Published on December 10th, 2013 | Edited By: Eileen De Guire
ACerS president David Green—a materials scientist by training—speaks to the President’s Council of Student Advisors in Montreal, most of whom are materials scientists in training. What makes any of them ceramic engineers? (Image above: Richard Brow, then ACerS president, with the PCSA in Montreal 2013.) Credits: ACerS.
ACerS president David Green is not a ceramic engineer. He holds a BS in chemistry and BS, MS, and PhD degrees in materials science. He describes his undergraduate MSE degree as a metallurgy curriculum with a polymers course added in. No ceramics.
In fact, he told me in a recent interview that he did not encounter ceramics until he started graduate school, and then only because there were no metallurgy projects on the topic that interested him the most—fracture. Instead, a metallurgy professor directed Green to a guy down the hall who had a project on fracture, but fracture of ceramics. “And I said, ‘Ceramics? What the heck are ceramics?’“ Green recounts with a laugh.
Green was accepted on the project to study fracture of zirconia. “I didn’t know anything about ceramics. I didn’t know anything about zirconia, but it was fracture, so—OK. I can count very closely to the day when I started my ceramic career. It was when I took on this project with Dr. Pat Nicholson and started working on fracture of zirconia at McMaster University in Canada. That’s how I got involved in ceramics,” he recalls.
Clearly, Green has identified himself as a ceramic engineer and scientist ever since that auspicious start. To me, the story begs the question—What is a ceramic engineer? (This includes glass scientists, too, of course.)
I am a ceramic engineer. I base my claim on two diplomas stating as much and my having worked as a glass researcher for a few years a long time ago. Green, on the other hand, has worked on ceramic materials his entire working career, even though his diplomas are in the more general field of materials science.
As surely as oxidation persists, ceramic and glass materials will be here to stay. However, ceramic engineering programs are not. In the United States, for example, most ceramic engineering and metallurgy programs have been absorbed into materials science and engineering departments. The Society was founded 115 years ago to meet the professional needs of those who worked on ceramic and glass materials. At the time of ACerS founding in 1898, only one ceramic engineering program existed in the US—Ohio State University’s five-year old Clay-Working and Ceramics Department. Evolution has brought us to a similar situation, and today the Society has a similar mission.
So, what makes someone a ceramic materials engineer or scientist?
How about this list?
A ceramic engineer
· Works on materials that are inorganic and nonmetallic
· Works on functional and structural materials (as opposed to condensed matter, for example)
· Is multidisciplinary, often working at the intersection of two fields such as materials and electronics or construction or biomedicine. This includes the intersection of material families, such as metals and ceramics.
· Is an enabler (refractories, for example, enable process metallurgy, heat treating, etc.)
· Is unique, specialized, smart, different, a team player, rare.
What do those of us who call ourselves ceramic or glass engineers and scientists think it takes to be one of us? What does it take to know enough about ceramics or glass to claim the expertise?
I want to know what you think.
What is a ceramic engineer? What makes YOU a ceramic engineer?
The National Institute of Standards and Technology recently selected a consortium led by Northwestern University to establish a new NIST-sponsored center of excellence for advanced materials research. The new Center for Hierarchical Materials Design will be funded in part by a $25 million award from NIST over five years. The new center will focus on developing the next generation of computational tools, databases and experimental techniques to enable “materials by design,” one of the primary goals of the administration’s Materials Genome Initiative (MGI). Work will encompass both inorganic and organic advanced materials in fields as diverse as self-assembled biomaterials, smart materials for self-assembled circuit designs, organic photovoltaic materials, advanced ceramics and metal alloys. Other members of the consortium include the University of Chicago, the Northwestern-Argonne Institute of Science and Engineering (a partnership between Northwestern and the Department of Energy’s Argonne National Laboratory) and the Computation Institute (a partnership between the University of Chicago and Argonne.) The consortium also plans to work closely with QuesTek Innovations, a small business spin-off of NU; ASM International; and Fayetteville State University.
