changes in conductivity which increases error so how to minimise the error if we want to proceed with ammonia sensing using a polymer solution

During the measurement of I-V curve in a metal-organic Schottky junction diode, getting lots of fluctuations. I have attached some files here. Need suggestions to avoid this thing. Tell me the physical reason behind it and the parameters I need to improve. (voltage ranges from -3V to 3V, data point 50, compliance 0.01)

Thanks.

By looking at the structure of both molecules, I see that both molecules have at least two non-conjugated sigma bonds, making conductivity due to resonance seemingly impossible. I read from this paper " " that the conductivity of polystyrene is about 6.7*10^-14 S/m and polypropylene should have a conductivity somewhere between 10^-18 and 10^-17 S/m.

Some things I didn't consider is the density and porosity of the materials and possibly inter-molecular effects.

Conducting polymer composite shows enhance electrical and magnetic properties

The nano- and micro-particles of noble metals, such as Ag, Pt and Pd, entrapped in a conducting polymer film were extensively used for preparing functional electrodes for sensing purposes due to their intrinsic catalytic properties, high electrical conductivity, good chemical stability and new physicochemical performances that are different from those obtained in the bulk state.

By my question, I would like to know more about the application of these composites for fuel cells technology.

I have prepared conducting polymer films on ITO of height nearly 30 nm. They are showing crystalline nature in XRD spectra. I want to analyse the degree of crystallinity and polymer chain orientation on the films. Please guide me and give some suggestions.

Thank you.

I have prepared a composite of PANI (conducting polymer) and silver NPs by simple mixing method. This mixture will show same properties as those of Polyaniline (PANI)/silver (Ag) nanocomposites prepared by several other methods or not.

I have done the reaction at 0 degree. The substituted group affected the polymer yield. Is it possible to increase the yield of the substituted polymer group by oxidative polymerization method?

Hello everyone,

I would like to compute what temperature my pressed organic powder-based pellet reached after the application of a high voltage (max voltage around 250 V, experiment carried on at room temperature). I though to use joule effect formula and to equate it to the usual Q=m*C*(T-T0). This is however an abrupt method...do you ever know a more reliable one? My material is a natural polymer which exhibit both ionic and electronic conduction. It can be considered as a conducting polymer (low conducting anyway).

Finally, could anyone of you indicate me where I can find a complete table chart showing the thermal properties of solid conducting polymers (particularly the specific heat) ?

Thank you very much.

Hello all,

I've been trying for a while now to crosslink dopamine to chitosan using various means, more recently I have been using glutaraldehyde.

My electrode is made in house using an ink from Gwent. It seems that once printed the ink is very susceptible to attack from a variety of solvents, such as acetone, toluene, etc. I've mainly used alcohols (solvent cast) and electropolymerisation/deposit to layer my electrodes.

I've been trying to link the two amine groups of the chitosan and dopamine but have been having issues. This most recent one affects the structural stability of the working area of the electrode.

Protocol:

Now the next step would be to incubate in a poly dopamine solution pH 9.0 at 37 degrees centigrade for 3 hours but the electrodes seem to 'crack', and lift from the substrate surface in some cases, almost slightly desiccated?

Can anyone point out the error in my protocol or offer some useful advice?

I have previously tried electrodepositing chitosan to the electrode, which resulted in uneven coating due to bubbling at the surface.

Regards,

Craig

The copolymer of aniline and pyrrole (1g : 1g) were synthesized by dissolving it in 100 mL HCl (1 M) and using APS (4.8 g in 100 mL HCl (1 M)) as an oxidation agent. The polymerization were done in 0C in N2 atmosphere with stirring for 24 hrs.

The obtained product contain white, brown and green impurities that don’t dissolve in any of the following solvents: HCl, Methanol, Ethanol, and deionized water

So, how could we purify the polymer from these impurities?

Industrial scale applications of metallic SWCNTs

Conducting Polymers

I m doing my project on this topic I need some recent work on this topic..

Good afternoon

In recent days, I have made a  synthesis by CV of a conducting polymer in a specific electrode. Then, the follow swep is to calculate the thickness of the film using the following equation: 

archive jpg

The doubt in this expression is which charge I should to use to determinate the thickness of film using this equation?

I have think that is the charge asociate to the oxidation but i have discrepances in if is the chargue of all voltamogram or only one portion itself.

thanks for you attention

Looking for a suitable polymer type material to coat flexible fuel lines for an under sea fuel delivery system.   

We pretend to use 3-4-dymethylpyrrole as a monomer for conducting polymer. Nevertheless, we haven´t found any reference, concerning its synthesis and(or) polymerization. Do you have any suggestions concerning its synthesis?

Especially in systems where organic molecules act as donor and carbon nanomaterials act as acceptor.If the organic molecule is fluorescent, how the current /conductance modulation in nanomaterial get influenced.

like with polyaniline doped with acids

As I was preparing the electrode for lithium ion battery,  I tried taking 70% active material (70mg) ,20%(20mg) pvdf binder (20mg/20ml) ,10%(10mg) carbon black as conducting additive. I kept it for dissolution for 8-10hours but still proper dissolution isn't done. 

I want to calculate the theoretical conductivity of levodopa molecules @pH=7. How can I do that? Please suggest me some procedure. 

Please help me to study the transport properties of ionic liquid doped polymer electrolyte

I want to synthesize polyaniline from anilne. I have read that aniline needs to be distilled before being used in the polymerization process. How do I get distilled aniline from aniline

We want to protonate the polyaniline with CSA for gas sensor. I would like to know that what is the best ratio of CSA/ polyaniline for better protonation of polyaniline as a gas sensor?

I have polyaniline (Emeraldine salt; >15.000Mw), I would like to know, if somebody can recommend me a way to disperse it. For a sensor application then.

Many Thanks

What is the best conductive EO/Li ratio in PEO based electrolye?

I have a new idea toward molecular electronics 

What are the possibilities of measuring whether the material is more or less "p-type"? (for example conducting polymer and reduced graphene oxide and the composite)

Conducting polymers like Poly aniline shows a dispersion in conductivity when the frequency is changed.what is the reason for this dispersion in conductivity?similarly there is a dispersion in the case of permittivity as well.Can anyone please suggest the reason for the dispersion of these intrinsic parameters ?

I know that the measurement involves measuring the onset of photopotential. Does this involve just measuring a voltage when light hits the electrode and measuring the voltage against a reference?

Can this be done for a nanoparticle? Can the valence/conduction band of a nanoparticle in a solvent be measured?

EDIT: To clarify, I am talking about band bending not a change of the size of the bandgap but a change of the valence/conduction band.

I had some PEDOT:PSS dispersed in water freeze and thaw, resulting in large PEDOT:PSS beads that do not pass through a 0.45 micron PTFE syringe filter. Is there a simple method to break up these aggomerations to a workable size for spin coating? Is it advisable to sonicate the dispersion at warm temperature?

Thanks

I am trying to fabricate a carbon black (Ketjenblack EC-300J - AkzoNobel) doped narrow width silicone (Sylgard 184) film but the film develops cracks (as seen in attached image) as it begins to cure at room temperature. What might be causing the cracking of this conducting layer?

If you need any more details about the process in order to answer this question then please let me know.

Researchers who are expert in the area of conducting polymer nanocomposites