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Download fileCoalescence of a Water Drop with an Air–Liquid Interface: Electric Current Generation and Critical Micelle Concentration (CMC) Sensing Application
journal contribution
posted on 2019-04-01, 00:00 authored by Yongxin Song, Bin Xu, Yapeng Yuan, Hao Xu, Dongqing LiA phenomenon
that electric current is generated when a pendant
water droplet touches an air–electrolyte solution interface
is investigated in this paper. A measurement system developed in this
study consists of a hollow electrode for droplet generation, a counter
electrode immersed in an electrolyte solution, and an electrometer
with high precision. Once a droplet touches the air–electrolyte
solution interface, it will be pulled into the electrolyte solution
and an electric current is produced during this process. Experiments
showed that the magnitude of the electric current depends only on
the pendant droplet and has nothing to do with the types of the electrolyte
solution (with a much larger volume than that of the droplet) below
the drop. The electric current is generated by the electric potential
difference between the droplet and air–electrolyte solution
interface and the liquid bridge formed during droplet coalescence.
As a result, the magnitude of the generated electrical current mainly
depends on the size, pH, and the type of the solution forming the
droplet. Determining the critical micelle concentration using this
system was successfully achieved to show the powerfulness of this
system.