Following on the announcement earlier this year of shape memory in zirconia, a research team at Lawrence Berkeley National Laboratory has discovered a way to introduce a recoverable strain into bismuth ferrite of up to 14% on the nanoscale. The effect, larger than any shape-memory effect observed in a metal, is said to open the door to applications in a wide range of fields, including medical, energy and electronics. Bismuth ferrite is a multiferroic compound that displays both ferroelectric and ferromagnetic properties, meaning it will respond to the application of external electric or magnetic fields. In this latest study, in addition to the conventional thermal activation, an elastic-like phase transition was introduced into bismuth ferrite using only an electric field.
Hydrogen burns cleanly and can generate electricity via fuel cells. One way to sustainably produce hydrogen is by splitting water molecules using the renewable power of sunlight, but scientists are still learning how to control and optimize this reaction with catalysts. At the National Synchrotron Light Source, researchers from Columbia University, Harvard University, and Brookhaven National Laboratory used X-rays to better understand the intermediate-range nanoscale structure of cobalt phosphate and cobalt borate thin films, two promising catalyst candidate materials. The scientists report that the borate films consist of 3–4 nm cobalt–oxygen clusters that stack neatly up to three layers deep. The phosphate films consist of significantly smaller clusters that do not stack in an ordered way. These structural differences seem to tie into the films’ catalytic activity: as film thickness increased, the borate films were more active than phosphate and ultimately displayed a “significantly superior” performance. The findings suggest that the increase in borate film thickness also increases the effective surface area available for catalysis, while at the same time preserving the charge-transport properties of the films, the scientists say.
A Northwestern University research team has produced near-perfect single crystals out of nanoparticles and DNA. Although they worked with gold nanoparticles, the researchers say the general “recipe” for single crystal production allows unprecedented control over the type and shape of crystals that can be produced and can be applied to a variety of materials with potential applications in photonics, electronics, and catalysis, the scientists say. To achieve a self-assembling single crystal in the lab, the research team used two sets of gold nanoparticles outfitted with complementary DNA linker strands. Working with approximately 1 million nanoparticles in water, they heated the solution to just above the DNA linkers’ melting point and then cooled it to room temperature over a period of days. The very slow cooling process encouraged the single-stranded DNA to find its complement, resulting in a high-quality single crystal approximately 3 μm wide.
Semiconductor nanowires have potential as laser materials for applications in computing, communications, and sensing, according to scientists at the Technische Universität München. The III-IV semiconductor nanowires can be grown directly on silicon, presenting opportunities for integrated photonics and optoelectronics, and operate at room temperature. They are said to have a tailored core-shell structure that enables them to act both as lasers, generating coherent pulses of light, and as waveguides similar to optical fibers. Potential applications for nanowire lasers include on-chip optical interconnects or even optical transistors to speed up computers, integrated optoelectronics for fiber-optic communications, and laser arrays with steerable beams. Ongoing research is directed toward better understanding the physical phenomena at work in such devices as well as toward creating electrically injected nanowire lasers, optimizing their performance, and integrating them with platforms for silicon photonics.
Published on December 6th, 2013 | Edited By: Eileen De Guire
Simulated vane rheometer. The blades rotate clockwise in the simulation, and suspended spheres are color coded for their originating octant. The yellow indicates low-stress regions, while green represents high-stress regions. Credit: NIST.
The Department of Energy recently announced (pdf) the award of 6 billion core hours of supercomputing time for 59 projects “to accelerate scientific discovery and innovation” through its Innovative and Novel Computational Impact on Theory and Experiment (INCITE) program, now in its tenth year, including one to ACerS Cements Division member Edward Garboczi and his team at NIST. The supercomputers are located Oak Ridge National Laboratory and Argonne National Laboratory.
In the announcement press release, Michael Papka, director of Argonne’s computing facility, says “The INCITE program addresses the largest, most computationally pressing projects in science and engineering.”
Such descriptions tend to conjure images of exotic nanomaterials, metamaterials, and other weird compounds—not a material as ubiquitous as concrete. However, the NIST team was awarded 40 million hours per year for two years for Phase III of a study on concrete rheology.
