Invisible Glass

If you have ever watched television in anything but total darkness, used a computer while sitting underneath overhead lighting or near a window, or taken a photo outside on a sunny day with your smartphone, you have experienced a major nuisance of modern display screens: glare. Most of today’s electronics devices are equipped with glass or plastic covers for protection against dust, moisture, and other environmental contaminants, but light reflection from these surfaces can make information displayed on the screens difficult to see. Now, scientists at the Center for Functional Nanomaterials (CFN) — a U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory — have demonstrated a method for reducing the surface reflections from glass surfaces to nearly zero by etching tiny nanoscale features into them.

Whenever light encounters an abrupt change in refractive index (how much a ray of light bends as it crosses from one material to another, such as between air and glass), a portion of the light is reflected. The nanoscale features have the effect of making the refractive index change gradually from that of air to that of glass, thereby avoiding reflections. The ultra-transparent nanotextured glass is antireflective over a broad wavelength range (the entire visible and near-infrared spectrum) and across a wide range of viewing angles. Reflections are reduced so much that the glass essentially becomes invisible.

This “invisible glass” could do more than improve the user experience for consumer electronic displays. It could enhance the energy-conversion efficiency of solar cells by minimizing the amount of sunlight lost to refection. It could also be a promising alternative to the damage-prone antireflective coatings conventionally used in lasers that emit powerful pulses of light, such as those applied to the manufacture of medical devices and aerospace components.

We’re excited about the possibilities,” said CFN Director Charles Black, corresponding author on the paper published online on October 30 in Applied Physics Letters. “Not only is the performance of these nanostructured materials extremely high, but we’re also implementing ideas from nanoscience in a manner that we believe is conducive to large-scale manufacturing.”

Our role in the CFN is to demonstrate how nanoscience can facilitate the design of new materials with improved properties,” concluded Black. “This work is a great example of that–we’d love to find a partner to help advance these remarkable materials toward technology.”

Source: https://www.eurekalert.org/

Spintronics

A team of scientists led by Associate Professor Yang Hyunsoo from the National University of Singapore’s (NUS) Faculty of Engineering has invented a novel ultra-thin multilayer film which could harness the properties of tiny magnetic whirls, known as skyrmions, as information carriers for storing and processing data (nanocomputer) on magnetic media. The nano-sized thin film, which was developed in collaboration with researchers from Brookhaven National Laboratory, Stony Brook University, and Louisiana State University, is a critical step towards the design of data storage devices that use less power and work faster than existing memory technologies.

The digital transformation has resulted in ever-increasing demands for better processing and storing of large amounts of data, as well as improvements in hard drive technology. Since their discovery in magnetic materials in 2009, skyrmions, which are tiny swirling magnetic textures only a few nanometres in size, have been extensively studied as possible information carriers in next-generation data storage and logic devices.

Skyrmions have been shown to exist in layered systems, with a heavy metal placed beneath a ferromagnetic material. Due to the interaction between the different materials, an interfacial symmetry breaking interaction, known as the Dzyaloshinskii-Moriya interaction (DMI), is formed, and this helps to stabilise a skyrmion. However, without an out-of-plane magnetic field present, the stability of the skyrmion is compromised. In addition, due to its tiny size, it is difficult to image the nano-sized materials. The NUS team found that a large DMI could be maintained in multilayer films composed of cobalt and palladium, and this is large enough to stabilise skyrmion spin textures.

skyrmionsThis experiment not only demonstrates the usefulness of L-TEM in studying these systems, but also opens up a completely new material in which skyrmions can be created. Without the need for a biasing field, the design and implementation of skyrmion based devices are significantly simplified. The small size of the skyrmions, combined with the incredible stability generated here, could be potentially useful for the design of next-generation spintronic devices that are energy efficient and can outperform current memory technologies,” explains Professor Yang .

The invention was reported in the journal Nature Communications.

Source: http://news.nus.edu.sg

How To Produce Massively And Easily Solar Panels

Nanoscale materials feature extraordinary, billionth-of-a-meter qualities that transform everything from energy generation to data storage. But while a nanostructured solar cell may be fantastically efficient, that precision is notoriously difficult to achieve on industrial scales. The solution may be self-assembly, or training molecules to stitch themselves together into high-performing configurations.

Now, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory have developed a laser-based technique to execute nanoscale self-assembly with unprecedented ease and efficiency.

solarPanelWe design materials that build themselves,” said Kevin Yager, a scientist at Brookhaven’s Center for Functional Nanomaterials (CFN). “Under the right conditions, molecules will naturally snap into a perfect configuration. The challenge is giving these nanomaterials the kick they need: the hotter they are, the faster they move around and settle into the desired formation. We used lasers to crank up the heat.”

