| Muck and Mystery Loitering With Intent |
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Now that we're mucking about with them, we've noticed that mother nature is a grand master.
Minerals have an enormous range of physical and chemical properties due to a wide range of composition and structure, including particle size. Each mineral has a set of specific physical and chemical properties. Nanominerals, however, have one critical difference: a range of physical and chemical properties, depending on their size and shape.They're everywhere. I was reading somewhere about natural quantum effects in living organisms. As we become more knowledgeable about very small and very fast things it seems that we are gaining a far deeper understanding of natural systems too. . . and they are even more complicated than we dreamed."This difference changes our view of the diversity and complexity of minerals, and how they influence Earth systems," said Michael Hochella of the Virginia Polytechnic Institute and State University in Blacksburg, Va.
The role of nanominerals is far-reaching, said Hochella. Nanominerals are widely distributed throughout the atmosphere, oceans, surface and underground waters, and soils, and in most living organisms, even within proteins.
Nanoparticles play an important role in the lives of ocean-dwelling phytoplankton, for example, which remove carbon dioxide from the atmosphere. Phytoplankton growth is limited by iron availability. Iron in the ocean is composed of nanocolloids, nanominerals, and mineral nanoparticles, supplied by rivers, glaciers and deposition from the atmosphere. Nanoscale reactions resulting in the formation of phytoplankton biominerals, such as calcium carbonate, are important influences on oceanic and global carbon cycling.
On land, nanometer-scale hematite catalyzes the oxidation of manganese, resulting in the rapid formation of minerals that absorb heavy metals in water and soils. The rate of oxidation is increased when nanoparticles are present.
Conversely, harmful heavy metals may disperse widely, courtesy of nanominerals. In research at the Clark Fork River Superfund Complex in Montana, Hochella discovered a nanomineral involved in the movement of lead, arsenic, copper, and zinc through hundred of miles of Clark River drainage basin.
Nanominerals can also move radioactive substances. Research at one of the most contaminated nuclear sites in the world, a nuclear waste reprocessing plant in Mayak, Russian, has shown that plutonium travels in local groundwater, carried by mineral nanoparticles.
In the atmosphere, mineral nanoparticles impact heating and cooling. Such particles act as water droplet growth centers, which lead to cloud formation. The size and density of droplets influences solar radiation and cloud longevity, which in turn influence average global temperatures.
"The biogeochemical and ecological impact of natural and synthetic nanomaterials is one of the fastest growing areas of research, with not only vital scientific, but also large environmental, economic, and political consequences," the authors conclude.
Update:
The essence of nanoscience is observing, measuring, and understanding the variations of properties and reactivities as a function of size and shape. Structural variations that respond to size change or surface area change may include expansion and contraction of bonds, changes in bond angles, and variations in population and distribution of vacancies and other defects such as steps, kinks, edges, and corners. In the smallest nanoparticles, this results in a redistribution of electronic structure that affects reaction characteristics with the outside world. Measurement of these aspects remains a great challenge and priority for future mineralogists, the authors note.