The key to achieving a strong, durable concrete rests on the careful proportioning and mixing of the ingredients. A concrete mixture that does not have enough paste to fill all the voids between the aggregates will be difficult to place and will produce rough, honeycombed surfaces and porous concrete. A mixture with an excess of cement paste will be easy to place and will produce a smooth surface; however, the resulting concrete will be more likely to crack and be uneconomical.
A properly proportioned concrete mixture will possess the desired workability for the fresh concrete and the required durability and strength for the hardened concrete. Typically, a mixture is by volume about 10 to 15 percent cement, 60 to 75 percent aggregates and 15 to 20 percent water. Entrained air bubbles in many concrete mixtures may also take up another 5 to 8 percent.
Portland cement’s chemistry comes to life in the presence of water. Cement and water form a paste that surrounds and binds each particle of sand and stone. Through a chemical reaction of cement and water called hydration, the paste hardens and gains strength.
The character of concrete is determined by the quality of the paste. The strength of the paste, in turn, depends on the ratio of water to cement. The water-cement ratio is the weight of the mixing water divided by the weight of the cement. High-quality concrete is produced by lowering the water-cement ratio as much as possible without sacrificing the workability of fresh concrete. Generally, using less water produces a higher quality concrete provided the concrete is properly placed, consolidated and cured.
Garboczi and his NIST colleagues are using sophisticated computational methods to optimize the instruments used to measure concrete rheology. The team provided the following summary of the challenges involved in measuring rheology, which trace back to rheometer design parameters, and how new rheometers might be designed using advanced methods like additive manufacturing. The work applies beyond concrete, too.
For more information, see the publication list at the end, or Garboczi’s article in the May 2013 ACerS Bulletin.
Computational design of novel mortar and concrete rheometers: Bridging the length scales of concrete rheology
By Edward Garboczi, Nicos Martys, Judith Terrill, and William George
A team of researchers from NIST’s Information Technology Laboratory (ITL) and Engineering Laboratory (EL) have been awarded 40 million hours of computer time per year for 2014 and 2015 from the Department of Energy (DOE) to support the study of the design of rheometers for large-particle dense suspensions such as concrete. The award is the result of a proposal submitted to DOE’s peer reviewed INCITE program and is the third straight INCITE award for this team and general topic. The research team includes William George, Marc Olano, Steven Satterfield, and Judith Terrill of ITL, Nicos Martys and Edward Garboczi of EL, and Pascal Hebraud of CNRS/ESPCI (France). The simulations will be run in the Leadership Computing Facility of Argonne National Laboratory on ‘Mira’, an IBM Blue Gene/Q system currently ranked number 5 in the “Top 500“ list of supercomputer installations.
Accurately measuring the rheology of dense suspensions like concrete is a crucial and widespread problem in the construction and other industries. Two rheological parameters, plastic viscosity and yield stress, are necessary to explain and predict fresh concrete flow properties or indeed almost any dense suspension. However, the usual rheometer geometry used, a spinning vane with some shape blade, does not permit an analytical solution of internal fluid flow, so that neither fundamental rheological parameter can be measured. In the first INCITE phase of this work (3 years, 2.25 million hours) , the basic smooth-particle hydrodynamics computations needed to compute the shear rheology of complex suspensions consisting of a non-Newtonian matrix fluid and a high volume fraction of solid particles (either model spheres or real industrial mineral shapes) were developed and validated. Phase II (3 years, 70 million hours) applied these computations to common industrial rheometers and used the results to design standard reference materials for dense suspensions that can be used to convert empirical experimental measurements into fundamental rheological quantities. In both cases, massively parallel computations were needed to handle the large number of particles and the complex particle-particle interactions necessary for an accurate simulation.
In the just-awarded Phase III INCITE award, computations will be run to design the actual vane rheometer blades themselves and optimize their shape and rotational speed so as to avoid artifacts like sedimentation, particle segregation, and low-shear regions that are present in currently available rheometers. Novel, non-traditional rheometer blade designs, suggested by the simulations, which look nothing like current blade designs, will be built using additive manufacturing processes. This opens up the potential design space, leading to an almost unlimited range of possibilities. Massively parallel computations are needed to guide this manufacturing design and fabrication process, so as to produce optimal rheometers for practical industrial use. NIST has the capability to manufacture these new designs, as well as perform experimental validation of the predicted rheological measurements produced by these novel rheometer blade designs. The results of this work will also be useful for the many industries that make use of dense, complex suspensions, such as food processing, water treatment, coatings, ceramic processing, and pharmaceuticals.
