My colleague and pal, Megan Bricker, who is ACerS director of marketing and membership, looked up a few things to do while in Chicago. We’ll know where to look if we cannot find her!:

It’s time to make travel arrangements to Chicago for the 4^th International Congress on Ceramics with the 3rd Ceramic Leadership Summit Track. Not only is this conference providing first-class speakers on ceramic and glass issues that are shaping the future of ceramics, but it also is being held in one of the United States’ most popular cities—Chicago.

With its world-renowned museums, parks, shopping, architecture, music and food, Chicago is one destination city you won’t want to miss. Set on the beautiful waters of Lake Michigan, this city offers visitors of all ages plenty to see and do.

And, no one knows Chicago better than those who live there. ACerS member Jorge Ayala of Superior Graphite, Co. lives and works in Chicago. He says it’s simply an amazing city:

“One of my favorite things to do is to take a walk in Millennium Park. The view of the lake is spectacular. And, if you are in Millennium Park, you will be close to the Art Institute of Chicago and the Field Museum. Both are fabulous for visitors of all ages,” said Ayala.

In fact, the ICC4 conference’s closing banquet will be held in the stunning, new modern wing of the Art Institute of Chicago for all attendees and companion registrants.

If you are in the mood for shopping, look no further than Chicago’s famous Michigan Avenue, otherwise known as the “Magnificent Mile.” Chicago is home to more than 400 fashion designers and Michigan Avenue is lined with name brand shops and small whimsical boutiques.

While you are out shopping, take a good look around. You will see why visitors from all over the world come to see the birthplace of modern buildings and are in awe of Chicago’s cityscapes and architectural marvels.

If traveling with children, (and for “kids” of all ages”) I would personally recommend a stop at the Navy Pier to go to Chicago’s Children’s Museum where kids can explore three floors of fun and interactive learning. While there, I also wouldn’t miss the Smith Museum of Stained Glass, which is FREE to all visitors. A perfect night for me would end with delicious Chicago style deep-dish pizza and a drink at one of the amazing blues or jazz clubs.

If discovering the city on your own isn’t for you, then sign-up for one of the conference’s optional tours, one of which is to nearby Argonne National Laboratory.

There is so much to see and do in Chicago, you just might want to pack some extra clothes and stay a few more days. You’ll be glad you did.

As a native Chicagoan myself (even though it’s been a few … decades), here are a few of my favorite destinations not mentioned above:

• The Mueum of Science and Industry, with featured special exhibition, “MythBusters: The Explosive Exhibition.
• Wrigley Field, home of the Chicago Cubs (faith endures—maybe this is their year!).
• Berghoff’s, a downtown Chicago lunchtime institution and a uniquely Chicago experience.
• Willis Tower, test your faith in the strength glass in the “birdcage” observation decks.

Share

The efficiency of LED devices is limited by carbon point defects in the aluminum nitride transparency layer, which absorb useful wavelengths of light (around 4.7 eV). North Carolina State University researchers used computational methods and detailed experiments to make the discovery. Credit: Doug Irving; NC State.

The Materials Genome Initiative is shining the spotlight on modeling, simulation and computational methods for materials science, mostly for materials development.

Computational methods can be used to solve old problems, too, as a recent paper published by a group out of North Carolina State University demonstrates.

The 30-year old problem relates to absorption of ultraviolet light by single crystal aluminum nitride, a semiconductor that is used as a substrate for AlGaN-based UV emitting LEDs and laser diodes. Because these devices emit UV, they could be used to kill pathogens, for example, in drinking water or on surgical instruments. In a university press release, lead author Ramón Callazo says, “UV treatment utilizing LEDs would be more cost-effective, energy efficient and longer lasting.” Callazo is an assistant professor of MSE at NC State.

However, taking advantage of the UV-emitting property has been difficult because the substrates themselves absorb a fair amount of the UV.

Using density functional theory calculations, a research team at NC State determined that trace amounts of carbon were the culprit and that, according to the abstract, “substitutional carbon on the nitrogen site introduces absorption at this energy.” The team followed up by characterizing a series of single crystal wafers and showed that the absorption band increased linearly with increased carbon.

In a press release, coauthor Zlatko Sitar, professor of MSE at NC State, says,” Once we identified the problem, it was relatively easy and inexpensive to address.” HexaTech Inc., a university spin-off company that specializes in growing single crystal aluminum nitride, is already working on incorporating the research into its technology.

