Page 403 - Organic Electronics in Sensors and Biotechnology

380 Chapter Ten

100 nm

FIGURE 10.5 SEM of electrophoretically deposited nanostructured polyaniline
fi lm. (Reprinted from Ref. 9. Copyright 2007, with permission from Elsevier.)

patterning of polyaniline from its colloidal suspension has proved to
be a scalable technique: it can be applied to macroscopic substrates as
9
well as micro-fabricated device features. Recently, Dhand et al. have
reported the fabrication of nanostructured polyaniline films using
this novel electrophoretic technique. A mechanism for the conforma-
tional changes in the PANI chain during EPD has also been proposed.
Figure 10.5 shows the SEM of electrophoretically fabricated polyani-
line film with nanostructured surface morphology.
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Qariouh et al. have carried out a systematic study to investigate
the cataphoretic electrodeposition of polyetherimide from an aque-
ous medium onto an electrically conductive support (aluminum,
steel mesh). The subsequent steps were also investigated. The yield
and quality of deposited polyetherimide have been found to be
strongly dependent upon a number of formulation variables that are
closely related to the emulsion composition and electrodeposition
88
conditions. Ma et al. have applied classical colloidal theories that
describe the particle behavior in suspension to polymer particulates/
blocks. This suggests many possibilities in materials processing
including coprocessing of composites via particulate or powder route
to formulate complex microstructures. A polymeric material, poly-
etheretherketone (PEEK), has been used to examine the colloidal
behavior of polymer particulates by Ma et al. Zeta potential of the
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particulate suspension has been measured, and the electrostatic inter-
action of the particulates was examined by DLVO (Derjaguin, Landau,
Verwey, and Overbeek) theory. The electrosteric effect between the
charged particulates in suspension has also been studied. Based on