Finally, an integral part of this work, over all three INCITE phases, has been to break down the multi-scale dense suspension material problem into manageable chunks and then reunite the major length scales of concrete rheology: cement paste, mortar, and concrete. Each length scale (cement paste—100s of micrometers, mortar—millimeters, concrete—hundreds of millimeters) has its own separate rheological behavior and complexities and its own rheometers. Cement paste (cement plus water plus chemical additives) is a non-Newtonian fluid with fundamental properties that can be measured with standard parallel plate rheometers. Mortar is modeled as a sand suspension in a cement paste fluid matrix with measured properties, while concrete is considered to be a gravel suspension in a mortar fluid matrix. The Phase III simulations will unite these length scales for traditional and novel rheometer designs, with the aid of computationally-designed standard reference materials and rheometers for each length scale.
Selection of papers associated with this project:
N.S. Martys, M. Khalil, W.L. George, D. Lootens and P. Hébraud, “Stress propagation in a concentrated colloidal suspension under shear,” Eur. Phys. J. E Volume 35, No 3, 12012-12020, 2012.
N. S. Martys, D.Lootens, W. L. George, S.G. Satterfield, P. Hebraud, “Spatial-Temporal Correlations at the Onset of Flow in Concentrated Suspensions,” XVth Inter. Cong. on Rheology, Ed. A. Co, L. G. Leal, R. H. Colby, A. J. Giacomin, AIP Conf Proc. vol 1027, Monterey, CA, pp. 207-209, 2008.
D. Lootens, N. S. Martys, W. George, S. Satterfield, P.Hebraud, “Stress Chains Formation under Shear of Concentrated Suspension,” XVth Inter. Cong. on Rheology, Ed. A. Co, L. G. Leal, R. H. Colby, A. J. Giacomin, AIP Conf Proc. vol 1027, Monterey, CA, pp. 677-679, 2008.
S. T. Erdogan, N. S. Martys, C. F. Ferraris, D. W. Fowler, “Influence of the shape and roughness of inclusions on the rheological properties of a cementitious suspension,” Cement & concrete composites, vol. 30, no. 5, pp. 393-402 , 2008.
Published on December 6th, 2013 | Edited By: Eileen De Guire
A technical session at ICACC’13. Credit: ACerS.
One of the largest ACerS meetings every the year is the Engineering Ceramics Division meeting, which is officially the 38th International Conference and Expo on Advanced Ceramics and Composites, although it is often referred to simply as “the Daytona Beach meeting.” Held each January in Daytona Beach, Fla., the meeting attracts more than 1,000 attendees from around the globe. Early bird registration for ICACC’14, slated for January 26–31, runs through Dec. 19.
Sanjay Mathur, who organized the 2012 ICACC and is on this year’s organizing committee, says, “The ICACC meetings have emerged as an authentic platform to experience and enjoy the evolution of ceramics science and technology. The unique constellation of thematic areas and international gathering speaks for the high visibility and importance of this conference both for showcasing state-of-the-art scientific results as well as for building new contacts with peers worldwide.”
A subtitle for this meeting could be “Look what ceramics can do!” The technical program covers functional and structural ceramics, processing, and applications, including topics such as armor, bioceramics, porous ceramics, ultrahigh temperature ceramics, and more. The importance of ceramics for energy generation and storage is evident in symposia on SOFC, rechargeable energy storage, and nuclear and fusion energy. Computational methods and the “Ceramic Genome” will be covered, as will advanced processing and manufacturing techniques.
Organizer Michael Halbig and his team included four “focus sessions,” which are symposia on specialized topics of emerging interest. Over the years, some of these have turned into regular symposia, but their real value is in providing a way to address rapidly developing issues. This year’s four focus sessions are
The plenary and award speakers are always a highlight of the first day. This year is no exception, with these luminaries of the ceramics world.
