Geoscientists resolve inconsistent data on crystal growth, dissolution
Virginia Tech Geoscientists Patricia Dove and Nizhou Han have demonstrated that crystals dissolve and grow by the same set of analogous ‘reversed’ mechanisms. Previously, the scientific community had long-maintained that growth and dissolution could not be unified into a single framework of understanding. The new evidence is certain to overturn that perception.
Dove and Han, faculty in Virginia Tech’s College of Science, and James J. De Yoreo of Lawrence Livermore National Laboratory report their research in the Oct. 17 - 21 on-line Early Edition of the Proceedings of the National Academy of Sciences (Mechanisms of classical crystal growth theory explain quartz and silicate dissolution behavior).
“We call this the Eureka paper,” said Dove. “For more than a decade, our group has been studying how minerals and crystals dissolve while also collaborating with Jim De Yoreo on how organisms grow crystals and minerals into complex shapes such as seashells and bone. It was because of the unique intersection of these two research areas in our laboratory that we were able to establish this fundamental link.”
One of the most convincing indications that this paper is onto something quite profound is that the researchers' approach reconciles inconsistencies between two pre-existing data sets on the dissolution rate of a completely different kind of crystal family (kaolinite), according to reviewer Bruce Watson, professor of geochemistry at Rensselaer Polytechnic Institute.
Kaolinite is an important earth and industrial material. The researchers show evidence for why their approach is likely to prove applicable to many different kinds of natural and manufactured crystals.
The essential idea is intuitive and elegant with profound implications for all disciplines where crystal dissolution is important, Watson wrote.
In addition to deep scientific questions regarding how fast minerals dissolve over geologic time, the findings will also give new insights for understanding such diverse questions as the long-term durability of containers that will hold nuclear waste, lifetimes of artificial bone materials, and possibly other biomedical issues, including drug delivery, Dove said.
"Dr. Dove's findings offer a good unifying approach for explaining crystal and mineral dissolution and growth," said James Mitchell, National Academy of Sciences member and professor emeritus of civil and environmental engineering at Virginia Tech. "It offers a new view that is consistent with the data. After you read it, you say, 'Why didn't I think of that.'" But it is an approach that classical geochemists have not used before, he said.
Dove and her research group won the Department of Energy Best University Research Award when she presented these findings at the symposium on "Isotope and Analytical Geochemistry" in June in Gaithersburg, Md. She is the only two-time winner of this Department of Energy recognition, having also received this award in 1999 at the "Interfacial Processes in Geosciences" symposium at Pacific Northwest National Lab in 1999.
Learn more about her work at: http://www.geos.vt.edu/people/user_detail.php?department_id=1&user_id=2.