Source: http://www.bnl.gov/

New Step Towards Massive Use Of Fuel Cells

Ulsan National Institute of Science and Technology (UNIST) -Korea -, Korea Institute of Energy Research (KIER), and Brookhaven National Laboratory, have discovered a new family of non-precious metal catalysts. These catalysts exhibit better performance than platinum in oxygen-reduction reaction (ORR) only with 10% of the production cost of a platinum catalyst.
The finding, described in Nature‘s Scientific Reports, provides an important step towards circumventing the biggest obstacle to widespread- commercialization of fuel cell technology.Fuel cells have various advantages compared to internal combustion engines or batteries, due to their high energy conversion efficiency and environmentally benign and quiet operation conditions. However, the high cost and instability of platinum catalysts for oxygen reduction reaction at the cathode have critically impeded the extensive application of polymer electrolyte fuel cells.

hydrogen-electric car

Currently the world is striving to look for another energy source for increased energy demand and environmental issue,” said Prof. Joo from UNIST. “The novel material developed by the UNIST research team would be a solution to commercialize the eco-friendly and cost-effective fuel cells.”

Our synthetic strategy for the non-precious metal catalysts included a multitude of advantages that would be favorable to PEFC applications” said Prof. Joo. “First, our synthetic method is amenable to simple and mild experimental conditions. Second, the synthesis of the M-OMPC catalysts could be readily scaled up to a few tens of grams in a single batch. Third, well-developed, hierarchical micro-mesoporosity would be advantageous for efficient transport of fuels and by-products. Finally, the M-OMPC catalysts showed very high surface areas, which could significantly increase the density of the catalytically active sites accessible to reactants.”

Source: http://www.unist.ac.kr/

Inexpensive Hydrogen For Electric Car

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have created a high-performing nanocatalyst with nanoparticles tolerant to carbon monoxide, a poisoning impurity in hydrogen derived from natural gas. The novel core-shell structure —< strong>ruthenium coated with platinum — resists damage from carbon monoxide as it drives the energetic reactions central to electric vehicle fuel cells and similar technologies. The quest to harness hydrogen as the clean-burning fuel of the future demands the perfect catalysts—nanoscale machines that enhance chemical reactions. Scientists must tweak atomic structures to achieve an optimum balance of reactivity, durability, and industrial-scale synthesis.

nanocrystals
These nanoparticles exhibit perfect atomic ordering in both the ruthenium and platinum, overcoming structural defects that previously crippled carbon monoxide-tolerant catalysts,” said study coauthor and Brookhaven Lab chemist Jia Wang. “Our highly scalable, ‘green’ synthesis method, as revealed by atomic-scale imaging techniques, opens new and exciting possibilities for catalysis and sustainability.”

The findings have been published in the online journal Nature Communications.
Source: http://www.bnl.gov/

Renewable Energy Fueled By Nature

Researchers at the U.S. Department of Energy’s Brookhaven National Laboratory describe details of a low-cost, stable, effective catalyst that could replace costly platinum in the production of hydrogen. The catalyst, made from renewable soybeans and abundant molybdenum metal, produces hydrogen in an environmentally friendly, cost-effective manner, potentially increasing the use of this clean energy source.
Their ultimate goal is to find ways to use solar energy — either directly or via electricity generated by solar cells — to convert the end products of hydrocarbon combustion, water and carbon dioxide, back into a carbon-based fuel. Dubbed “artificial photosynthesis,” this process mimics how plants convert those same ingredients to energy in the form of sugars. One key step is splitting water, or water electrolysis.
soybean-proteins

By splitting liquid water (H2O) into hydrogen and oxygen, the hydrogen can be regenerated as a gas (H2) and used directly as fuel,” explains Etsuko Sasaki, member of the Broohaven team.
“A very promising route to making a carbon-containing fuel is to hydrogenate carbon dioxide (or carbon monoxide) using solar-produced hydrogen,” adds Fujita, who leads the artificial photosynthesis group in the Brookhaven Chemistry Department.

Source: http://www.bnl.gov/

How to Draw Superior Images of Nanoparticles

A new x-ray imaging technique yields unprecedented measurements of nanoscale structures. Now, owing to a happy accident and subsequent insight, researchers at the US Department of Energy’s (DOE) Brookhaven National Laboratory have developed a new and strikingly simple x-ray scattering technique—detailed in the February issue of the Journal of Applied Crystallography—to help draw nanomaterials ranging from catalysts to proteins into greater focus.
x-ray beamThis rendering shows the high-intensity x-ray beam striking and then traveling through the gray sample material. In this new technique, the x-ray scattering—the blue and white ripples—is considerably less distorted than in other methods, producing superior images with less complex analysis.During an experiment, we noticed that one of the samples was misaligned,” said physicist Kevin Yager, a coauthor on the new study. “Our x-ray beam was hitting the edge, not the center as is typically desired. But when we saw how clean and undistorted the data was, we immediately realized that this could be a huge advantage in measuring nanostructures.

Source: http://www.bnl.gov/