Archive for the ‘materials’ category: Page 19

Dec 10, 2022

Scaling up the production of vertically aligned, single-walled carbon nanotubes

Posted by in categories: materials, nanotechnology

Lawrence Livermore National Laboratory (LLNL) scientists are scaling up the production of vertically aligned single-walled carbon nanotubes (SWCNT) that could revolutionize diverse commercial products ranging from rechargeable batteries, automotive parts and sporting goods to boat hulls and water filters. The research appears in the journal Carbon.

Most CNT production today is used in bulk composite materials and thin films, which rely on unorganized CNT architectures. For many uses, organized CNT architectures such as vertically aligned forests provide important advantages for exploiting the properties of individual CNTs in macroscopic systems.

“Robust synthesis of vertically-aligned carbon nanotubes at large scale is required to accelerate deployment of numerous cutting-edge devices to emerging ,” said LLNL scientist and lead author Francesco Fornasiero. “To address this need, we demonstrated that the structural characteristics of single-walled CNTs produced at wafer scale in a growth regime dominated by bulk diffusion of the gaseous carbon precursor are remarkably invariant over a broad range of process conditions.”

Dec 10, 2022

All types of plastics now recyclable thanks to two companies

Posted by in categories: materials, sustainability

This is number 22 on IE’s list of 22 best innovations, a look back at recycling for all plastics.

Two companies, Plastonix and Elemental Recycling have done what others could not: they have found technologies that recycle all types of plastic.

The monumental task of recycling the 380 million tons of plastic disposed of each year, that clog the ocean and beaches throughout the world, has eluded us. Around 80 percent of all plastic ends up in the oceans and landfills.

Continue reading “All types of plastics now recyclable thanks to two companies” »

Dec 10, 2022

New optical computing approach offers ultrafast processing

Posted by in categories: computing, materials

Logic gates are the fundamental components of computer processors. Conventional logic gates are electronic—they work by shuffling around electrons—but scientists have been developing light-based optical logic gates to meet the data processing and transfer demands of next-generation computing.

New optical chirality developed by researchers at Aalto University operate about a million times faster than existing technologies, offering ultrafast processing speeds.

The new approach uses circularly polarized light as the . The logic gates are made from crystalline materials that are sensitive to the handedness of a circularly polarized light beam—that is, the light emitted by the crystal depends on the handedness of the input beams. This serves as the basic building block for one type of logic gate (XNOR), and the remaining types of logic gates are built by adding filters or other optical components.

Dec 10, 2022

International research team creates previously unknown nitrogen compounds

Posted by in categories: chemistry, materials

Non-metal nitrides are compounds in which nitrogen and non-metallic elements are linked by covalent bonds. Because of their technologically interesting properties, they have increasingly become the focus of materials research. In Chemistry—A European Journal, an international team with researchers from the University of Bayreuth presents previously unknown phosphorus-nitrogen compounds synthesized under very high pressures.

They contain structural units whose existence could not be empirically proven before. The study exemplifies the great, as yet untapped potential of high-pressure research for nitrogen chemistry.

The researchers succeeded in synthesizing a previously unknown modification of the phosphorus nitride P₃N₅, the polymorph δ-P₃N₅, at a pressure of 72 gigapascals. At 134 gigapascals, the phosphorus nitride PN₂ formed in the diamond anvil cell. Both compounds are classified as ultra-incompressible materials with the bulk moduli above 320 GPa.

Dec 10, 2022

A novel sodium-sulphur battery has 4 times the capacity of lithium-ion batteries

Posted by in categories: materials, sustainability

The new sodium-sulfur batteries are also environmentally friendly, driving the clean energy mission forward at a low cost.

To realize the universal goal of net-zero emissions by 2050, the world is keenly looking at advancements in battery technology. Lower costs, higher capacity, and optimal utilization of scarce natural resources are expected to play a major role in taking the mission forward.

Their findings were published in Advanced Materials.

Continue reading “A novel sodium-sulphur battery has 4 times the capacity of lithium-ion batteries” »

Dec 9, 2022

Simple alloy claims crown of toughest material ever recorded

Posted by in category: materials

A simple alloy has claimed the crown for toughest material ever recorded. In a new study, a team led by researchers at Berkeley Lab ran the alloy through a series of tests and discovered not only its incredible toughness, but high strength and ductility that actually improve in colder temperatures, unlike most known materials.

The alloy in question contains chromium, cobalt and nickel (CrCoNi), and it belongs to a class of metals called high entropy alloys (HEAs). Most alloys are made up of one dominant element with smaller amounts of others added in, but HEAs contain equal amounts of each element. This can give them some impressive properties, such as high strength-to-weight ratios, an elastic modulus that rises with the temperature, or ultra strength and ductility.

In previous work, the researchers found that CrCoNi showed high strength and toughness at low temperatures of around −196 °C (−321 °F). For the new study, the team investigated how it would hold up at even colder temperatures of −253 °C (−424 °F), at which helium exists as a liquid. And sure enough, its toughness hit new heights in preventing cracks propagating.

Dec 7, 2022

Metal-to-Insulator Transition Similar to Water-to-Ice

Posted by in category: materials

A textbook theory for the freezing of water also explains the growth of a new phase in a more complicated phase transition of a different material.

When water freezes, the ice forms first in “nuclei”—tiny seed crystals that can grow or shrink and survive only if they reach a minimum size—at least according to the textbook theory. Researchers have now shown that this understanding also applies to a more complicated phase transition in vanadium dioxide (VO2), a material whose electrical properties and crystal structure both change at its so-called metal-to-insulator phase transition [1]. The team measured the threshold size for the “seeds” that drive this transition and demonstrated a new technique for studying crystal structure transitions. The result suggests that the classical nucleation theory is valid for a range of materials that are important in areas such as catalysis, lasers, and alloy and ceramic manufacturing.

Place a bucket of purified water in a subfreezing-temperature environment, and tiny ice seeds will start forming. Many will quickly dissolve, but those that are larger than a certain threshold size will grow and eventually merge to make a single block of ice. This view of crystallization, associated with classical nucleation theory, has been well accepted for the water–ice transition. Junqiao Wu of the University of California, Berkeley, and his colleagues wanted to test whether the same nucleation phenomenon is at play in VO2 when it makes a transition from one crystalline structure to another.

Dec 7, 2022

See The New Website That Simulates An Asteroid Strike In Your Hometown

Posted by in categories: materials, space

The asteroid strike simulation website lets users customize material, size, and speed then witness the destruction, in the name of science.

Dec 4, 2022

Intel Charts Course to Trillion-Transistor Chips: 2D Transistor Materials, 3D Packaging Research

Posted by in categories: computing, materials

Intel released nine research papers at IEDM 2022 that lay the groundwork for future chip designs as the company looks to deliver on its promise of developing processors with over a trillion transistors by 2030.

The research includes new 2D materials for transistors, new 3D packaging technology that narrows the performance and power gap between chiplet and single-die processors to a nearly-imperceptible range, transistors that ‘don’t forget’ when power is removed, and embedded memories that can be stacked directly on top of transistors and store more than one bit per cell, among other innovations.

Dec 4, 2022

Going back to basics yields a printable, transparent plastic that’s highly conductive

Posted by in category: materials

It was a simple idea—maybe even too simple to work.

Research scientist James Ponder and a team of Georgia Tech chemists and engineers thought they could design a transparent polymer film that would conduct electricity as effectively as other commonly used materials, while also being flexible and easy to use at an industrial scale.

They’d do it by simply removing the nonconductive material from their conductive element. Sounds logical, right?

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