Various metallic structures of complex shape resembling living plant organisms (biomimetics) are produced as a result of self-assembly of nanowires growing on porous membranes in the course of pulse current electrodeposition. These structures occur if the electroplating is continued after the nanowires appear on the membrane surface. By varying the membrane geometry, pulse current electroplating parameters, and alternating electrodeposition from two baths composed of a variety of electrolytes, diverse models were fabricated, including a hollow container with a wall thickness of 10 nm -20 nm. This biomimetic method suggests an analogy between the shape-forming processes of plants and their metallic models. Nanostructured mesostructures of various metals (Ag, Pd, Ni), alloys (PdNi, PbIn) and hybrid structures (PdNi/Pb, PdNi/PbIn) were obtained. They can be of interest for fundamental research (self-assembly, morphogenesis) as well as for applications in nanotechnology (catalysis, nanoplasmonics, medicine, superhydrophobic surfaces).

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Key words: self-organization of Pd-Ni nanowires, consisting of nanocrystallites in amorphous matrix; architecture of mesoscopic 3D-structures, composed of nanowires. AbstractThe architecture of novel metallic mesostructures obtained via self-organization of growing nanowires has been investigated. Seashell-, fungus-and lotus leaf-shaped structures are reproducibly formed by programmable pulse current electrodeposition on porous membranes. The samples several millimeters in size are obtained. SEM investigation has revealed that the frame of the metallic "seashell" presents a hierarchical system with elements of fractal self-similarity at the nano-and micro-levels. The frame is a volumetric multilayer net with conical bundles of nanowires as building blocks. The Pd-Ni nanowires have V-like branches and periodic bulges ("beads"). TEM study showed that the nanowires consist of nanocrystallites dispersed in an amorphous matrix. Their sizes range from 4 to 15 nm. Local inhomogeneity of Pd-Ni solid solution was observed. In perspective, the proposed technique can be used as a 3D printer for the purposeful synthesis of novel materials with complex quantum nano-architecture.2

One challenge for advancing solid oxide fuel cell (SOFC) technology is to develop interconnect materials with adequate conductivity and stability for efficient long-term use. Proposed here is a technology for effectively modifying the surface of SOFC current collectors and significantly reducing the oxidation rate of ferritic stainless steel at elevated temperatures and high current densities. The formation of "Kirkendall voids" at the Crofer 22 APU ferritic stainless steel-intermetallic compound interface was observed and investigated. The Kirkendall voids play the role of a barrier layer blocking Cr diffusion to the surface and suppressing the formation of the resistive Cr2O3 surface layer. Long-term test measurements showed that the ASR value of the current collector-LSM junction decreases two times during the first 3000 hours and subsequently remains constant.