Sheldon Wiederhorn—Mueller Award, “From the Rattler Test to Modern Fracture Mechanics: A Perspective on Toughness,”
José Varela—Bridge Building Award, “Building Bridges in Materials Science and Technology: An Important Issue for Solving Basic Problems in Modern Society,”
Willard Cutler—Plenary speaker, “The Need and Potential of Porous Ceramic Materials,”
Ulrich Simon—Plenary speaker, “Nanostructured Metal Oxides in Gas Sensing Applications: Challenges and Perspectives”
Eva Hemmer—Global Young Investigator Award, “Ln3+-Doped Gd2O3 Nanostructures for NIR-NIR Bioimaging.”
The Global Young Investigators Forum is a great place to meet the rising leaders in ceramics. It is organized by Thomas Fischer from the University of Cologne, Germany, who also organized the first forum in 2012. At the 2012 ICACC he told me the goal is to engage young scientists more fully in the conference, saying “Normally at conferences you have established scientists and huge sessions, and it’s a little bit of a barrier. We wanted to lower this barrier by having a session on our own, but one where the established scientists also take part.” A second goal, he says is to create “a venue where young people can meet and try to find their own networks.”
This year’ Engineering Ceramics Summit focuses on the Pacific Rim, which is a nice follow-up to last year’s PACRIM 10 meeting in San Diego, Calif.
The Expo will welcome more than 50 vendors showcasing their products and services. Students will have their annual shot glass dropping competition (sponsored, appropriately, by Schott Glass) during the Expo.
Finally, world-renowned experts in mechanical properties, George Quinn and Richard Bradt, will wrap up the conference activities with their popular short course on mechanical properties of ceramics and glass on January 30–31. A central part of the course covers mechanical testing and interpretation of test data.
Amedica Corp. will collaborate with Kyocera Industrial Ceramics Corp. to manufacture medical devices from Amedica’s silicon nitride biomaterial at Kyocera’s Vancouver, Wash., facility. The deal includes production of Amedica’s FDA-approved Si3N4 spinal interbody devices. Silicon nitride biomaterials promote bone growth and have anti-infection properties, according to Amedica. Devices made from the material are semi-radiolucent with clearly visible boundaries, enabling an exact view of intraoperative placement and postoperative fusion assessment via common imaging modalities. The company says says it has already sold more than 14,000 spinal interbody devices worldwide, and it is seeking to ensure a consistent supply of the devices as demand grows.
New manufacturing capabilities enable production of large piezoelectric ceramic blocks for defense and commercial sonar applications, according to Morgan Advanced Ceramics. The company says it can press, fire, and machine blocks and other shapes up to 45 mm thick, components considerably larger than those it could previously manufacture. According to Morgan, the larger blocks offer lower thickness frequency output than their smaller counterparts, resulting in enhanced sonar imagery and range at lower depths. Typically supplied with fired-on silver electrodes to ensure good adhesion and durability, the components can also be manufactured with evaporated nickel electrodes.
(Area Development Online) Nanova Biomaterials Inc., a startup company in Columbia, Mo., plans a $1.5 million expansion of its production center and creation of 50 jobs in the next five years. The company uses nanotechnology to manufacture orthopedic and dental products, such as dental filling materials and bone screws. Its parent company, Nanova Inc., was founded in 2007, and Nanova Biomaterials was launched in 2013 to focus on nanotechnology research.
Advanced Ceramics to 2017 is the title of a new market research report that forecasts US demand for advanced ceramic materials will increase more than five percent annually to $13.5 billion in 2017. The study forecasts market size for 2022, and presents historical demand data for 2002, 2007, and 2012 for various materials and material types, processes, and applications. According to the report, demand for advanced ceramics in the US will be driven by above-average growth in the machinery, transportation, and medical markets, as well as accelerating growth in electrical and electronic components applications. The report also profiles 36 US ceramics industry suppliers.
(Ventures Africa)West African Ceramics Ltd. will invest more than $50 million to build a state-of-the-art ceramic tile factory in Ogun state, western Nigeria. According to a report, the new facility will meet rising demand for European standard quality tiles in Nigeria and across sub-Saharan West Africa. The company says its current factory in Nigeria’s Kogi state is operating to capacity, and that availability of large quantities of raw materials in Ogun State makes the area a potential commercial hub.
