NEWS OF THE WEEK MATERIALS
CHEMISTRY
TINY CRYSTALS IN LARGE QUANTITIES Method produces monodisperse nanocrystals on multigram scale
troscopy and other analytical methods, Hyeon and coworkers determined that particle nucleation tends to occur at lower temperatures (about 2 0 0 - 2 4 0 °C) than crystal growth (about 300 °C).That information enabled the team to separate the crystal nucleation and growth processes and thereby control the monodispersity of the products. For example, by carrying out a series ofreactions usingfivesolvents with a range of boiling points, the group produced iron oxide nanocrystals infivedifferent sizes: 5, 9,12,16, and 22 nm. In each batch, particle size variation was less than 4%, the team notes. In addition, the group demonstrated that particle size can be controlled at an even finer scale by varying reagent concentrations. T h e synthesis procedure is quite general, Hyeon remarks, and can be used to prepare nanocrystals of a variety of transitionmetal oxides. Furthermore, the procedure relies on nontoxic, inexpensive, and environmentally friendly reagents, he adds.—MITC H
coworkers at Sungkyunkwan Unitals can be prepared in large versity and Pohang University of batches through a new preScience & Technology paration method deTo prepare the veloped by researchnanocrystals, the reers in South Korea. searchers react metThe technique may al chlorides, such as hasten development FeCl 3 , with sodium of future nanotecholeate, which pronology applications duces a metal-oleate by providing a lowcomplex. Then when cost route to comthe material is heatmercial quantities of LOTS OF DOTS A ed slowly in a highuniform nanocrystals. false-color electron boiling-point solvent such as 1-octadecene, Researchers work- micrograph reveals the complexes deing in nanometer- the size uniformity compose and form scale science have in a batch of 12-nm nanocrystals. T h e demonstrated a vari- magnetite crystals. method was used to ety of devices that exprepare nanocrystals of MnO, ploit unique optical, electronic, CoO, 7-Fe 2 0 3 , M n F e 2 0 4 , and and other size-dependent propCoFe 2 0 4 . erties of nanocrystals. The key to capitalizing on those properties— On the basis of investigations for example, the unique color asconducted with transmission elecsociated with semiconductor tron microscopy, infrared specJAC0BY nanocrystals of a specific size that are suspended in a liquid—is limRESEARCH FUNDING iting variation in particle size. Several methods for preparing monodisperse nanocrystals have already been reported, but typically those he British government has committed methods yield much less than 1 g more than $200 million, to two programs ofproduct. that encourage new technologies. Now, scientists in South KoThe Department of Trade & Industry (DTI) is rea have shown that 40-g batchoffering roughly $150 million to British busies of uniform-sized magnetite nesses for research and development in emerg(Fe 3 04) nanocrystals and other ing sciences. Companies will be able to apply for materials can be prepared in a singrants to carry out collaborative R&D in nine gle reaction without a size-sorting different areas. Among them are micro- and step [Nat Mater., 3,891 (2004)}. nanotechnology, waste management and miniScaling up the process to produce mization, smart materials, biobased industrial multikilogram quantities is exproducts, and energy technologies. pected to be straightforward, the According to Trade & Industry Secretary Pascientists say tricia Hewitt, the investment "is vital support to The research team includes businesses to help take the new ideas and techTaeghwan Hyeon, a professor of nologies out of the lab and into the market. It is chemical engineering at Seoul not about picking 'winning companies'—it is National University graduate stuabout providing investment where there are dent Jongnam Park, and their clear gaps in the market. We want to kick-start
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THINK FLASK! Multigram quantities of uniform-sized nanocrystals are readily produced using a method developed by Hyeon (right) and Park, who is holding a flask containing magnetite nanoparticles dispersed in hexane.
U.K. Government Invests In New Technologies
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HTTP://WWW.CEN-ONLINE.ORG
R&D in these areas to ensure that the latest ideas and technologies can be turned into businesses, jobs, and prosperity." News of the DTI fund was followed quickly by the announcement of another pot of money, nearly $60 million, for an R&D network that supports composites technologies. The National Composites Network will have regional centers specializing in particular areas of composites technology. Industry Minister Jacqui Smith said she is counting on the network to help create and secure thousands of high-quality manufacturing jobs. The composites network is the first recipient of a new system of Knowledge Transfer Network grants announced by DTI in April. DTI launched a five-year program earlier this year called "Creating Wealth from Knowledge"; the funding projects are part of that program.-PATRICIA SHORT C&EN
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