Dynamics of single hydrogen bubbles at Pt microelectrodes in microgravity

The dynamics of single hydrogen bubbles electrogenerated in acidic electrolytes at a Pt microelectrode under potentiostatic conditions is investigated in microgravity during parabolic flights. Three bubble evolution scenarios have been identified depending on the electric potential applied and the acid concentration. The dominant scenario, characterized by lateral detachment of the grown bubble, is studied in detail. For that purpose, the evolution of the bubble radius, electric current and bubble trajectories, as well as the bubble lifetime are comprehensively addressed for different potentials and electrolyte concentrations. We focus particularly on analyzing bubble-bubble coalescence events which are responsible for reversals of the direction of bubble motion. Finally, as parabolic flights also permit hypergravity conditions, a detailed comparison of the characteristic bubble phenomena at various levels of gravity is drawn.

Automated summary

The dynamics of single hydrogen bubbles electrogenerated in acidic electrolytes at a Pt microelectrode under potentiostatic conditions in microgravity during parabolic flights were investigated. Three bubble evolution scenarios were identified, with a focus on the dominant scenario characterized by lateral detachment of grown bubbles. Comprehensive analysis was conducted on the evolution of bubble radius, electric current, bubble trajectories, and lifetime for different potentials and electrolyte concentrations, as well as bubble-bubble coalescence events. A detailed comparison of characteristic bubble phenomena at various levels of gravity was also explored, including hypergravity conditions permitted during parabolic flights.