ONLINE EXTRA: Advancing Ceramic & Glass Technology

This year, the focus is on technical advances at two American universities and one U.S. Department of Energy research laboratory.

Ceramic Industry’s annual R&D Spotlight details three technical advancements in the ceramic and glass industries: a series of projects designed to improve the thermal performance of brick masonry; a process that converts titanium and its alloys to titania nanostructures through oxidation; and the implementation of glass and ceramics to improve the structural properties and energy efficiency of fuel cells.

Improving the Thermal Performance of Brick Masonry

The National Brick Research Center (NBRC) at Clemson University is working on a series of projects to improve the thermal performance of brick masonry. Brick masonry has traditionally been used as an extremely durable exterior cladding, but these materials have the potential for much higher levels of performance. In this work, the physical design of the brick has been optimized to both reduce the amount of raw materials needed to make a unit and the amount of fuel required to fire a unit. This optimization was achieved with finite element thermal simulations of the firing process and heat flow through the fired units.

The optimized designs also offer the potential to include insulation or phase change materials into the voids in the masonry to further reduce heat flow. Phase change materials, which are selected based on the fusion temperature and the magnitude of the latent heat of fusion, can be used to store heat during the hottest part of the day, which reduces the energy required to cool the structure. Test panels using optimized brick designs with various core-filling configurations have been constructed for testing in an environmental chamber to assess the effectiveness of these materials at reducing and managing heat flow. Thermal simulations of panels containing both insulation and phase change materials are also underway.

Based on the results of this work thus far, the NBRC predicts it will be possible to build more thermally efficient structures that utilize fewer raw materials, require less energy to produce and have the potential to last for hundreds of years.

For more information on this project and other work done by the NBRC, visit www.brickandtile.org.

Titania Nanostructures on Ti and Ti Alloys

The promise of technologies enhanced by the incorporation of nanostructures is as prevalent today as it has ever been. A major obstacle standing in the way of the realization of these technologies is the scaling of the techniques used to produce nanostructured materials to mass production. The Ohio State University’s Materials Science and Engineering Department has developed and is working to implement in several applications a process by which titanium and its alloys are converted to titania nanostructures by a simple oxidation process. These nanostucrtures could then be used to enhance bioadhesion on biomedical implants, light absorption and charge separation in solar cells for increased efficiency, and adsorption of gas molecules to increase sensitivity in molecular gas sensors. The technique is described as low-cost, highly scalable and effective on a wide range of Ti alloys.

For more information, contact Ben Dinan at Dinan.11@osu.edu.

Glass/Ceramic Technologies for Fuel Cells

As American demand for energy increases, laboratories across the country continue to push toward non-oil energy sources and solutions. Researchers at Pacific Northwest National Laboratory (PNNL) have developed new methods that incorporate glass and ceramics in emerging fuel cell technology to improve their structural properties and, consequently, increase their energy efficiency.

Fuel cells are electrochemical energy conversion devices that convert hydrogen and oxygen into water, which ultimately produces electricity. Traditional batteries store a limited amount of chemicals, and, once this reserve is consumed through the process of creating electricity, the battery is rendered useless. Fuel cells, on the other hand, offer a constant flow of chemicals and an unlimited lifetime.

The hermetic sealing of metal and/or ceramic components is a critical step in the fabrication of a solid oxide fuel cell (SOFC) stack. Researchers at PNNL have developed two unique methods that result in strong seals that can stand the test of time. The patented glass-ceramic seal technology possesses high resistivity and holds up well in both reducing and oxidizing environments. This technology can be tailored to yield a range of coefficients of thermal expansion (CTEs); furthermore, the sealant material exhibits strong bonding properties to both zirconia and ceria-based ceramic, with little or no interaction after thousands of hours of operation at elevated temperature. This new technology can be applied to the joining and sealing of tubular and planar ceramic SOFCs, oxygen generators, and electrolyzers, as well as membrane reactors for the production of syngas, commodity chemicals, and other products.

PNNL has also developed the glass fiber mesh method of joining, a technology that uses microscopic metal screening spots welded to metal surfaces that serve as anchors for heated glass. Ceramic fibers applied between the surfaces provide an insulating feature that allows stacks to withstand heating variations that commonly create seal failures in fuel cells. This patent-pending method is ideal for stainless steel-to-ceramic applications that require rapid heating and/or cooling (responsiveness), such as transportation and stationary applications like back-up distributed power generation.

For more information, call (509) 375-2489 or e-mail Bob Silva at robert.silva@pnl.gov.

Editor’s Note: This article was compiled from information submitted by laboratories and universities, and it is not intended to be a comprehensive overview of all ceramic and glass research currently in progress.