The inner pore structure of etched aluminum foil electrodes of aluminum electrolytic capacitors has been successfully visualized by a new resin-replica method using an Araldite epoxy resin as the packing material. The most interesting point of this resin-replica method is that both the packing material and porous samples can be evacuated so that the resin monomer can effectively fill the pores. This made it possible to reveal the fine structure of porous aluminum electrodes. Since this epoxy resin is stable to HCl, H2SO4, and HF, this resin-replica method is adoptable to visualize the pore structures of various substrates such as porous electrodes, catalysts, and adsorbents.
