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A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A Y / J U N E 2 0 2 0 1 2 COMPOSITE METAL FOAMS CAN TAKE THE HEAT New research from North Caro- lina State University, Raleigh, shows that composite metal foams (CMFs) can withstand extreme amounts of heat, advancing the material’s potential for more widespread use. The foams passed simulated pool fire testing, pointing to the material’s applications for packaging and transporting hazard- ous materials. Researchers also used this experimental data to develop a model for predicting how variations in the CMF would affect its performance. In simulated pool fire testing, a panel of material is exposed to a tem- perature of at least 816°C on one side for 100 minutes. A suite of thermal sen- sors rests on the other side of the pan- el. If those protected sensors register a temperature of 427°C or higher at any point during the 100 minutes, the mate- rial fails the test. For their tests, the NC State re- searchers used panels made of steel- steel CMF. CMF is a foam that consists of hollow, metallic spheres—made of materials such as carbon steel, stainless steel, or titanium—embedded in a metallic matrix made of steel, aluminum, or other me- tallic alloys. Researchers say the CMF, which they were testing for use as a novel insulation system for transportation of HAZMAT, passed the test by a wide margin. The material may be relevant to other applications from military vehicles to architectural structures. The new research builds on pre- vious work that found CMFs are sig- nificantly more effective at insulating against high heat than conventional metal and alloy compositions, such as steel. Taken together, the findings high- light CMF’s potential for use in storing and transporting nuclear material, haz- ardous materials, explosives, and oth- er heat-sensitive materials, as well as space exploration. ncsu.edu . NOVEL MATERIAL BOOSTS SEMICONDUCTOR FUNCTIONALITY In a multidisciplinary collabo- ration with physicists from Argonne National Laboratory, Lemont, Ill., and chemists from Johns Hopkins Univer- sity, Baltimore, researchers at Rens- selaer Polytechnic Institute, Troy, N.Y., have created a controllable material promising for use in future electronics. EMERGING TECHNOLOGY A new, atomically thin materials platform developed by researchers at Penn State, State College, in conjunction with Lawrence Berkeley National Lab, Calif., and Oak Ridge National Lab, Tenn., will open a wide range of new applications in biomolecular sensing, quantum phenomena, catalysis, and nonlinear optics. mri.psu.edu . BRIEF The researchers synthesized the material—an organic-inorganic hybrid crystal made up of carbon, iodine, and lead—and then demonstrated that it was capable of two material properties previously unseen in a single material. It exhibited spontaneous electric po- larization that can be reversed when exposed to an electric field, or ferro- electricity. It simultaneously displayed a type of asymmetry known as chirality, a property that makes two distinct ob- jects mirror images of one another but not able to be superimposed. According to the Rensselaer re- searchers, this unique combination of ferroelectricity and chirality is advanta- geous. When combined with the mate- rial’s conductivity, these characteristics can enable other electrical, magnetic, or optical properties. “What we have done here is equip a ferroelectric material with extra func- tionality, allowing it to be manipulated in previously impossible ways,” the re- searchers say. A ferroelectric material with chi- rality can be manipulated to respond differently to directional light so that it produces specific electric and magnet- ic properties. This type of light-matter interaction is particularly promising for future communication and computing technologies. rpi.edu , anl.gov, jhu.edu. Steel-steel composite foam samples after 100 minutes of exposure to 825°C (left) versus before testing (right). Courtesy of Afsaneh Rabiei/NC State University. A single atomic layer of metal is capped by a layer of graphene, allowing for new layeredmaterials with unique properties. Courtesy of Natalie Briggs/Penn State.