The growth of particles via self-assembly process may give rise to various morphologies. The selection of silver dendrite for investigation provides not only an example but also a practical need. The self-assembly of atoms on a high surface energy zig-zag atom plane contributes to the formation of a dendrite arm with a high aspect ratio. The findings of this study also reveal the existence of an atomic plane with a level of d-spacing zig-zag kink step on the dendrite tip. We report here for the first time the aggregation of atoms to form nano embryos and thereafter the sequential formation up to dendrite using HRTEM (High Resolution Transmission Electron Microscopy). High aspect ratio morphology is indicative that the growth rate of dendrite is much faster in the longitudinal direction than in the circular radial direction of the dendrite arm. However, there has been little discussion of the origin of dendrite formation and the directional growth behavior of a dendrite arm with a high aspect ratio. These previous studies mostly focused on discussing the morphology of dendrite, including the hexagonal dendrite head and the slanted structure. The aggregation and coalescence of nano particles may occur via oriented attachment 19 and may lead to attachment to the dendrite tip, which accelerates dendrite growth 20, 21, 22.Īs mentioned above, numerous studies have discussed the growth behavior of fractal dendrite. The growth mechanism of silver dendrite, with a final hexagonal dendrite head 7, 18, has been attributed to oriented attachment 6, 7. At a longer reaction time, the relaxation of small grains occurs, which gives rise to a hexagonal plate head. At a short reaction time, the concentration gradient dominates the growth and thus controls kinetic factors. The morphology of silver dendrite is governed by the competition between thermodynamic and kinetic factors 17. The dendrite shape of electrodeposited silver structures has been determined based on deviations from equilibrium 16. The secondary dendrite arm can grow vertically or slanted at around a 60° angle relative to the primary dendrite stem (Fig. Each portion of the dendrite structure is single crystal in nature 14, as also revealed in the TEM image (Fig. The fractal dendrite growth induced by electrochemical migration has been simulated and analyzed 13. The methods available for producing silver dendrite include replacement reactions 6, electrochemical 7, 8, 9, solvothermal 10, oxidation reduction 4, wet chemical 11, and template reduction 12 methods, etc.ĭendrites generally grow from a primary dendrite stem to secondary dendrite and tertiary dendrite arms. Silver dendrite also exhibits better sintering and percolation performance in electric conductive composites than silver flakes 4. Silver dendrite has been found in various applications in sensors 1, catalysis 2, surface enhanced Raman scattering 3, and electronics 4, 5, among others.
0 kommentar(er)
