The substrates were then immersed in a Pd electroless
plating (ELP) solution, at 60 C, in order to deposit metallic Pd
layers onto the activated surface.
The Pd ELP solution was prepared according to the composition presented in Table 1
and left to stabilize for 16 h before being used .
The volume of Pd ELP solution was fixed at 3.5 mL per cm2 of substrate
surface area, as suggested by Mardilovich et al.
The ELP procedure was performed either once or twice, with a plating
time of 60min per cycle, resulting in Pd membrane of different
thicknesses.