Published on December 5th, 2013 | Edited By: Jim Destefani
A couple of weeks ago, Eileen reported on how physics—specifically, fluid dynamics—applied to the question of what makes a teakettle whistle could one day help reduce unwanted noise from, for example, pipes in buildings or high-speed hand dryers.
This week, the focus is on a beverage many would argue is more fun than tea, and nearly as popular. According to a news release from the American Physical Society, scientists have gone to work to gain insight on the age-old phenomenon of copious amounts of foam spewing from “tapped” beer bottles.
The answer once again lies in the science of fluid dynamics—in this case, the phenomenon of cavitation. Researchers from Spain’s Carlos III University and France’s Université Pierre et Marie Curie presented their foamy findings on the topic at the recent annual meeting of APS’s Division of Fluid Dynamics and explain their results in the video above.
As it demonstrates (and as many of us have experienced first-hand), a sudden impact against a bottle’s mouth can cause the bubbly brew inside to spew all over the place. According to the APS news release, “back and forth movement of compression and expansion waves will cause bubbles to appear and quickly collapse. The team’s investigation of beer bottle–fluid interactions demonstrated that the cavitation-induced break-up of larger ‘mother’ bubbles creates clouds of very small carbonic gas ‘daughter bubbles,’ which grow and expand much faster than the larger mother-bubbles from which they split.”
It’s these smaller, faster-growing bubbles that give the foam buoyancy, and “buoyancy leads to the formation of plumes full of bubbles, whose shape resembles very much the mushrooms seen after powerful explosions,” lead researcher Javier Rodriguez-Rodriguez explains. “And here is what really makes the formation of foam so explosive: the larger the bubbles get, the faster they rise, and the other way around.”
The research may seem like a long way to go to explain what is basically a happy hour prank, but the researchers were earnest enough to focus a high-energy laser pulse inside a bottle of suds to produce the same results as “tapping.” Similarly, their findings might see more serious application wherever, for example, cavitation erosion is a materials issue. According to the APS news release, the results might also be applicable to explaining phenomena such as the sudden release of dissolved carbon dioxide from Lake Nyos in Cameroon that killed more than 1,700 people in 1986.
Maybe you’re content simply to amaze (or possibly bore) your friends with a scientific explanation of why beer “tapping” works so explosively well. If that’s the case, enjoy in moderation, store your suds properly, and stay thirsty, my friends.
Published on December 3rd, 2013 | Edited By: Jim Destefani
A couple months ago, we reported on MFG Day and the hold that 3D printing technology seems to have taken on the imaginations of many.
Similarly, the days following the Thanksgiving holiday in the US seem to have captured the attention of the mainstream media, mostly for a series of holiday-shopping-related “special” days: Black Friday, Small Business Saturday, Cyber Monday.
For those of us who are a bit more technically oriented, General Electric, one of the world’s largest proponents of 3D printing, is now swinging the focus back to additive manufacturing technology with the first ever “3D on D3” (as in December 3rd, which happens to be today) special event on its Edison’s Desk research blog (see the screen capture above; credit: GE Research).
One way GE Research is celebrating is by giving away 3D printed holiday gifts designed by celebrities, web tech gurus, and athletes working in conjunction with its own engineers. Check out the available gifts, and learn how to try to get one using Twitter, here.
Working in conjunction with GrabCAD, the company also held a contest for a 3D, modernized redesign of Santa’s sleigh. Finalists were selected by GE engineers out of more than 50 entries. The video shows the judges discussing the merits of finalist designs and their reasons for selecting the winner. GE will be producing and giving away 200 Christmas tree ornaments based on the winning design. Once again, you’ll need to take to Twitter to try to get one.
3D on D3 may be all in fun and the spirit of the Holiday season, but GE is deadly serious about its commitment to additive manufacturing technology—by 2020, the company’s Aviation division expects to have produced more than 100,000 additive manufactured components for its latest aircraft engines. GE is also using 3D printing to produce medical device components and other parts. In this interview with additivemanufacturing.com, for example, Greg Morris explains the business decisions that led GE to commit to additive manufacturing in the new LEAP-1A engine. Morris is business development leader for additive manufacturing at GE Aviation, a position he took when he sold the company he founded, Morris Technologies, to GE in 2012. The company specialized in additive manufacturing.
