Published on April 29th, 2014 | By: April Gocha, PhD0
Other materials stories that may be of interestPublished on April 29th, 2014 | By: April Gocha, PhD
Americans generate nearly 300 million scrap tires every year, according to the Environmental Protection Agency (EPA). Historically, these worn tires often end up in landfills or, when illegally dumped, become breeding grounds for disease-carrying mosquitoes and rodents. They also pose a potential fire hazard. In recent years, however, interest has been growing in finding new, beneficial and environmentally friendly uses for discarded tires. Magdy Abdelrahman, for example, an associate professor of civil and environmental engineering at North Dakota State University, is working on ways to turn old tires into new and improved roads. The National Science Foundation (NSF)-funded scientist is experimenting with “crumb” rubber—ground up tires of different sized particles—and other components to improve the rubberized road materials that a number of states already are using to enhance aging asphalt.
By combining the powers of two single-atom-thick carbon structures, researchers at the George Washington University’s Micro-propulsion and Nanotechnology Laboratory have created a new ultracapacitor that is both high performance and low cost. The device, described in the Journal of Applied Physics, capitalizes on the synergy brought by mixing graphene flakes with single-walled carbon nanotubes, two carbon nanostructures with complementary properties. Ultracapacitors are souped-up energy storage devices that hold high amounts of energy and can also quickly release that energy in a surge of power. By combining the high energy-density properties of batteries with the high power-density properties of conventional capacitors, ultracapacitors can boost the performance of electric vehicles, handheld electronics, audio systems and more.
In research recently published in the journal ACS Nano, a team of scientists from École Polytechnique Fédérale de Lausanne have demonstrated the possibility of creating light-emitting diodes and solar cells from molybdenite. The scientists built several prototypes of diodes made up of a layer of molybdenite superposed on a layer of silicon. At the interface, each electron emitted by the MoS2 combines with a “hole”—a space left vacant by an electron—in the silicon. The two elements lose their respective energies, which then transforms into photons. “This light production is caused by the specific properties of molybdenite,” explains one of the authors. “Other semi-conductors would tend to transform this energy into heat.”
(Phys.org) Washing a car can be a chore—and a costly one at that. In response, Nissan in Europe has begun tests on innovative paint technology that repels mud, rain and everyday dirt, meaning drivers may never have to clean their car again. The specially engineered super-hydrophobic and oleophobic paint, which repels water and oils, has been applied to the all-new European market Nissan Note to create the world’s first self-cleaning car. Nissan is the first carmaker to apply the technology, called Ultra-Ever Dry, on automotive bodywork. By creating a protective layer of air between the paint and environment, it effectively stops standing water and road spray from creating dirty marks on the car’s surface.
The ability to control crystals with light and chemistry could lead to chameleon-style color-changing camouflage for vehicle bodies and other surfaces. University of Michigan researchers discovered a template-free method for growing shaped crystals that allows for changeable structures that could appear as different colors and patterns. One source of color in crystal structures is the spacing between the particles that make up the crystal. The spacing can determine which colors of light the crystal absorbs and which it reflects, resulting in the visible color. By changing the spacing and other aspects of the crystal structure, it is possible to change the color. The researchers have found a way to control a crystal on the fly as it forms in a solution of latex paint microparticles, around 0.001 millimeters in diameter, in a kerosene-like fluid.
A Rice University laboratory has flexible, portable, and wearable electronics in its sights with the creation of a thin film for energy storage. Rice chemist James Tour and his colleagues have developed a flexible material with nanoporous nickel-fluoride electrodes layered around a solid electrolyte to deliver battery-like supercapacitor performance that combines the best qualities of a high-energy battery and a high-powered supercapacitor without the lithium found in commercial batteries today. Their electrochemical capacitor is about a hundredth of an inch thick but can be scaled up for devices either by increasing the size or adding layers. In tests, the square-inch device held 76 percent of its capacity over 10,000 charge-discharge cycles and 1,000 bending cycles.
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