121st General Meeting of the KCS

Type Poster Presentation
Area Electrochemistry
Room No. Event Hall
Time 4월 20일 (금요일) 11:00~12:30
Code ELEC.P-568
Subject In situ Confocal Microscopic Observation of Electrochemical formation and Collision of Emulsion Droplets
Authors Sangmee Park, TAEK DONG CHUNG1,*
Program in Nano Science and Technology, Seoul National University, Korea
1Division of Chemistry, Seoul National University, Korea
Abstract 1-ethyl-1-methylpyrrolidinium bromide (MEPBr) is a promising bromine-complexing agent that forms insoluble organic phase of MEPBr3 in redox flow battery. A series of optical images obtained by real time confocal microscopy with tens of millisecond interval visualize how MEPBr3 emulsion is electrochemically formed and collide with the electrode surface. Two types of electrodes, a Pt microdisk of 10 μm diameter and a 2.5 mm long Pt wire of 25 μm diameter, show evident correlation between electrochemical behaviors and optical images of droplets. The droplets start generating on the electrode surface at the onset potential for bromide oxidation. As the overpotential increases, the droplets adsorbed onto the electrode surface become larger and small droplets start detaching at 0.925 V or higher potential. Some of the droplets fallen away from the surface move back and collide with the electrode surface. At this time spike shaped current is observed by chronoamperogram simultaneously. In this study, real time confocal microscopy reveals that the droplets are heterogeneously formed by electrochemical reaction and single droplet collide back onto the electrode surface, providing a better understanding of the phenomena of bromide redox flow battery electrode surfaces.
E-mail psm71500@naver.com