Other materials science stories that may be of interestPublished on October 1st, 2012 | By: firstname.lastname@example.org
You probably already know there is some really interesting stuff going on in the materials field. Here is some of the latest:
A project in Europe aims to convert urban and agricultural waste into high-performance products for the construction sector. These materials will be developed within the framework of INNOBITE (Innovative Biocomposites), a European Commission FP7 collaborative project co-participated by several research centers and European small and medium-sized enterprises, including the UK’s Exergy. According to a statement, the research, led by Spain’s Tecnalia, is based on two ideas: the revalorisation of the inorganic fraction of wheat straw and the production of cellulose nanofibers out of recycled paper. Once isolated, these two compounds will become high-performance additives in new polymeric composites. The two most abundant fractions of wheat straw—lignin and cellulose—will become, respectively, polymeric matrix and reinforcing material.
(Lux Research) Toyota has triggered electric vehicle alarmism by announcing it will lower sales targets of its iQ EV hatchback to just 100 units of this all-electric vehicle. The news came accompanied by some damning quotes, with Toyota head of vehicle development Takeshi Uchiyamada opining that the “capabilities of electric vehicles do not meet society’s needs.” Many have been quick to misinterpret this as a new development—an unexpected vote of no confidence in EVs. However, the reality is that Toyota has never pursued all-electric vehicles in earnest. While competitors were developing cars like the Nissan Leaf EV and Chevrolet Volt heavy plug-in hybrid, Toyota instead opted to focus on more incremental hybrid electric vehicles and development of a light PHEV with a much smaller battery. It worked— the company hit a 2-million-unit home run with its Prius line of hybrids that now includes a light PHEV. Lux Research predicted this EV disappointment three years ago in the report “Unplugging the Hype Around Electric Vehicles and has held steady in that view. The reality is that HEVs and light PHEVs are simply far more economical now, given high battery costs, and will remain so for years to come. As a result, in 2020 sales of HEVs and light PHEVs will be 16 times greater than those of heavy PHEVs and EVs. The announcement also reinforces that the world’s largest carmaker’s strategy is a rebuke to the investment by the US and other governments in EVs and subsidies. The political fallout could be severe, especially following flops like Solyndra in other areas. Companies can find strong opportunities in battery advances for light PHEVs and hybrids, as well as micro- and mild hybrids, but should remain cautious about the electric vehicle opportunity.
The University of Arizona College of Engineering will lead a $5.5 million, 5-year research project, funded by the DOE, to develop more affordable and efficient concentrated solar power systems. The research program will investigate the composition, properties and costs of new molten-salt-based CSP heat transfer fluids, which must absorb, transport and store solar energy, and generate electrical power efficiently and cost-effectively. To overcome the nocturnal drop in power generation capability, an objective of this research is to develop molten-salt-based CSP heat transfer fluids with low melting points and low corrosivity that can be heated to about 2,400 degrees Fahrenheit. Temperatures thus have much further to fall before the transfer fluid cools and solidifies. Insulating the fluid storage tanks and circulation system will enable the stored heat to generate steam, and electrical power, throughout the night. The salts used in current CSP plants are nitrates, which can operate at a maximum of about 1,000°F before they become unstable, says Peiwen “Perry” Li. “This is not efficient enough, and this research has a requirement to find a salt that reaches about 1,500°F,” Li says. “But if we can stretch to 2,400°F, that will be super.” The current objective for this project is a molten salt that costs less than a dollar per kilo.
Steven A. Klankowski, a doctoral candidate in chemistry, La Crescent, Minn., is working under Jun Li, professor of chemistry, to develop new materials that could be used in future lithium-ion batteries. For his research, Klankowski is developing and testing a high-performance nanostructure of silicon coated onto carbon nanofibers for the use as an electrode in lithium-ion batteries. The electrodes, which look like a dense brush, give the battery greater charge capabilities and storage capacity. This is anticipated to replace current commercial electrodes that are made from simple carbon-based materials. The material being developed and improved by Klankowski helps the electrode store roughly 10 times the amount of energy as current electrodes, giving the batteries a 10-15 percent improvement in current battery technology. “We’re trying to go for higher energy capacity,” Klankowski says. “To do that we’re looking at if we can store more energy per the electrode’s size or mass, and if we can use that energy more quickly to make the battery like a capacitor. Batteries and capacitors are on opposite sides of the energy storage field. We’d like to move them both closer together.”
An international research team has created unique photoluminescent nanoparticles that shine clearly through more than 3 centimeters of biological tissue—a depth that makes them a promising tool for deep-tissue optical bioimaging. Though optical imaging is a robust and inexpensive technique commonly used in biomedical applications, current technologies lack the ability to look deep into tissue, the researchers said. This creates a demand for the development of new approaches that provide high-resolution, high-contrast optical bioimaging that doctors and scientists could use to identify tumors or other anomalies deep beneath the skin. The newly created nanoparticles consist of a nanocrystalline core containing thulium, sodium, ytterbium and fluorine, all encased inside a square, calcium-fluoride shell. The particles are special for several reasons. First, they absorb and emit near-infrared light, with the emitted light having a much shorter wavelength than the absorbed light. This is different from how molecules in biological tissues absorb and emit light, which means that scientists can use the particles to obtain deeper, higher-contrast imaging than traditional fluorescence-based techniques. Second, the material for the nanoparticles’ shell—calcium fluoride—is a substance found in bone and tooth mineral. This makes the particles compatible with human biology, reducing the risk of adverse effects. The shell is also found to significantly increase the photoluminescence efficiency. To emit light, the particles employ a process called near-infrared-to-near-infrared up-conversion, or “NIR-to-NIR.”
(The Engineer) An engineer and a fashion designer have developed a way to make clothes that can clean the air using a special laundry additive. The liquid additive known as CatClo (Catalytic Clothing) adds nanoparticles of titanium oxide to the fabric of clothing. When exposed to sunlight, these particles react with nitrogen oxides in the air and oxidise them into the fabric. The treated pollutants are odourless and colourless and are removed harmlessly as the wearer sweats or when the clothes are next washed, but the catalytic nanoparticles remain because they grip the fabric so tightly. One person wearing clothes treated with CatClo would remove an average of 5g of nitrogen oxides from the air each day, roughly equivalent to the amount produced by the average family car, according to its developers. “If thousands of people in a typical town used the additive, the result would be a significant improvement in local air quality,” says Prof Tony Ryan of Sheffield University, who developed the additive with Prof Helen Storey of the London College of Fashion. “This additive creates the potential for community action to deliver a real environmental benefit that could actually help to cut disease and save lives. In Sheffield, for instance, if everyone washed their clothes in the additive, there would be no pollution problem caused by nitrogen oxides at all.” The team is now working with a manufacturer of environmentally friendly cleaning products to commercialise the additive, he adds.
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