a) b - École Polytechnique de Montréal

prepare a polymer blend structure with large fully interconnected phases. Subsequent extraction
of selected phases within that blend would thus allow for the preparation of a very low surface
area, fully interconnected, porous polymer substrate(Figure 5-1). As will be shown below, the
most effective route towards this is via the preparation of a multi-percolated, multi-component
polymer blend.
a) b)
Extraction of phases
Deposition of PSS/PANI layers
Figure 5-1. 3D schematic showing the approach used to prepare the porous polymeric conducting
device via LbL deposition. (a) solid multi-percolated structure comprised of HDPE, PS, PMMA
and PVDF after melt blending and annealing; (b) porous polymeric conducting device after
extraction of PS, PMMA and PVDF, followed by LbL deposition of PSS and PANI.
Recently(J. Zhang, et al., 2007), it has been shown that a ternary co-continuous (double
percolated) morphology could be developed in which hierarchically ordered phases of
HDPE/PS/PMMA were generated with all phases fully continuous. It was shown that this
phenomenon was governed by the Harkins equation and is a thermodynamically driven process.
A positive spreading coefficient of PS over PMMA (λPS/PMMA) results in the PS phase locating at
the intersection of the HDPE and PMMA phases(Guo, Packirisamy, et al., 1997; Reignier &
Favis, 2000). Figure 5-2a illustrates this case where in a 40/20/40 HDPE/PS/PMMA blend,
PMMA phase is encapsulated by PS phase in the matrix of HDPE. By controlling the
concentration of the phases, a region is determined in which all phases are fully continuous. A
40/10/50 HDPE/PS/PMMA ternary blend is another example of this region where the
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