This paper has been submitted at Nov 4th, 1996, for publication in a
scientific journal and is now subject to the reviewing process.
You may ask for a hardcopy with the complete manuscript, which contains all figures and all
greek symbols.
Everybody
is invited to comment to this paper. I will consider every argument and
comment back.
This is the 3rd revised version.
Dr. Bernhard Wessling
Zipperling Kessler / Ormecon Chemie
D-22949 Ammersbek
6. Conclusions
It was the purpose of this article to present a complete description of all arguments supporting the position of
- "conductive polymers are forming dispersions (sols) with suitable solvents"
and the opposite hypothesis
- "conductive polymers can build true solutions with appropriate solvents".
Thermodynamic considerations - especially when looking at the enthalpic term in the free energy of solution - show, that the necessary introduction of the melt enthalpy as well as the necessary overcoming of the lattice energy will prevent any possibility of making true solutions.
The lack of direct experimental evidence for effectively solvated single chains is in accordance with these considerations.
On the other side, numerous experimental hints are available for supporting the "dispersion hypothesis". Thermodynamical aspects are conclusive according to which the surface tension of conductive polymers ("organic metals") is very high due to strong intramolecular forces, so that their primary and secondary particles will have solvents (water or others) adsorbed on their surface for reduction of surface energy.
Dispersed systems of ICPs/OM in solvents can be made as soon as the solvent is capable of reducing the previous surface energy.
Metallic conductivity and insolubility of organic metals (conductive polymers, which are polymeric salts) go together and are linked together, because they are based on the same intramolecular electronic interactions, hence very strong intramolecular forces.
