Environmental Engineering Reference
In-Depth Information
Fig. 1.2 The main stages of the transformation of metal atoms into a bulk metal
atmosphere changes in successive stages, under the influence of random environ-
mental factors, until they agglomerate, become sedimentable and no longer react
with these factors.
This process can take years, because many metal ions, having changed their
chemical composition, become colloidal, through coordination with water mole-
cules, and acquire an electric charge. As a result, coalescence with particles of the
same type is possible only after the random destabilisation of the system in an
electric field or through colloidal ageing.
At least partially, the theory exposed briefly above is also valid for very large
molecules or organic macromolecules, because they can float in the atmosphere due
to Brownian forces or the forces that move the air and react with its components,
among themselves or with inorganic particles, changing their nature and state of
matter.
The nanoparticle-size elements of the living kingdom are at the border between
chemistry and biology (cholesterol, haemoglobin, hemocyanin, chlorophyll, etc.),
as they are part of the life cycle, although most of them can be synthesised as well.
Similar in size to the largest nanoparticles, viruses are the simplest forms
capable of reproduction. However, if one considers the primary composition
(mainly carbon, nitrogen and oxygen) of these representatives of the living king-
dom, the changes they undergo follow both the food chain and the sequence of
perpetual change in the physical and chemical characteristics of matter.
Acknowledgements This work was supported by a grant of the Romanian National Authority for
Scientific Research, CNCS—UEFISCDI, project number PN-II-ID-PCE-2011-3-0762.
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