Hello,

maybe, you mean the ion hopping effects related to fuel cell membranes: vehicle and/or Grotthus proton hopping. If you search the web you will find explanations for theses effects.

regards

Peter

Dear Peter

Thank you for your response and suggestion

M. El Hasnaoui

Please specify more precisely. If you are talkong about composites with conducting inclusions and insulating matrix then the term probably refers to the charge transfer from one conducting zone to the other. If it is thermally activated process, then you will have a temperature dependent conductivity. The charge transfer may also happen via tunneling, in this case you may have even decreasing condutvitiy with increasing temperature especially near the melting point of the polymer. The term may also refer to the hopping of the charge carrier form one conducting chain to the other if the deloclalizaion is finite.

Dear Banhegyi

Yes, I am interested in tunnel effect in conducting polymer (EAB copolymer loaded carbon black particles) before and after the melting temperature, we have the conductivity decreases with increasing temperature (is called PTCR effect). If it is possible I need more explanation concerning the transport proprieties of these materials.

Best regards

Mr. El Hasnaoui

I have found two of your articles on the net, which I will read and I will come back with notes.

Regarding 22-JMES-86-2011-khissi it is a well written, interesting article. I missed only the grade identification of the carbon black used (manufacturer and type). From the 11% percolation threshold I assume it was a "high structure" black. I believe that some more details on compounding would be also useful.

The other paper 1-JMES-51-2010-Hasnaoui2 is somewhat more probelmatic for me. In Fig. 3. you show DSC curves, but melting is associated with enothermal peaks rather than with inflection points. (These latter are usually associated with Tg values).

Why are you particularly interested in ethylene-acrylate ester copolymers? Because of some mechanical properties?

Dear Gyory

- Yes you are right, The melting tempertrure corresponds the endothermal peak, it is near the inflection points( it was a mistake). The glass transition temperature of this composites was found in others works equal -75 °C. I am interested in EAB copolymer because the subjet of my preparation of doctoral degree ( I interested by transport preoprietes not mecanical).

- I am interested by other question that I received for correction other article, it is ( what evedence of cristallinity of epoxy DGEBF loaded BC particles, like X-ray , DSC, ....), I would like an article that used X-ray to show the critalilinity of epoxy-resin.

this is my mail: [email protected]

Thank you Sir for your interested

Sorry, I missed your answer. Epoxy resins are normally amorphous. Crosslinekd resins usually do not have enough order to crystallize. X-ray may detect, however the crystalline strcture of the filler in filled epoxy resins. Crystallinity may also be detected by DSC - if there is any.