HAIFA, Israel and NEW YORK, N.Y., May 16, 2001 – Israeli researchers have begun pilot-scale production of a new high-temperature thermal ceramic insulator that may become a safe and economical substitute for asbestos and other potentially harmful ceramic fibers now in use. The new material is a ceramic foam that contains 94% to 96% air by volume, but can resist temperatures above 1700° C.
It is being developed under the direction of chemical engineering professor Gideon Grader at the Technion-Israel Institute of Technology in Haifa. Prof. Grader established a new company, Cellaris, at the Technion’s Entrepreneurial Incubator Company to produce the foam.
The devastating lung ailments, including cancer, that can be caused by asbestos have led to a search for other high-temperature insulating materials. But the ceramic fibers that have replaced asbestos also produce needle-shaped dust particles that can be dangerous to the lungs when inhaled. In contrast, the crushing of Cellaris’ ceramic foam produces ordinary dust particles similar in shape to those common in the environment, and thus do not pose the health hazards associated with ceramic fibers.
The foam is made of aluminum oxide, a common high-temperature ceramic, but gets its extraordinary insulating powers from the many tiny air bubbles within the material. (Air is a very good thermal insulator, but needs to be trapped, as in a blanket, to be effective.) The foam can be used not only for thermal insulation, but for a variety of other applications such as acoustic insulation and adsorption of environmental pollutants.
"With only four to five percent of the foam's volume taken up by the ceramic, the material is an effective insulator that can compete with today's high-end, state-of-the-art ceramic fibers," Prof. Grader explains. "Its low density can be important in applications where weight is at a premium. On a weight-for-weight comparison, the foam can offer safe, cost-effective insulation."
The foam is generated from special crystals that contain the metal components and all the foaming ingredients. Upon heating, the crystals form a solution. Within this solution a reaction takes place, forming polymer chains. After the chains grow sufficiently, the solution suddenly separates into a pure solvent and the polymer. At this point, the solvent begins to boil, forming trillions of tiny bubbles that blow the polymer into a foam, stabilized by the polymer chains. Subsequent heating to high temperatures leaves behind the ceramic, metal oxide foam.
The foam was developed in Prof. Grader’s laboratory in 1998, after years of study of porous ceramics. Government support through the Technion Entrepreneurial Incubator Company and private seed money set Cellaris in motion in January 1999. With an additional $700,000 investment from private investors, Cellaris started small-scale pilot production in February 2001. By June 2001, the company expects to produce enough material to send samples for testing to a variety of corporations in the United States and Europe that are interested in the ceramic’s possible manufacture or use.
The Technion-Israel Institute of Technology is Israel's leading scientific and technological center for applied research and education. It commands a worldwide reputation for its pioneering work in computer science, biotechnology, water-resource management, materials engineering, aerospace and medicine. The majority of the founders and managers of Israel’s high-tech companies are Technion graduates. The Technion’s 19 faculties and 30 research centers and institutes in Haifa are home to 13,000 students and 700 faculty members.
Based in New York City, the American Technion Society (ATS) is the leading American organization supporting higher education in Israel. The ATS has raised more than $800 million since its inception in 1940, more than half of that during the last eight years.
A nationwide membership organization with more than 20,000 supporters and 17 offices around the country, the ATS is driven by the belief that the economic future of Israel is in high technology and the future of high technology in Israel is at the Technion. Technion societies are located in 24 countries around the world.
Materials provided by American Society For Technion, Israel Institute Of Technology. Note: Content may be edited for style and length.
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