Pore structure characterization and in-situ diffusion test in nanoporous membrane using SANS

Using a selective phase dissolution technique, nano-porous membrane can be produced from simple two-phase metallic alloys. It contains through-thickness elongated channel-like pores of only a few hundred nanometer width and has a number of prospective applications. Knowledge of microstructural parameters is essential for membrane optimization. Non-destructive characterisation of the pore microstructure was carried out by small-angle neutron scattering technique. The combined results from pinhole and double-crystal facilities enabled to determine microstructural parameters of the nanoporous membrane (pore-to-pore distance, raft thickness, pore volume fraction, specific interface). The contrast variation using D₂O and H₂O helped to conclude on scattering length density of both γ' pore walls as well as the original γ-phase matrix. The kinetics experiment showed that the pores are filled instantly by liquid. The subsequent emptying of pores by evaporation was observed.