Application of Videomicroscopy to In Situ Studies of Electrodeposition

Abstract

not Available.

Micro-scale mass-transfer variations during electrodeposition

“…She combined a long-range microscope objective on a traveling stage with a video camera/cassette-recorder to record the growth of zinc nodules. The resolution achieved was about 1 I.tm [31]. McVay showed that nodules coalesce and elongate both downstream and upstream, though predominantly in the former direction [30].…”

“…When the nodules reach a critical size, approximately 20 um in height, they begin to elongate in the direction of flow, as shown by McVay [31] and Jaksic [22][23][24].…”

“…McVay [30,31] was the first to successfully observe the emergence of striae in situ. She combined a long-range microscope objective on a traveling stage with a video camera/cassette-recorder to record the growth of zinc nodules.…”

“…Because of centrifugal forces, bubbles congregate at the electrode surface and interfere with and obscure the deposition process. To study whether striae occur in the absence of significant hydrogen evolution, McVay [31] deposited zinc at conditions of high current efficiency (98% +) in an in-situ flow cell. Her time-lapse video of the deposition process shows that nodules elongate and line-up without the presence of any macroscopic flow disturbance or hydrogen bubbles upstream of the nodules themselves.…”

“…In the case of primary current distribution solved numerically by Prentice and Tobias [31], once the ratio of amplitude to wavelength of a sinusoidal profile exceeds 0.15, the valley region has a greatly diminished current density. This numerical result may also be used to estimate the distance at which the potential lines become parallel to the average surface plane, and the current distribution becomes uniform.…”