By the way, we just got word that Morris will be speaking at the Ceramic Leadership Summit in April, focusing on innovation and business decisions that drive innovation and adoption of new manufacturing technologies. For a full lineup of the incredible CLS program, visit the website.
The National Science Foundation also has 3D on their minds today and published this online article about advances in additive manufacturing that trace back to NSF research projects.
Published on December 3rd, 2013 | Edited By: Eileen De Guire
We are looking for an associate editor to fill this chair!
ACerS is growing!
As a regular reader of CTT, you know there is a wealth of great news to tell about ceramic and glass materials, as well as trends in science, engineering, and business. More, it turns out, than two editors can tell. Add in the many new ways we have to get the word out, and we need another “hand on deck.”
What are we looking for? We are looking for an editor–science writer to write for Ceramic Tech Today, work with volunteer authors for the ACerS Bulletin magazine, and expand our web and electronic outreach through channels like LinkedIn, Twitter, Slideshare, etc. The new editor should have a nose for ferreting out news and trends in the materials science and engineering world and be knowledgeable in new and developing digital outreach opportunities.
Do these keyterms resonate with you or someone you know? Science writing, content marketing, digital content development, engineered ceramics, glass, materials science, materials engineering.
Published on December 3rd, 2013 | Edited By: Jim Destefani
Self-supporting ceramic nanogrid photocatalysts (SEM image, top, credit: P. Gouma/SUNY) may one day make scenes like this one, showing deployment of a containment boom at Pensacola, Fla., after the 2010 Deepwater Horizon oil spill, a thing of the past. Lower image credit: P. Nichols/U.S. Navy via Wikimedia Commons.)
We’ve all seen video of cleanup efforts resulting from oil spills large and small, from the Gulf of Mexico to local streams. Typically, cleanup involves a painstaking “mop-up” process followed by weeks or months of rehab by armies of paid employees and volunteers to repair damage to the environment.
A new product from the laboratory of a ceramic scientist and currently being readied for production by a startup company could make cleanup as simple as throwing a net over the offending oil slick. Pelagia-Irene (Perena) Gouma, professor of materials science and engineering at State University of New York Stony Brook, led a team that created a novel copper tungsten oxide nanogrid photocatalyst. Activated by sunlight, the net breaks down spilled oil, leaving behind only biodegradable compounds.
“[This] is the first time that self-supported nanostructured catalysts have been shown to clean up petroleum-based hydrocarbons in water,” Gouma writes via email. “Our technology responds to visible light (as opposed to the UV-responding industrial catalysts), it does not rely on dispersed and loose nanostructures that need to be confined or retrieved after a cleaning step, and as an oxide catalytic system it is reusable and not consumed during use. The products of the hydrocarbons clean up/water remediation are innocuous and biofriendly.”
Gouma, director of SUNY’s Center for Nanomaterials and Sensor Development, says in a National Science Foundation news release that the invention “utilizes the whole solar spectrum and can work in water for a long time, which no existing photocatalyst can do now. Ours is a unique technology. When you shine light on these grids, they begin to work and can be used over and over again.” Ships could carry the nanogrid nets, and so be able to handle their own small spills, she adds.
According to Gouma, the self-assembling nanogrids form in a multistep process that involves a combination of templating and blend electrospinning. “Upon heating, metal clusters diffuse inside polymeric nanofibers, then turn into single-crystal nanowires, then oxidize to form metal oxide—ceramic—nanoparticles that are interconnected, like links in a chain,” she says in the news release.
Gouma envisions the nanogrid photocatalyst materials being used not only to clean up oil spills but to break down other environmental contaminants, such as water used in hydrofracturing extraction of natural gas. Applications exist for more mundane applications, too, such as, for example, at-home dry cleaning. “The dry cleaning process that we now use involves a lot of contaminants that have to be remediated and treated, such as benzene,” she says in the news release. “This could be a dry cleaning substitute that would be more environmentally friendly than current dry cleaning approaches.”
