Professor Sridhar Komarneni at Penn State and Hiroaki Katsuki and Nobuaki Kamochi at Saga Laboratory use the process of ceramic sintering, or pressing together heated powders until the particles adhere together, to combine the petalite and magnetite into a viable ceramic. Petalite is a mineral containing several common metals including silicon, aluminum, and lithium. Magnetite is a ferrimagnetic form of iron oxide often found in large quantities in beach sand and in some mountain regions across the United States, India, Western Europe, and Africa. During the sintering process, the magnetite transforms into an iron oxide that reacts to heat.
Current microwaveable materials do not interact with the microwaves, retaining their unheated state. The cold dishes leech heat away from the food being heated as the full system strives to reach thermal equilibrium. Dishes that themselves heat up during the cooking process will not do this, lessening the amount of energy needed to bring the food to a properly heated state and also increasing the time it will remain hot once the food and plate are removed from the microwave. The down side of this process is that the plates themselves will be hot and must be handled with heat resistant materials such as the gloves and potholders currently in common use with stove top cooking vessels.
Early cooking experiments with the new material look promising. Rice cooked in a ceramic bowl took about half of the time as rice cooked in a more traditional microwave safe cookware and the rice remains piping hot for more than fifteen minutes after its removal from the microwave.
The ceramic could also potentially have other applications. Cooking oil placed on a ceramic dish decomposes into its constituent parts after two minutes of microwave cooking. The same process might be able to decompose contaminated soil, removing the contaminants and leaving the clean soil behind. Other similar environmental cleanup tasks might be possible using the material as well.
TFOT has reported on other innovative new ceramics and ceramics combined with other materials including ferroelectric polymer and ceramic-based capacitors also developed at Penn State, a new ceramic and polymer composite that’s as tough as a metal but stretches like a polymer, and a tough, ultra thin graphene paper that’s tougher than diamonds and could act as a carrier substance for ceramic, polymer, and metal mixes.
You can find out more about the new material in the Penn State news release or a shorter but more technical Penn State research note here. You can also read the full article published in the July 2008 issue of Chemical Materials here.