17:15 〜 19:15
[O08-P09] Morphological Change of Metal Dendrite by Addition of Surfactants: Analysis on Fractal Dimension, Branch Length and Branch Angle
★Invited Papers
キーワード：金属樹、樹枝状パターン、自己相似、界面活性剤
Branching patterns are widely observed in nature, from nervous systems to dendritic drainage patterns. These patterns have universal structures exhibiting self-similarity over various scales. When a voltage is applied to an electrolyte solution, metal dendrite patterns grow from a cathode to an anode at the air-liquid interface. Many studies have investigated macroscopic metal dendrite patterns on the 10 mm scale depending on various parameters. In metal electrodeposition, including metal dendrite, the introduction of specific additives leads to interface smoothing on the scale of approximately 10-2 mm to 10-1 mm. For example, surfactants, quaternary ammonium salts, and polymers are known to lead to these effects.
In this study, we investigated how interface smoothing at a 10-1 mm scale affects branching patterns on a much larger scale of roughly 10 mm (about 102 times larger). We made an experiment with zinc dendrites as a model system to investigate the effects of growth surface smoothing on large-scale dendrite patterns. Because the surfactants of the Pluronic family were reported to smoothen the electrodeposition growth interface, we added Pluronic F-127 to the zinc electrolyte solution. We examined not only the fractal dimension, which has been traditionally studied, but also quantities that characterize the shape of the pattern, such as the distribution of branch lengths and branching angles.
The results show that the addition of Pluronic F-127 made dendrite patterns sparse and produced the patterns with low fractal dimensions. Increasing the surfactant concentration enhanced the appearance of long branches, while the branching angles were not much affected.
In this study, we investigated how interface smoothing at a 10-1 mm scale affects branching patterns on a much larger scale of roughly 10 mm (about 102 times larger). We made an experiment with zinc dendrites as a model system to investigate the effects of growth surface smoothing on large-scale dendrite patterns. Because the surfactants of the Pluronic family were reported to smoothen the electrodeposition growth interface, we added Pluronic F-127 to the zinc electrolyte solution. We examined not only the fractal dimension, which has been traditionally studied, but also quantities that characterize the shape of the pattern, such as the distribution of branch lengths and branching angles.
The results show that the addition of Pluronic F-127 made dendrite patterns sparse and produced the patterns with low fractal dimensions. Increasing the surfactant concentration enhanced the appearance of long branches, while the branching angles were not much affected.