Of the 30-year old problem, Doug Irving, also a coauthor and department assistant professor, says in the press release, “we were able to solve it by integrating advanced computation, material synthesis and characterization. I think we’ll see more work in this vein as the Materials Genome Initiative moves forward, and that this approach will accelerate the development of new materials and related technologies.”

The paper is, “On the origin of the 265 nm absorption band in AlN bulk crystals,” is published online in Applied Physics Letters, http://dx.doi.org/10.1063/1.4717623.

Share

St. Edward Parish on the northwest side of Chicago has been a cornerstone of the neighborhood’s faith, social and cultural life since its founding in 1889. Credit: St. Edward Parish; www.stedward-chicago.com.

I grew up in a fairly homogeneous Irish-Polish neighborhood of Chicago, and most of my young life revolved around St. Edward Parish. The only foreigners I recall knowing were my friends’ grandmothers and grandfathers. (My own immigrant grandparents lived in a different city.)

Since then I have had the good fortune to know many foreign-born people, and when overseas, I have been the foreign-born person. In professions like ours, international and cross-cultural collaboration is common and even necessary. These collaborations seem to work very well, which is a testament to the ability of the parties involved to be unimpeded by cultural barriers.

The culture in which we are raised forms us and gives us a common framework for relating to society, often in subtle ways. Recent work by cognitive scientist, Rafael Nuñez of the University of California, San Diego, demonstrated this in the context of how time is conceptualized and communicated. A short news item in the April 27 Science issue provides some explanation.

In Western culture, we think of the future as “ahead” and the past as “behind.” Nuñez studied an Andean highlands people known as the Aymara, and found that they think of the future as unseen, and, therefore, it must be “behind,” and they gesture accordingly behind themselves to talk about the future. The past, however, has been seen, and is, therefore, out in “front.”

Later he studied the Yupno people from a remote valley region of Papua New Guinea and found that they think of time topographically, and the future is always represented by an “uphill” gesture and the past by a “downhill” one, regardless of which way the speaker is facing. The Science article says his interpretation is that these “different abstractions of time, including gestures, indicate the importance of the cultural aspects of language evolution.”

Language gives form and scope to the way we think about and conceptualize our world. Nuñez’s findings are a good reminder that we all carry our culture’s formative framework with us and that we may approach concepts from different points of reference.

Share

New papers that have been accepted for publication in the Journal of the American Ceramic Society are posted to “Early View” on the Wiley website and can be read even before the issue is printed. Below are summaries of selected papers currently available via Early View.

All members of The American Ceramic Society receive free online access to JACerS. To access any of the ACerS journals, or to become a member, visit www.ceramics.org.

Structural models of mullite phases including sillimanite and ι-Al2O3. Credit: JACerS; Wiley.

Mechanical Properties and Electronic Structure of Mullite Phases Using First-Principles Modeling

Sitaram Aryal, Paul Rulis and Wai-Yim ChingIn

This Feature Article, Aryal, Rulis and Ching from the University of Missouri-Kansas City describe a systematic and detailed theoretical investigation of the structures and properties of the phases in the aluminosilicate series Al_4+2xSi_2-2xO_10-x, where x is 0 to 1. They constructed many stoichiometric supercell models for the four well-known mullite phases in the series (3Al₂O₃∙3SiO₂, 2Al₂O₃∙SiO₂, 4Al₂O₃∙SiO₂ and 9Al₂O₃∙SiO₂) using experimentally reported crystal structures and systematic removal of selected atoms at the partially occupied sites to maintain charge neutrality. Aryal, Rulis and Ching then studied the electronic structure and mechanical properties of the series (as well as sillimanite, where x = 0, and silica-free τ-Al₂O₃, where x = 1) using first-principles calculations. They suggest that the first-principles results explain the experimentally observed structure and properties of mullite phases and their trends with x at the fundamental level.

SEM images of (a) G4 and (b) G6 with the EDS results at the indicated points. Credit: JACerS; Wiley.

Sn-Based Chalcogenide Composite as a High-Capacity Anode Materialfor Lithium Rechargeable Batteries

Youngmin Lee, Suk-Rok Bae, Bong Je Park, Dong Wook Shin, Woon Jin Chung and Yong-Mook Kang

This team of researchers in Korea synthesized high-capacity anode materials from tin-based chalcogenide composites. The team reports that the tin-germanium-sulfur matrix suppresses the volume expansion that can result from alloying between tin and lithium as well as the grain growth associated with the low melting temperature of the tin.

