SCHOTT solutions no. 1/2014 > Otto Schott Research Award 2014
The Glass Laboratory inside a Mountain
Experimental research on volcanoes has been the main focus of the well-known researcher Professor Dr. Donald Dingwell’s work since the 1990s. The Canadian researcher was presented with the 2014 Otto Schott Research Award for his work.
Even back in the Stone Age, we humans used volcanic glass to produce cutting tools and spearheads. Donald Bruce Ding-well first met up with obsidian, which is rock formed by cooled lava, during his junior high school days in his home country of Canada when he discovered a photograph published in a school book on the geosciences. He certainly didn’t realize at the time that he would one day conduct research on the natural laboratories where volcanic glass is produced. He went on to study physics and chemistry with geology as an elective.
The researcher born in 1958 didn’t discover his passion for volcanology until he reached his thirties. Although volcanoes have accompanied us through history and evolution, they were studied in a rather one-sided manner from a modern science perspective. The current Professor of Experimental Volcanology and Director of the Department of Earth and Environmental Sciences at the LMU in Munich recalls that this was ”limited to a descriptive approach.” Researchers closely examined all of the deposits that eruptions had exposed and then attempted to draw conclusions as to the physical and chemical processes that went on inside the mountain. ”This type of field work is almost an art,” says Dingwell – and yet colleagues in the fields of physics and biology would have hardly referred to volcanology as a modern science due to the lack of the elements of simulation and experimentation. In the meantime, this has changed completely – the latter thanks mainly to Donald Dingwell and his work in the area of experimental volcanology.
But how can these types of volcanoes be simulated inside a laboratory? The ”artificial” volcanoes can be found in a basement room inside a university building in Munich. Tubes up to four meters in length and as wide as water buckets form the vents that transport the explosion to the surface. A furnace generates temperatures up to 1,300 degrees Celsius and rocks are heated up under pressure inside it. And just like a real volcano, it erupts when the pressure is suddenly allowed to escape. The team of researchers that works with Professor Dingwell measures how quickly the ejected particles, including glass, are propelled. And their size is determined by simply washing them off of the walls of the vents after the experiment is over. ”The glasses that this produces are snapshots of the structure of the liquids that simply never had the chance to cool down in a thermodynamic balance. This is a special state of nature that really fascinates me,” Dingwell explains.
At Dingwell's laboratory at the University of Munich, pressure is exerted on rocks at a temperature of 1,300 degrees Celsius and a volcanic eruption is simulated. Photo: SCHOTT/H.-J. Schulz
Dingwell and his colleagues had to overcome a number of obstacles in order for experimental volcanology to reach this point. In order to be able to determine the effects of hot liquids and their cooled down glass end products on a volcanic eruption, the researchers needed information on the exact properties of these substances. Their precise determination has made Dingwell what he is today for the world of glass: one of the most renowned experts on characterizing glass and glass melts.
People turn to him particularly when understanding glass calls for experiments to be performed under very special conditions or on extremely rare compositions. After all, borderline cases are the rule for the volcanologist. Volcanic glasses often contain extremely high shares of admixtures such as water and gases, for example, which change their properties in many different ways. ”We would have loved to be able to look up these topics in reference works, but couldn’t find many answers to even the most basic questions concerning the density, heat expansion coefficient, compressibility, surface tension or solubility of gases under high pressure,” Dingwell adds. Countless scientific publications document how thoroughly he and his colleagues have collected this data. The researchers determined the thermomechanical properties of silicate glasses and measured the water solubility in melts. Today, the articles they have published are required reading for all industrial researchers whose job is to purify glass, which means to drive out the water and soluble gases from the melt in order to prevent bubbles from forming in the final glass product. Several of the articles Dingwell’s working group has published have also dealt with the topic of how the composition of a glass affects viscosity and thermal expansion. They managed to significantly advance the understanding of viscoelastic reactions with simple and complex glasses. ”In the meantime, we now have the formulas we need in order to be able to derive the properties of a glass from its composition and structure,” Dingwell says. This is knowledge that also benefits the researchers who work in the laboratories in the glass industry and explains why Dingwell is now being honored with the Otto Schott Research Award valued at 25,000 euros, which is presented every two years.
Professor Donald Dingwell (2nd from left) was honored with the Otto Schott Research Award for his research on volcanic glasses. The award was presented by the Chairman of the Board of Trustees of the Ernst Abbe Fund and SCHOTT Board member Dr. Hans-Joachim Konz (2nd from right) at an international conference on glass held in Aachen, Germany, at the end of May. The picture also shows Board of Trustee members Professor Reinhard Conradt (RWTH Aachen; left) and Professor Carlo Pantano (Penn State University; right). Photo: SCHOTT/A. Sell
”Professor Dingwell is an outstanding researcher whose work on the thermomechanical properties of silicate glasses and melts has a major impact on the geosciences, glass science and glass technology,” emphasized Professor Carlo Pantano, a member of the Board of Trustees of the Research Award, at the award ceremony. ”These basic insights have also resulted in a better understanding of melting and shaping of industrial glasses,” he added. <
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