"Currently, food heated in a microwave loses heat to the cold dish because the dishes are transparent to microwaves," says Sridhar Komarneni, distinguished professor of clay mineralogy, College of Agricultural Sciences at Penn State. "The plates are still cool when the cooking is completed."
Materials are transparent to microwaves because the microwaves do not interact with the molecules in standard tableware. With liquids like water, the microwaves cause the molecules to move back and forth creating heat.
Komarneni, working with Hiroaki Katsuki and Nobuaki Kamochi, Saga Ceramic Research Laboratory, Saga, Japan, developed a ceramic from petalite and magnetite sintered together that heats up in the microwave without causing equipment problems the way most metals do.
They report their material in a recent issue of Chemistry of Materials.
Petalite is a commonly occurring mineral that contains lithium, aluminum and silicon and is often used to make thermal shock resistant ceramics because it expands very little when heated. Ceramic sintering uses powdered minerals pressed together hard to form green bodies. These green objects are fired first at low and then high temperatures.
When the petalite and magnetite are fired together, the magnetite converts to an iron oxide that heats up when placed in a microwave.
A rice cooker made of this material cooked rice in half the time it normally takes in a non-heating microwave rice cooker.
"Rice cooks very well with these dishes," says Komarneni who is also a member of Penn State's Materials Research Institute. "Dishes heated by themselves or with food could keep the food hot of up to 15 minutes. One might even cook a pizza on a plate and then deliver it hot."
However, those accustomed to cooking in a microwave will need to remember that the plates are hot and will burn bare hands. Potholders are again necessary.
Food preparation applications abound. A company in Arita, Japan -- long a locus of ceramic manufacturing -- called Asahi Ceramics Research Company is manufacturing microwave ware.
The material's microwave heating properties suggest another use. Because the material expands very little when heated, the petalite magnetite material does not shatter under rapid microwave heating and cooling as other materials might. The researchers created a plate of the petalite magnetite ceramic and coated the solid plate structure with cooking oil. After heating for 120 seconds, 98 percent of the oil was gone, decomposed into its components.
"We used cooking oil because it is an innocuous substance," says Komarneni. "We could, perhaps, use this material in a closed system to decompose organic contaminants in soil or dirt."
The researchers believe that once optimized, the material could be used for a variety of remediation applications at a lower energy cost and with less residue than many current methods.
A'ndrea Elyse Messer | EurekAlert!
The stacked colour sensor
16.11.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
Counterfeits and product piracy can be prevented by security features, such as printed 3-D microstructures
16.11.2017 | Karlsruher Institut für Technologie (KIT)
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses