The ICSM is an International Conference held every 2 years, covering organic
conductive systems (from graphite and fullerenes over donor-acceptor complex salts up to
conjugated and conductive polymers). Ormecon's managing partner and president, Dr. B.
Wessling, is member of the International Advisory Board since many years.
Ormecon scientists present 2 papers and are partners in research for 4 more
papers:
B. Wessling, P.
Kahol et al (oral presentation): ESR and magnetic susceptibility of PAni/PMMA blends
The study shows that the amorphous shell of the primary particles (containing
the metallic core) is reduced during dispersion, and in contrast to the undispersed raw
PAni (where only localized bipolarons are present in the shell), delocalized polarons are
available. This is in line with earlier findings that PAni in such blends crosses the "insulator-to-metal transition" to
the metallic side. The enormous density of state at the Fermi level (compared to much
lower values for other PAni in literture) was confirmed indicating that a high charge
carrier density is also necessary for the IM transition.
W. Lennartz, G.
Nimtz, B. Wessling et al (oral presentation): Morphology changes in PAni/PMMA blends
studied by SAXS
The mesoscopic morphology between 1 and 100 nm was studied. It was found that
the primary particle (around 10 nm in size) consists of entities of 3.45 nm diameter. It
is concluded that these are individual molecules forming the primary particle, which
itself contains an about 8 nm big
metallic core. This means, that about 8 (crystalline) molecules aggregate to form a
homogeneous metallic space. It was found that the primary particles significantly decrease
in diameter with higher concentration and conductivity. Secondary particles (agglomerates
of primary particles) are found with up to 60 nm in size.
J. Posdorfer, B. Wessling (Poster):
Oxidation of copper in the presence of the Organic Metal polyaniline
A quantitative study is presented showing the passivation of copper by our PAni. Whereby
etching with sulfuric acid leads to a continuous increase of Cu(I)- and Cu(II) oxides
[with f(t)], PAni forms a complex with Cu(I), and the Cu(II) oxide is formed at a slower
rate [with f(t1/2)] reaching a finite thickness much thinner than
when oxidized after acid etching.
H. Ladebusch, T. Strunskus, J. Posdorfer and B. Wessling (Poster): Chemical
interaction at copper/polyaniline interfaces
more basic analyses on the reaction mechanism between PAni and copper.
G. Rangarajan, B. Wessling et al (Poster): Low temperature sensor with PAni/PMMA
blend
Advanced results from studies of the conduction mechanism in these blends, which are
on the metallic side of the IM transition, and
description of a potential use of such blends as cryomagnetic low temperature sensors.
G. Delmas-Patterson, B.
Wessling et al (Poster): Calorimetric studies on PAni-NMP dispersions
Between 70 and 90° C, an exothermic phase transition is found for the interaction of NMP
with PAni. Depending on concentration around -2,000 and -20,000 J/g, resp., have been
measured (the higher value for the lower concentration, indicating a higher specific
surface area accessible during dispersion to smaller particles at lower concentration). We
assume that the energy represents the exchange of the adsorbed water layer (on the
colloidal PAni particles) by an NMP layer including the solution heat of water in
NMP. At lower T, before this phase change occurs, NMP is obviously wetting the water layer
around the PAni particles.