She imagines users simply laying the nanogrid over articles of clothing and exposing them to light to clean them. “You won’t need a washing machine, or chemicals, or even water,” she says.
Gouma and her team have two patents pending on the nanogrid technology and have launched a startup company to commercialize production. “We are focusing on scaling up further the nanomanufacturing process while optimizing the nanogrids’ composition and properties,” she writes via email. “[The nanogrids] are currently being produced in sheets several inches wide that can be directly applied to (and be recovered from) an oil spill in water.”
This is not the first time Gouma, an ACerS member since 1997 and recent winner of the Society’s Richard M. Fulrath Award, has made news on Ceramic Tech Today. Her work developing nanosensors for disease diagnosis has been featured both here and in the September 2012 ACerS Bulletin.
More than two-thirds of the energy from primary sources like oil and gas is lost through waste heat, according to scientists at the Fraunhofer Institute for Physical Measurement Techniques IPM (Freiburg, Germany). Thermoelectric modules can make use of part of that waste heat, and researchers at the institute have devised a way to produce half-Heusler alloys—some of the most efficient thermoelectric materials—in kilogram quantities. The alloys consist of a range of materials, including nickel, and are said to be more nickel being one, and are said to be more environmentally friendly than previous materials, possess good thermoelectric properties, and withstand high temperatures. Prototypes of a thermoelectric system devised by the scientists have already converted the waste heat from an automotive exhaust into up to 600 W of electrical power, according to a news release.
Researchers at Swinburne University of Technology (Australia) say they have developed a bio-inspired black silicon material that can kill bacteria at up to 450,000 cells per minute of exposure per square centimetre of available surface. The nanostructured material is etched to create long, narrow protrusions on its surface. Surfaces with similar features are common in the natural world—in particular, the scientists studied the wing surface of the Diplacodes bipunctata dragonfly, which features spike-like nano structures that kill both rod-shaped and spherical bacteria. The mechanical antibacterial effect is unrelated to surface chemical composition, and instead works by essentially impaling the bacteria on the nanostructures, the researchers say. The approach could enable development of a new generation of antibacterial nanomaterials that could be applied to medical implants and other surfaces, they add.
Scientists working on the US Defense Advanced Research Project Agency’s integrated Photonic Delay program have demonstrated low-signal-loss, microchip-scale integrated waveguides for photonic delay. The iPhoD program resulted in creation of a new class of photonic waveguides with losses lower than those of optical fiber devices. The new waveguides are built onto microchips; conventional fiber optic coils of the same delay length would be about the size of a small juice glass, according to DARPA. The waveguides also employ modern silicon processing techniques to achieve submicron precision and more efficient manufacturing, the agency says, resulting in a new component that is smaller and more precise than anything before in its class. Photonic delays are useful in military application ranging from small navigation sensors to wideband phased-array radar and communication antennas, the agency says.
Researchers at the University of Pittsburgh have developed computational models for a polymer gel that would enable complex materials to regenerate themselves if damaged. Inspired by biological processes in species such as some amphibians, which can regenerate severed limbs, the team developed a hybrid material consisting of nanorods embedded in a polymer gel containing monomers and cross-linkers. When part of the gel is severed, the nanorods near the cut act as sensors and migrate to the new interface. Functionalized chains on one end of the nanorods keeps them localized at the interface, and sites along the rod’s surface trigger a polymerization reaction with the monomer and cross-linkers in the outer solution to repair the damage.
Typically, silicon photovoltaic cell manufacturers add a grid of thin silver lines to the cell via a screen-printing process to form the front contacts. A new design developed by researchers at the US Department of Energy’s National Renewable Energy Laboratory and solar startup TetraSun instead loads 50 μm wide copper electrodes on its front contacts in a way that prevents diffusion of the metal, which can degrade performance. The developers say the process exceeds the performance of traditional heterojunction cells without special equipment, complicated module assembly, or transparent conductive oxides. The copper electrodes are much less expensive than silver, and the process should lend itself to high-volume manufacturing, they add.