Dear Ahmed:

Thermal de-doping in conductive polymers is a change in the structure of the electrically conductive polymer under the influence of temperature. See attached file. It is like adding and removing impurities that affect the electrical conductivity.

Best regards.

De-doping means removing the charge carriers from the conducting polymers. It can be done by reversing the charge carrier formation reaction e.g, in polyaniline it can be done simply by treating acid doped polyaniline with a base.

in case of PAni, "doping" is done using acids. (the term "doping" is wrong, but widely used; "doping" in semiconductor physics is a term describing that a trace of a foreign element is introduced which dcreate charge carriers; in conductive polymers, the acids - or in case of other conductive polymers: oxidants - are introduced in a molar ration 1:0.5 / monomer unit : acid/oxidant).

"dedoping" means to remove the acids (in case of PAni) or oxidants.

I would like to add few points to what Dr Wessling had stated. 1. Doping of conjugated polymers may be done not only by oxidation but  also by reduction in some cases e.g., polyacetylene and  poly(p-phenylene) may be doped also by reducing agents i.e., by adding some extra electrons into the chain backbone. 2. Be it oxidation or reduction, it must be partial e.g., to the extent of  10 to 50% of repeat units. 3. Even though polyaniline is doped by acids the polymer is half-oxidized by suitable oxidants before that.

Thanks all for these informations. @Prof Yuri Mirgorod, @Dr Wessling, @Prof. Broja Mandal

I got your answers. And, I'm still wondering about dissipating the coulomb charge which were emerged in conjugated polymers and caused the surface roughness and holes !.  Is the dedoping "=to remove the acid" will remove the deformations after flushing out the components "impurities"? , and am I've reverse (full recovery) tautomerizmation?, also in the case of repeat unit's extension: Is this extension ratio (10 to 50%) come from the dopant size or they're another parameters, because the liquids cannot crystallize ? 

@ Broja Mandal: I agree partially, pls allow me to comment:

1. reduction: to my knowledge, there is no stable reductively doped conductive polymer, maybe I did not see most recent publications, if you can show one, pls do so! thanks.

2. Polyaniline does not need to be oxidized before (acid) "doping", the normal oxidation state which you get after (oxidative) polymerisation is the state which simply gets protonated while contacting with acids, and when dedoping, you only neutralize the PAni with no electron transfer (no reduction ongoing).

There is a reduced state of PAni, called "Leucoemeraldine", this is not stable in air and will quickly be reoxidized by air to the Emeraldine state (neutral or acid doped one)

@ Ahmed MS Dawelbeit: Maybe I did not fully grasp your question, anyway I try to answer:

during dedoping, there will be no tautomerisation, also no rearragement of the chain; the chain is rigid and not at all flexible (I describe a clear example: in case you polymerize Aniline to form PAni in presence of optically actve acid, like (+)-Camphor sulfonic acid, the doped PAni will be optically active, very strongly so!

But PAni has no optically active C center, so you may believe the strong optical activity results from the incorporated (+)-CSA - wrong! (that PAni has a much stronger, by orders of magnitude stronger, optical activity than even concentrated (+)-CSA alone!)

Now we remove CSA by using a strong base: the resulting neutral Emeraldine base (EB) is still very strongly optically active!

How that? my explanation for this is: the PAni chain is helical, by polymerizing in presence of (+)-CSA, only one helical direction is preferred leading to optical activity, and when removing the acid, the chains remain in that form and don't rearrange!

See also this here:

https://www.researchgate.net/publication/49593603_New_Insight_into_Organic_Metal_Polyaniline_Morphology_and_Structure

Article New Insight into Organic Metal Polyaniline Morphology and Structure

 @ Bernherd Wessling: Yes, it is true that reductively doped conjugated polymers  are not stable in air and / or moisture. However, some of them have shown considerable promise.  Refs;  Angew Chem Intl ed. 2012, 51 (issue 36), 9042; Macromolecules  2010, 43, 9348. These are not the most recent publications though.