Graphene quantum dots made from coal, introduced in 2013 by the Rice Univ. laboratory of chemist James Tour, can be engineered for specific semiconducting properties in either of two single-step processes. In a new study, Tour and colleagues demonstrated fine control over the graphene-oxide dots’ size-dependent band gap, the property that makes them semiconductors.
Researchers have fine-tuned a technique for coating gold nanorods with silica shells, allowing engineers to create large quantities of the nanorods and giving them more control over the thickness of the shell. Gold nanorods are being investigated for use in a wide variety of biomedical applications, and this advance paves the way for more stable gold nanorods and for chemically functionalizing the surface of the shells.
A new technique invented at Caltech to produce graphene at room temperature could help pave the way for commercially feasible graphene-based solar cells and LEDs, large-panel displays and flexible electronics. With the new technique, researchers can grow large sheets of electronic-grade graphene in much less time and at much lower temperatures.
The 3D printing revolution has changed the way we think about plastics. Everything from children’s toys to office supplies to high-value laboratory equipment can be printed. The potential savings of producing goods at the household- and lab-scale is remarkable, especially when producers use old prints and recycle them.
Winter storms dumped records amounts of snow on the East Coast this February, leaving treacherous, icy sidewalks and roads in their wake. Now researchers from Canada are developing new methods to mass-produce a material that may help pedestrians get a better grip on slippery surfaces. The material, which is made up of glass fibers embedded in a compliant rubber, could one day be used in the soles of slip-resistant winter boots.
An atomically thin membrane with microscopically small holes may prove to be the basis for future hydrogen fuel cells, water filtering and desalination membranes, according to a group of 15 theorists and experimentalists. The team tested the possibility of using graphene as a separation membrane in water and found that naturally occurring defects allowed hydrogen protons to cross the barrier at unprecedented speeds.
A team from Princeton Univ. and the Univ. of Florence in Italy has discovered a quasicrystal in a 4.5-billion-year-old meteorite from a remote region of northeastern Russia, bringing to two the number of natural quasicrystals ever discovered. Prior to the team finding the first natural quasicrystal in 2009, researchers thought that the structures were too fragile and energetically unstable to be formed by natural processes.
Two reports from Los Alamos National Laboratory in Scientific Reports are helping crack the code of how certain materials respond in the highly damaging radiation environments within a nuclear reactor. The goal of these efforts is to understand at an atomistic level just how materials develop defects during irradiation, and how those defects evolve to determine the ultimate fate of the material.
Research led by a Brown Univ. graduate student has revealed a new way to make light-absorbing perovskite films for use in solar cells. The new method involves a room-temperature solvent bath to create perovskite crystals, rather than the blast of heat used in current crystallization methods.
What lies beneath growing islands of graphene is important to its properties, according to a new study led by Rice Univ. Scientists at Rice analyzed patterns of graphene grown in a furnace via chemical vapor deposition. They discovered that the geometric relationship between graphene and the substrate, the underlying material on which carbon assembles atom by atom, determines how the island shapes emerge.
Mother-of-pearl, the iridescent layer in the shells of some mollusks, inspired a Rice Univ. study that will help scientists and engineers judge the ultimate strength, stiffness and toughness of composite materials for anything from nanoscale electronics to buildings.
Tiny glass nanospheres coated on one side with a very fine gold film: Ludwig Maximillian Univ. of Munich scientists have shown that particles modified in this way can be moved about with high precision using laser beams, creating an optically controlled micro-elevator.
Borrowing a trick from nature, engineers from the Univ. of California at Berkeley have created an incredibly thin, chameleon-like material that can be made to change color by simply applying a minute amount of force. This new material-of-many-colors offers intriguing possibilities for an entirely new class of display technologies, color-shifting camouflage and sensors.
Dental diseases, which are caused by the overgrowth of certain bacteria in the mouth, are among the most common health problems in the world. Now scientists have discovered that a material called graphene oxide is effective at eliminating these bacteria, some of which have developed antibiotic resistance. They report the findings in ACS Applied Materials & Interfaces.
Univ. of California, Berkeley chemists have made a major leap forward in carbon-capture technology with a material that can efficiently remove carbon from the ambient air of a submarine as readily as from the polluted emissions of a coal-fired power plant. The material then releases the carbon dioxide at lower temperatures than current carbon-capture materials.
Lithium-ion batteries have enabled many of today’s electronics, from portable gadgets to electric cars. But much to the frustration of consumers, none of these batteries last long without a recharge. Now scientists report in ACS Nano the development of a new, “green” way to boost the performance of these batteries: with a material derived from silk.
Caltech scientists, inspired by a chemical process found in leaves, have developed an electrically conductive film that could help pave the way for devices capable of harnessing sunlight to split water into hydrogen fuel. When applied to semiconducting materials such as silicon, the nickel oxide film prevents rust buildup and facilitates an important chemical process in the solar-driven production of fuels such as methane or hydrogen.
To fully understand how nanomaterials behave, one must also understand the atomic-scale deformation mechanisms that determine their structure and, therefore, their strength and function. Researchers have engineered a new way to observe and study these mechanisms and, in doing so, have revealed an interesting phenomenon in a well-known material, tungsten.
Most military battlefield casualties die before ever reaching a surgical hospital. Of those soldiers who might potentially survive, most die from uncontrolled bleeding. In some cases, there’s not much medics can do. That’s why Univ. of Washington researchers have developed a new injectable polymer that strengthens blood clots, called PolySTAT.
Researchers at the Univ. of California, Los Angeles and the Univ. Pierre et Marie Curie in Paris have identified a method for manufacturing longer-lasting and stronger forms of glass. The research could lead to more durable display screens, fiber-optic cables, windows and other materials, including cement.
With more than five times the thermal conductivity of copper, diamond is the ultimate heat spreader. But the slow rate of heat flow into diamond from other materials limits its use in practice. In particular, the physical process controlling heat flow between metals and diamond has remained a mystery to scientists for many years.
In nature, pores can continuously control how a living organism absorbs or excretes fluids, vapors and solids in response to its environment; for example, tiny holes invisible to the naked eye called stomata cover a plant's leaves and stems as gated openings through which oxygen, carbon dioxide and water vapors are transported in and out during photosynthesis and respiration.
Researchers have used an advanced model to simulate in unprecedented detail the workings of "resistance-switching cells" that might replace conventional memory for electronics applications, with the potential to bring faster and higher capacity computer memory while consuming less energy. These electromechanical "metallization cells" rapidly switch from high resistance to low resistance.
An extraordinary self-regulating heating effect that can be achieved in a particular type of magnetic material may open the doors to a new strategy for hyperthermia cancer treatment. Temperatures that can be tolerated by healthy body cells have long been known to destroy cancerous cells. An approach that uses magnetic particles introduced into tissue and heated remotely has found some success in treating cancer.
Tiny, perfectly smooth carbon spheres added to motor oil have been shown to reduce friction and wear typically seen in engines by as much as 25%, suggesting a similar enhancement in fuel economy. The researchers also have shown how to potentially mass-produce the spheres, making them hundreds of times faster than previously possible using ultrasound to speed chemical reactions in manufacturing.