The use of polymerized high internal phase emulsions
(polyHIPEs)
as templates for electroless nickel plating is a promising method
for producing ultra-porous metallic lattice structures with consistent
wall thickness. These structures have desirable properties such as
low density, high specific strength, resilience, and absorbency, making
them suitable for various applications including battery electrodes,
catalyst supports, and acoustic or vibration damping. This study aimed
to optimize and investigate the electroless nickel plating process
on polyHIPEs. Initially, a surfactant (Hypermer)-stabilized water-in-oil
emulsion based on 2-ethylhexyl-acrylate and isobornyl-acrylate was
used as a 3D printing resin to create polyHIPE structures. Then, the
electroless nickel plating process was optimized using polyHIPE discs.
The study also examined the effects of air, argon, and reducing atmospheres
during the heating process to remove the polyHIPE template using metallized
3D-printed polyHIPE lattice structures. The findings indicated that
different atmospheres led to the formation of distinct compounds.
While nickel-coated polyHIPEs were fully oxidized in an air atmosphere,
nickel phosphide (Ni3P) structures occurred in argon and
reducing atmospheres along Ni metal. Moreover, in argon and reducing
atmospheres, the porous structure of the polyHIPEs was retained as
the internal structure was completely carbonized. Overall, the study
demonstrated that intricate polyHIPE structures can be used as templates
to create ultra-porous metal-based lattices for a wide range of applications.