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ELECTROCHEMISTRY 15

protection of metals from corrosive decay are among the many applications of
electrochemistry in metallurgy.
1.5.2.3. Engineering. Electrochemical engineering is the basis of a large
portion of the nonferrous metals industries, in particular, the production of aluminum
by deposition from a molten salt containing aluminum oxide. As noted earlier,
electrochemical energy converters, fuel cells, provide the on-board power for space
vehicles, and there are prospects of evolving from the thermal to the electrochemical
method of utilizing the energy of chemical reactions. One of the most important
applications is the prospect of clean, pollution-free electrical on-board power for
automobiles. Environmental issues, in general, as well as the real threat of global
warming from buildup, favor clean electrochemical processes.

1.5.2.4. Biology. Food is converted to energy by biochemical mechanisms
that have an efficiency much greater than that of some corresponding forms of energy
conversion involving the heat-engine principle. Such high efficiency in energy
conversion involves electrochemical reactions in the mitochondrion, a part of the
biological cell. Correspondingly, the transmission of impulses through nerves, as well
as the stability of blood and the functioning of many of the macromolecules involved
in biological processes, depends on aspects of electrochemistry that concern
electrochemical charge transport and the repulsion between bodies bearing the same
electrical charge. The formation of blood clots and the resulting heart attack are
influenced by the electrical charge on the arterial wall and that on the colloidal particles
in blood.
1.5.2.5. Geology. An example of electrochemistry in geology concerns
certain types of soil movements. The movement of earth under stress depends on its
viscosity as a slurry; that is, a viscous mixture of suspended solids in water with a
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consistency of very thick cream. Such mixtures of material exhibit thixotropy, which
depends on the interactions of the double layers between colloidal particles. These in
turn depend on the concentration of ions, which affects the field across the double layer
and causes the colloidal structures upon which the soil’s consistency depends to repel
each other and remain stable. Thus, in certain conditions the addition of ionic solutions
to soils may cause a radical increase in their tendency to flow.

1.5.3. Electrochemistry as an Interdisciplinary Field, Distinct from
Chemistry
All fields in chemistry (e.g., that of the liquid state or of reaction kinetics) are
connected to each other and, indeed, fields treated under chemistry tend, as time goes
on, to move toward the more sophisticated level attained in physics. Chemists
undertake approximate treatments of relatively complicated problems that are not yet

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Thus, certain soils, when appropriately agitated, suddenly become much less viscous and start to flow
easily, a dangerous thing if there is a house on top.