NEWS OF THE WEEK
PREPARING HIGHQUALITY GRAPHENE FLEXIBLE ELECTRONICS: New methods could yield agile devices from carbon-based films
JI HYE HONG/N AT U R E
T Patterned graphene films grown by a new method are easily transferred to polymers and other supports.
WO METHODS for preparing large high-quality
films of graphene may lead to inexpensive, largearea solar cells, displays, and other electronic devices that can be flexed, bent, and folded for storage. The optical transparency and electronic conductivity of graphene—one-atom-thick sheets of carbon that make up graphite—make it an attractive candidate for flexible, transparent electrodes. Peeling apart graphite crystals to liberate individual graphene sheets leads to samples with outstanding properties. But that method is cumbersome and unsuitable for large-scale manufacturing. Graphene can also be prepared via self-assembly and chemical methods, but those techniques have not produced centimeter-sized high-quality samples. Now, two new methods can be used to prepare high-quality films measuring hundreds of square centimeters. At Northwestern University, materials scientists
CHEMICAL MAKERS STAGE MORE CUTS RESTRUCTURING: Economic downturn
brings additional job reductions
POLYONE
Markets for under-the-hood automotive parts, including those made with materials from PolyOne, are declining.
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OUR U.S.-BASED chemical companies are cut-
ting jobs and scaling back production as end-use markets continue to soften. For two of the firms, these actions are repeat attempts to address stagnating economic conditions. Rohm and Haas hopes to save $90 million through its latest actions, which build upon others announced in June 2008. The company is curtailing production and will idle or close underutilized plants. It will cut its workforce by about 5%, or 900 jobs, companywide, excluding its salt business, and it will freeze some discretionary spending and salaries. “We will continue to control costs in order to compete effectively while preserving our capacity to accelerate performance when markets recover,” President Pierre R. Brondeau says. Meanwhile, PolyOne is again trying to mitigate the effects of waning demand, particularly in housing and automotive markets. A July 2008 manufacturing realignment targeted a WWW.CEN-ONLINE.ORG
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Jiaxing Huang, Laura J. Cote, and Franklin Kim showed that corralling individual waterborne films of graphite oxide, a common graphene precursor, causes the films to coalesce into a single-layer, close-packed continuous sheet. Huang’s group demonstrated that the product film, which in this study measured hundreds of square centimeters, can be readily transferred to a substrate and then reduced to high-quality graphene (J. Am. Chem. Soc., DOI: 10.1021/ja806262m). In the other investigation, Byung Hee Hong of Sungkyunkwan University, in Suwon, South Korea, and coworkers grew centimeter-sized patterned graphene films by using chemical vapor deposition to react methane and hydrogen on a prepatterned nickel support. The group etched away the nickel with an iron chloride solution, transferred the films to other substrates, and showed that, even upon bending and stretching, the films retain their useful properties. Some of the samples exhibited a 30-fold decrease in electrical resistance compared with films made by other methods (Nature, DOI: 10.1038/nature07719). Richard B. Kaner, a chemistry professor at the University of California, Los Angeles, notes that graphene could lead to a new generation of carbon-based electronic materials if methods can be developed to make it inexpensively, in large quantities, and with excellent electronic properties. “These papers represent very important contributions toward this goal,” he says.—MITCH JACOBY
largely U.S.-based downturn but has proved insufficient against “a precipitous decline in global demand,” according to CEO Stephen D. Newlin. Additional steps are needed, he says, “to prepare ourselves for what may be a prolonged economic downturn.” As part of a new effort to save about $40 million annually, PolyOne will trim 8% of its workforce, or about 370 jobs, reduce the work schedules of another 100 to 300 employees, and freeze executive salaries. The company will close its Niagara, Ontario, vinyl compounds plant and idle other capacity. Some of the biggest cuts will come at Huntsman Corp., which by year-end will eliminate 1,175 positions, or about 9% of its employees, plus 490 contractors. Along with shutting down its Grimsby, U.K., titanium dioxide plant, these moves should generate about $150 million in cost savings. Nalco, meanwhile, has completed a reorganization that has created a new water and process services division and has removed 400 jobs since Oct. 1, 2008. Annual savings are expected to total more than $40 million. Chemical companies are acting swiftly, pulling all the available “levers,” and taking tough steps to control costs, says Tim Hanley, vice chairman and U.S. process and industrial products leader at Deloitte. “This downturn is increasingly challenging because it is in the midst of a financial crisis, and these companies have to be mindful of their liquidity,” Hanley says.—ANN THAYER
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