Innovative nanosheets made from equal parts of hydrogen and boron have a greater capacity to store and release hydrogen compared with conventional metal-based materials.
Category: materials – Page 270
“Unsinkable metal” stays afloat even with holes punched in it
Superhydrophobic materials, which are excellent at repelling water, can be extremely useful for a whole range of reasons, both obvious and not-so-obvious. They can prevent ice from building up on surfaces, make electronics waterproof, make ships more efficient or keep people from peeing in public. Now engineers have found a quirky new use for superhydrophobic materials – making “unsinkable” metals that stay floating even when punctured.
Superhydrophobic materials get their water-repelling properties by trapping air in complex surfaces. These air bubbles make it hard for water to stick, so droplets instead bounce or roll right off. But, of course, air also makes things buoyant, so the team set out to test how superhydrophobic materials could be used to make objects that float better.
The researchers used ultra-fast laser pulses to etch microscale and nanoscale patterns onto the surfaces. That traps large volumes of air, making the metals both superhydrophobic and buoyant. But the problem was that these complex surfaces would eventually wear away due to friction in the water, reducing the effectiveness of both of those properties.
Simulated sunlight reveals how 98% of plastics at sea go missing each year
Trillions of plastic fragments are afloat at sea, which cause large “garbage patches” to form in rotating ocean currents called subtropical gyres. As a result, impacts on ocean life are increasing and affecting organisms from large mammals to bacteria at the base of the ocean food web. Despite this immense accumulation of plastics at sea, it only accounts for 1 to 2 percent of plastic debris inputs to the ocean. The fate of this missing plastic and its impact on marine life remains largely unknown.
It appears that sunlight-driven photoreactions could be an important sink of buoyant plastics at sea. Sunlight also may have a role in reducing plastics to sizes below those captured by oceanic studies. This theory could partly explain how more than 98 percent of the plastics entering the oceans go missing every year. However, direct, experimental evidence for the photochemical degradation of marine plastics remains rare.
A team of scientists from Florida Atlantic University’s Harbor Branch Oceanographic Institute, East China Normal University and Northeastern University conducted a unique study to help elucidate the mystery of missing plastic fragments at sea. Their work provides novel insight regarding the removal mechanisms and potential lifetimes of a select few microplastics.
Suspended layers make a special superconductor
In superconducting materials, an electric current will flow without any resistance. There are quite a few practical applications of this phenomenon; however, many fundamental questions remain as yet unanswered. Associate Professor Justin Ye, head of the Device Physics of Complex Materials group at the University of Groningen, studied superconductivity in a double layer of molybdenum disulfide and discovered new superconducting states. The results were published in the journal Nature Nanotechnology on 4 November.
Superconductivity has been shown in monolayer crystals of, for example, molybdenum disulphide or tungsten disulfide that have a thickness of just three atoms. “In both monolayers, there is a special type of superconductivity in which an internal magnetic field protects the superconducting state from external magnetic fields,” Ye explains. Normal superconductivity disappears when a large external magnetic field is applied, but this Ising superconductivity is strongly protected. Even in the strongest static magnetic field in Europe, which has a strength of 37 Tesla, the superconductivity in tungsten disulfide does not show any change. However, although it is great to have such strong protection, the next challenge is to find a way to control this protective effect, by applying an electric field.
Northrop successfully launches Cygnus cargo spacecraft for the ISS
An Antares rocket from Northrop Grumman has successfully launched the Cygnus cargo spacecraft on its way to the International Space Station. The launch happened at 9:59AM from the Mid Atlantic Regional Spaceport as anticipated. Assuming nothing unusual happens, NASA says the cargo vessel will arrive at the ISS on Monday, November 4, carrying a huge load of supplies and scientific materials.
Japan proposes wooden cars made of plant-based cellulose nanofibers
One-fifth the weight of steel but five times the strength, plant-based cellulose nanofiber (CNF) offers carmakers the opportunity to build strong, lightweight cars while sustainably removing as much as 2,000 kg (4,400 lb) of carbon from the car’s life cycle.
We’ve written before about the extraordinary properties of CNFs, which were last year demonstrated to be stronger than spider silk. Made essentially from wood, but chipped, pulped and boiled in chemicals to remove lignin and hemicellulose, it’s a highly condensed, lightweight and incredibly strong material that’s also very recyclable.
It can also, as it turns out, be used in manufacturing, where it can be injection molded as a resin-reinforced slurry to form complex shapes – and the Japanese Ministry of the Environment sees it as a potential way for automakers to reduce weight and sustainably reduce their carbon footprint.
Rocket Report: Would you buy Virgin Galactic stock? Rocket Lab goes lunar
Potential for small science missions … “Small satellites will play a crucial role in science and exploration, as well as providing communications and navigation infrastructure to support returning humans to the Moon,” Rocket Lab head honcho Peter Beck said. “They play a vital role as pathfinders to retire risk and lay down infrastructure for future missions. We think this could be useful for CubeSat science around the Moon or possibly communications relay capability on the cheap.” (submitted by 3ch0 and ADU)
Firefly considering AR1 engine for its Beta rocket. Firefly Aerospace has said it is collaborating with engine-maker Aerojet Rocketdyne to increase the performance of its upcoming Alpha launch vehicle, and the company is also considering Aerojet Rocketdyne’s AR1 engine for a future launch vehicle, SpaceNews reports. In a statement, Firefly CEO Tom Markusic praised the AR1 as an engine well suited for Beta but stopped short of saying the engine’s selection is a done deal.
How far along is AR1 really? … Markusic: “Aerojet Rocketdyne’s AR1 engine, which incorporates the latest advances in propulsion technology, materials science, and manufacturing techniques, is incredibly well-suited to power Beta given its cost-effective, high-performance capabilities.” It is not at all clear to us how close Aerojet is to completing and qualifying the AR1 engine. It also seems like Firefly should get Alpha up and running before it worries too much about the larger Beta rocket. (submitted by Unrulycow)