Science Floats Glass To Gain New Insight

Scientists at the Oak Ridge National Laboratory in Oak Ridge, TN are hoping to gain a greater insight into the nature of glass using a new $1.65 million Neutron Electrostatic Levitation Chamber (NESL). Using the NESL, scientists are hoping to float liquids and study them, unmixed with the environment, in order to understand glass. It sounds somewhat trite, but this is actually a really interesting experiment. Glass is not so much a product or item as it is a state of being--it's a part of the solid, gas, liquid set. Team leader and physicist Kenneth Kelton explains,

We've used glasses since 4,000 years ago in Mesopotamia, but we still don’t understand the process – how it goes from a liquid to a glass. It's one of the most interesting dynamical processes anywhere around. If we look at the difference in structure from a liquid to a glass, we can see a difference, but it's very subtle. The question is, What's different?

In order to figure out what makes glass different from liquid, Kelton and his team are going to float liquid forms of several materials, such as titanium, zirconium, nickel, platinum and their alloys. Hopefully in time, we will see some solid results from the study!

Georgia Tech Researchers Discovery Mystery Ceramic

Researchers at Georgia Tech have created a new ceramic material that could have revolutionary applications in fuel cell technology. It is still in a nascent, developmental stage, but it could reduce tremendously the cost of creating fuel cells. The high cost of fuel cells has been a barrier to their wider adoption.

The Georgia Tech researchers were supported by the U.S. Department of Energy’s Basic Energy Science Catalysis Science Program. Using the government money, they developed a new material for use in solid oxide fuel cells (SOFC). A SOFC generally uses a ceramic electrolyte, which in this case is a yttria-stabilized zirconia (YSZ) ceramic. Traditionally, YSZ operates poorly in an SOFC because it is inefficient, clogs easily, and must operate at a high temperature due to its poor conductivity at low temperatures. The new ceramic material, though, gets around all these drawbacks.

The material is a Barium-Zirconium-Cerium-Yttrium-Ytterbium Oxide (BZCYYb), which can be used as a coating on a traditional anode or a replacement for YSZ altogether. It has been lab-proven for performance up to 1,000 hours of continuous use, but it requires more testing to determine its stability and lifespan.

Researcher Meilin Liu says,

“Solid oxide fuel cells offer high energy efficiency, the potential for direct utilization of all types of fuels including renewable biofuels, and the possibility of lower costs since they do not use any precious metals... We are working to reduce the cost of solid oxide fuel cells to make them viable in many new applications, and this new material brings us much closer to doing that.”

Zirconium: Not Just For Rings and Things

If you’ve ever watched a shop at home television channel or been in the market for inexpensive jewelry, then you’re probably familiar with cubic zirconia, the synthetic alternative to diamonds. According to Wikipedia, cubic zirconia has been the most “economically important competitor for diamonds since 1976.” More generally, though, zirconium is a chemical element (Zr) that is found in nature within the earth’s crust and sea water. Its applications are much wider-ranging than jewelry.

Zirconium’s global usage shows that it is predominantly used within the field of technical ceramics. For instance, 54% of China’s zirconium consumption goes towards ceramics. Zirconium is extremely hard, stable, and dense. It is overwhelmingly strong. Its fine grain size makes it perfect for creating sharp blades. Ceramic knives are one of the latest crazes in kitchenwares, for instance. In addition to sharpness, zirconium can be used to create porous ceramic filters and diffusers for washing and spraying functions. Its durability, density, and corrosion resistance allows it to be used in applications that require dealing with acids.

I stumbled across this page, which gives a lengthy overview of zirconium, from its global availability and application to end users and producers.

Zircon consumption, like that of most other commodities, has been hit by the global economic slowdown. However, supply (both existing and potential), too, appears to have been impacted equally, if not more, severely. Not only have a number of suppliers in both Africa and Australia (for example, Australian Zircon NL (Bloomberg Ticker—AZC:AU)) been facing financial challenges, with consequent decreases in production, but other producing countries have also been facing limitations on production. Indonesia, in particular, saw zircon production fall more than 40% in 2008 from the level in 2007.

In addition, Refractron has an excellent page about a special kind of zirconium, Yttria Tetragonal Zirconia Polycrystal (Y-TZP).

Y-TZP has a material density of greater than 6.0 g/cc, a maximum operating temperature of 2000 C. This material has the highest flexural strength of the zirconia materials particularly when processed using a HIP (Hot Isostat Press). Values are 900 MPa and 1400 MPa (HIP'd). The hardness is 13-13.5 GPa, Fracture Toughness is 8.0 MPa-m1/2 and Thermal expansion (C.T.E.) is 10.2 x E6/ degree C).

So the next time you’re up late and watching QVC shilling cubic zirconium rings, remember that what you’re actually seeing is a product related to technical ceramics.