SEM secondary electron micrographs of surface of La2Ni0.9Cu0.1O4+δ sintered at (a) 1350°C and (b) 1450°C for 3 h. Credit: JACerS; Wiley.

Synthesis, Sintering, Transport Properties and Surface Exchange of La₂Ni_0.9Cu_0.1O4+δ

Zuoan Li, Truls Norby and Reidar Haugsrud

These researchers from the University of Oslo used a wet chemical method with optimized ratios of citrate to nitrate and sintering to synthesize dense La₂Ni_0.9Cu_0.1O4+δ ceramics. They report that less citrate decreases the required sintering temperature and improves oxygen permeation. They also report that the oxygen self-diffusion coefficient, oxygen chemical diffusion coefficient and surface exchange coefficient show Arrhenius-type behaviors.

Schematic diagram of experimental set-up. Credit: JACerS; Wiley.

Capacitance Enhancement of Doped Barium Titanate Dielectrics and Multilayer Ceramic Capacitors by aPost-Sintering Thermo-Mechanical Treatment

Olivier Guillon, Jaemyung Chang, Silke Schaab and Suk-Joong L. Kang

This research team from Germany and the Republic of Korea applied a postsintering uniaxial mechanical load to dielectrics and multilayer ceramic capacitors during their cooling to room temperature from either below or above the Curie temperature. The team reports that after load release, the permittivity permanently increased at room temperature by about 8 to 11 percent.

Scanning electron micrograph showing the microstructure of β-eucryptite after etching. An average grain size of about 2 μm is observed. Credit: JACerS; Wiley.

Determining Activation Volume for the Pressure-Induced Phase Transformation in β-Eucryptite through Nanoindentation

Subramanian Ramalingam, Ivar E. Reimanis and Corinne E. Packard

These researchers from the Colorado School of Mines performed hundreds of low-load nanoindentation tests on polycrystalline and single-crystal β-LiAlSiO₄ to characterize its reversible pressure-induced phase transformation to ε-LiAlSiO₄. They report that higher loading rates suppress the deviation from isotropic elastic behavior-a signature of a thermally activated process-and that reversible hysteretic loops occur in the load-displacement curves-consistent with a reversible process during nanoindentation, namely, the phase transformation.

TMA results for selected K- and Na-activated samples with H2O/Al2O3 = 11. Credit: JACerS; Wiley.

Effects of Water Content and Chemical Composition on Structural Properties of Alkaline Activated Metakaolin-Based Geopolymers

Maricela Lizcano, Andres Gonzalez, Sandip Basu, Karen Lozano and Miladin Radovic

A team from Texas A&M University and the University of Texas-Pan American evaluated the effects of chemistry as well as curing and aging conditions on water-loss kinetics, porosity and geopolymer (prepared from a metakaolin and potassium or sodium silicate solutions) structure. The team reports that the amount of water in the initial geopolymer mixture is the most dominant factor that affects density and open porosity of geopolymers after curing and aging and that the SiO₂/Al₂O₃ molar ratio has no direct effect on density and open porosity of the geopolymers.

The structure of ZnO/IDT/NKN-ST-based surface acoustic wave devices. Credit: JACerS; Wiley.

Deposition of Preferred-Orientation ZnO Films on the Lead-Free Ceramic Substrates and Its Effects on the Properties of Surface Acoustic Wave Devices

I-Hao Chan, Jen-Chuan Chang, Chieh-Tze Sun, Mau-Phon Houng and Sheng-Yuan Chu

These researchers from Taiwan used radio-frequency sputtering to grow polycrystalline ZnO films with c-axis orientation on NKN-SrTiO₃ ceramic substrates. They report that the preferred oriented ZnO film is beneficial for improving the electromechanical coupling coefficient of surface acoustic wave devices.

Calculated solvus curve and critical temperature, Τc, of (CaxSr1-x)TiO3 solid solution. Credit: JACerS; Wiley.

