a) b - École Polytechnique de Montréal

5.3.6 Layer-by-Layer Deposition
The solid substrate was alternatively immersed for 25min in PSS and PANI solutions with
intermediate water rinsing. An aqueous PSS solution of 10 mg/mL buffered to a pH of 2.5 was
used as the negative polyelectrolyte solution. The PANI solution was prepared using a procedure
by Cheung et al.(Cheung, et al., 1997). A water bath with a pH adjusted to 2.5 was used to
remove excess PSS and PANI on the surface of substrate after each dipping. The process was
periodically interrupted and samples were dried first under a gentle flow air and then by putting
samples in the vacuum oven for 30min prior to weighing.
5.3.7 Filling the Porous Sample with a Resin
A two-component epoxy(Epofix) was used to impregnate the pores of the porous substrates.
Epofix resin and Epofix hardener were mixed and stirred carefully for at least 2 minutes by
maintaining a mixing ratio of 15 to 2 parts by volume. The mixture was carefully poured into the
mould. To eliminate air bubbling during the hardening, the Epovac vacuum impregnation unit
was operated for 24h. After evacuating the specimen chamber, the impregnating fluid is then
introduced into the chamber under atmospheric pressure by means of a disposable plastic tube.
5.3.8 Characterization and Phase Morphology
5.3.8.1 Microtomy and Scanning Electron Microscopy
Samples were cut and microtomed using a Leica-Jung RM 2065 equipped with a glass knife and
a cryochamber type (LN 21). Other samples were fractured under liquid nitrogen known as
cryofracture method. After chemical extraction with dimethylformamide to remove all
components except HDPE, a JEOL JSM 840 scanning electron microscope was employed to
observe the morphology of the samples. Photomicrographs were taken at a range of 5-12keV
after coating the surface of the sample with a gold/palladium alloy by plasma deposition.
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