Imagine a tower that builds itself into the desired structure only by choosing the appropriate bricks. Absurd, but in the nano world self-assembly is now a common practice for forming structures. Researchers in Austria have been investigating how they can control the ordering of self-assembling structures and discovered how to switch the assembly process on and off.
Research published in the Proceedings of the National Academy of Sciences makes it possible to predict how subjecting metals to severe pressure can lower their electrical resistance, a finding that could have applications in computer chips and other materials that could benefit from specific electrical resistance.
Scientists have discovered a material that has the same extraordinary electronic properties as 2-D graphene, but in a sturdy 3-D form that should be much easier to shape into electronic devices such as very fast transistors, sensors and transparent electrodes. The material, cadmium arsenide, is being explored independently by three groups.
Thermal systems use heat to produce cold, and vice versa. The human body demonstrates this function when it perspires, but what is lacking for devices that operate on this principle are materials capable of sufficiently discharging the water vapor quickly. Metal organic frameworks (MOFs) are well suited to this task. Researchers have built a new 3-D porous MOF from metals and organic linkers that substantially increases water absorption.
Artificial joints have a limited lifespan. After a few years, many hip and knee joints have to be replaced. More problematic are intervertebral disc implants, which cannot easily be replaced after they “expire” and are usually reinforced, which restrict a patient’s movement. Researchers in Switzlernad have now succeeded in coating mobile intervertebral disc implants so that they show no wear and will now last for a lifetime.
By levitating a bead of ceramic oxide, heating it with a 400-W carbon dioxide laser, then shooting the molten material with x-rays and neutrons, scientists with Oak Ridge and Argonne national laboratories have revealed unprecedented detail of the structure of high-temperature liquid oxides.
Nanotubes have been the subject of intensive research, with potential uses ranging from solar cells to chemical sensors to reinforced composite materials. Most of the research has centered on carbon nanotubes, but other nanotubes’ properties appear to be similar. However, appearances can be deceiving, as researchers have found when examining one variant of nanotube made from boron nitride.
Imperfections in the regular atomic arrangements in crystals determine many of the properties of a material, and their diffusion is behind many microstructural changes in solids. However, imaging non-repeating atomic arrangements is difficult in conventional materials. Now, researchers in Austria have directly imaged the diffusion of a butterfly-shaped atomic defect in graphene.
Bang & Olufsen is working with scientists in Denmark to develop a method for creating white aluminium surfaces. This has been exceedingly difficult for manufacturers because the existing technology used to color aluminium cannot be used to produce the color white because the molecules used to create “white” are too big. Rather than use pigments, then, researchers have a way to make it become white during the process.
In the wake of recent offshore oil spills, and with the growing popularity of “fracking”—in which water is used to release oil and gas from shale—there’s a need for easy, quick ways to separate oil and water. Now, scientists have developed coatings that can do just that. Their report on the materials, which also could stop surfaces from getting foggy and dirty, appears in ACS Applied Materials & Interfaces.
A team at Lawrence Berkeley National Laboratory found unexpected traces of water in semiconducting nanocrystals. The water as a source of small ions for the surface of colloidal lead sulfide nanoparticles allowed the team to explain just how the surface of these important particles are passivated, meaning how they achieve an overall balance of positive and negative ions.
A team of researchers has successfully tracked single molecules inside living cells with carbon nanotubes. Through this new method, the researchers found that cells stir their interiors using the same motor proteins that serve in muscle contraction. The study, which sheds new light on biological transport mechanisms in cells, appears in Science.
When crude oil is refined to fuels and chemicals, catalysts such as zeolites. are at work making this process happen. Scientists have recently developed a reference parameter for the performance of this important class of catalysts, which can suffer from production hindrances if reaction side products clog pores or block active sites on the catalyst.
Batteries don’t age gracefully. The lithium ions that power portable electronics cause lingering structural damage with each cycle of charge and discharge, making devices from smartphones to tablets tick toward zero faster and faster over time. To stop or slow this steady degradation, scientists must track and tweak the imperfect chemistry of lithium-ion batteries with nanoscale precision.
In order to see the true polarization of ferroelectric materials quickly and efficiently, researchers at Argonne National Laboratory have developed a new technique called charge gradient microscopy. Charge gradient microscopy uses the tip of a conventional atomic force microscope to scrape and collect the surface screen charges.
In recent research in Germany, the desorption of oxygen molecules from a silver surface was successfully visualized for the first time using low-energy electron microscopy. The effects account for the shortcomings of conventional models of desorption, which often deliver rates that do not agree with experimentally determined values.
Using a doped-graphene matrix to slow down and then trap atoms of the precious metal osmium, researchers in the U.K. have shown the ability to control and quantify the growth of metal-crystals. When the trapped atoms come into contact with further osmium atoms they bind together, eventually growing into 3-D metal-crystals. They have called this new technique nanocrystallometry.
Solar cell technology has advanced rapidly, as hundreds of groups around the world pursue more than two dozen approaches using different materials, technologies and approaches to improve efficiency and reduce costs. Now a team at Massachusetts Institute of Technology has set a new record for the most efficient quantum-dot cells.
Soon after graphene’s isolation, early research already showed that lithium batteries with graphene in their electrodes had a greater capacity and lifespan than standard designs. At the Univ. of Manchester, U.K., where graphene was first isolated, researchers are working with more than 30 companies to advance technology in graphene-enabled energy storage, particularly in the area of lithium-ion batteries and supercapacitors.
They are 3-D and yet single-sided: Moebius strips. These twisted objects have only one side and one edge. Using this iconic form, an international team of scientists has succeeded in designing the world’s first “triply” twisted molecule. Because of their peculiar quantum mechanical properties these structures are interesting for applications in molecular electronics and optoelectronics.
Fancy Erector Set? Nope. The elaborate fractal structure shown at left is many, many times smaller than that and is certainly not child's play. It’s the latest example of a fractal nanotruss—nano because the structures are made up of members that are as thin as 5 nm; truss because they are carefully architected structures that might one day be used in structural engineering materials.
Researchers in Spain have introduced a platform technology based on optical antennas for trapping and controlling light with graphene. Their experiments show that the dramatically squeezed graphene-guided light can be focused and bent, following the fundamental principles of conventional optics. The work opens new opportunities for smaller and faster photonic devices and circuits.
In response to requests from the semiconductor industry, a team of researchers at the Physical Measurement Laboratory has demonstrated that atomic force microscope probe tips made from its near-perfect gallium nitride nanowires are superior in many respects to standard silicon or platinum tips. They also found a way to use the tips as LEDs to illuminate sample regions while scanning.
Scientists at the U.S. Dept. of Energy’s Argonne National Laboratory have discovered a previously unknown phase in a class of superconductors called iron arsenides. This sheds light on a debate over the interactions between atoms and electrons that are responsible for their unusual superconductivity.
Images taken by Rice Univ. scientists show that some diamonds are not forever. The Rice researchers behind a new study that explains the creation of nanodiamonds in treated coal also show that some microscopic diamonds only last seconds before fading back into less-structured forms of carbon under the impact of an electron beam.