Thermochemistry of (Ca_xSr_1-x)TiO₃, (Ba_xSr_1-x)TiO₃, and (Ba_xCa_1-x)TiO₃ Perovskite Solid Solutions

Nissim U. Navi, Roni Z. Shneck, Tatiana Y. Shvareva, Giora Kimmel, Jacob Zabicky, Moshe H. Mintz and Alexandra Navrotsky

This University of California-Davis and Israel research team used high-temperature solution calorimetry in molten 3Na₂O∙MoO₃ solvent to show positive enthalpy of mixing of (Ca_xSr_1-x)TiO₃ and (Ba_xSr_1-x)TiO₃ solid solutions. The team reports the tendency of SrTiO₃ and BaTiO₃ to separate from a CaTiO₃ host matrix, which may be significant in perovskite-bearing nuclear waste ceramics incorporating 90Sr and 137Ba.

Share

Perena Gouma, a professor at SUNY Stony Brook, uses electrospinning to synthesize ceramic nanowires that can detect disease markers like ammonia and acetone. Credit: Science Nation; NSF.

Chances are that you know a Type 1 diabetic who endures several finger pricks every day to monitor blood sugar levels. Maybe you know someone with asthma, or perhaps you know or heard of a healthy-seeming person who got the dreaded cancer diagnosis before showing any apparent symptoms. Don’t we all suffer some anxiety when the doctor asks “to run a few tests,” knowing that needles and possibly other unpleasant invasions are inevitable? And don’t we tend to release a big-breath sigh on such occasions?

If Professor Perena Gouma is nearby, she might ask you to do it again-but this time into her Single Breath Disease Diagnostics Breathalyzer. The instrument, which her team has been developing with NSF funding at the State University of New York at Stony Brook, analyzes the volatile organic compounds that we exhale with every breath and tests for certain markers that may indicate disease. For example, ammonia is a marker for possible kidney disorders, acetone is associated with diabetes and hospitals use nitric oxide detectors to monitor pulmonary disorders. (Undoubtedly, CTT readers have only academic knowledge of alcohol-detecting breathalyzers.)

The functionality of Gouma’s device is a sensor chip that is coated with spaghetti-like nanowires. The nanowires, with their enormous surface area, are able to detect very small amounts of marker molecules. In a NSF story and video about her work, Gouma says, “These nanowires enable the sensor to detect just a few molecules of the disease marker gas in a ’sea’ of billions of molecules of other compounds that the breath consists of.”

Gouma is studying oxides in the ReO₃ family, such as α-MoO₃ and ε-WO₃. The nanowires are synthesized by electrospinning, a process in which a liquid is squirted into an electric field, crystallized as it passes through and collected on an aluminum plate. (See the video at about the 1:32 minute mark to see the process.)

In an article to be published in The Bulletin this September, Gouma explains how gas sensing properties of ReO₃ compounds arise from their perovskite crystal chemistry, nanocrystalline structure and their metastable phases.

Currently, the device is shoebox-size, but it is still in the prototyping phase, and units for detecting acetone (diabetes) and ammonia (dialysis monitoring) are being evaluated clinically. Gouma’s ambition is for these devices to be available for home use at a price point under $20. In the story she says, “People can get something over the counter, and it’s going to be a ‘first response’ or ‘first detection’ type of device. This is really a nanomedicine application that is affordable because it is based on inexpensive ceramic materials that can be mass produced at low cost.”

Echoing the exhortation of the Max Planck Society’s Peter Gruss to invest in basic science to spur innovation, Janice Hicks, a program director at NSF, says in the NSF story, “This concept could not have been realized without a fundamental understanding of the material used to create the miniaturized gas detectors. The research transcends traditional scientific and engineering disciplines, and may lead to new applications or diagnostics.”

“There will be so many other applications we haven’t envisioned. It’s very exciting; it’s a whole new world,” she says. Gouma expects that electrospun ceramic nanofibers also can be used to detect small things that are bigger than molecules, such as infectious viruses, Salmonella, E. coli and anthrax.

Her technology was among the first awardees of the NSF’s new Innovation Corps initiative, which is designed to help university researchers learn the skills they need to cross the “valley of death” and transition their concepts into marketable innovations. For this project, she is using electrospun nanofibers deposited on photocatalytic grids to clean water polluted by petroleum hydrocarbons.

For more information on electrospinning and electrospun nanowires, see

• UAB group demonstrates techniques to electrospin improved 3D tissue engineering scaffolds

• Inexpensive radial ZnO nanowire brushes ’scrub’ toxic compounds from water

• MemPro’s ceramic catalytic converters get NSF boost

• Video of the week - Electrospinning

• Fuel cells: Will a nanowire net cut catalyst costs?

Share