Cw. Kim et al., MECHANISM OF THE MERCURY BEATING HEART - AN EXPERIMENTAL-STUDY OF THEELECTROCHEMICAL-MECHANICAL OSCILLATOR, Electrochimica acta, 41(18), 1996, pp. 2829-2836
Detailed mechanism of oscillation of the ''mercury beating heart'' was
investigated for the iron-triggered and the aluminium-triggered cases
by probing the electrode potential, electrocapillarity and the shape
of the mercury surface. Electrochemical reductions primarily of dissol
ved oxygen on the mercury surface and corrosion reactions of the activ
e metals such as Fe or Al drove the potential of mercury alternately u
p and down. The range of potential oscillation was found to be on the
positive side of the electrocapillary maximum of mercury in the case o
f Fe-triggered oscillation in acidic solutions, and on the negative si
de in the case of Al-triggered oscillation in basic solutions. The ult
imate cause of the mercury oscillation was shown to be fluctuating sur
face charge density without involving a film-formation on the mercury
surface or oxidation of mercury, at variance with some views in the li
terature. Copyright (C) 1996 Elsevier Science Ltd