Science Daily February 23, 2023 An international team of researchers (Israel, Japan) developed and demonstrated conceptually, a new type of tool — the quantum twisting microscope (QTM) — that could create novel quantum materials while simultaneously gazing into the most fundamental quantum nature of their electrons. It is capable of performing local interference experiments at its tip. The QTM is based on a unique van der Waals tip, allowing the creation of pristine two-dimensional junctions, which provide a multitude of coherently interfering paths for an electron to tunnel into a sample. With the addition of a continuously scanned twist angle […]
Tag Archives: Advanced materials
New corrosion protection that repairs itself
Phys.org February 21, 2023 An international team of researchers (Switzerland, Italy) has developed a plastic, Poly(phenylene methylene) PPM for short, that could greatly improve and simplify corrosion protection. When mixed as paint and heated, PPM can be sprayed onto a surface and becomes solid. The polymer indicates holes and cracks in the protective layer by failing to fluoresce and it repairs any damage itself without further external intervention and has high thermal stability. At the end of a product’s life, the polymer can be completely removed and recycled with only minimal material loss. The recycled polymer can then be applied […]
Researchers find thermal limits of advanced nanomaterials
Phys.org February 15, 2023 Boron nitride nanotubes (BNNTs), structural analogues to carbon nanotubes, are a strong candidate for nanofillers in high-temperature composites due to their high thermal stability, oxidation resistance, excellent mechanical properties, and high thermal conductivity. A team of researchers in the US (FAMU-FSU College of Engineering, industry) tested samples of high-quality, high-purity BNNTs in an inert atmosphere for thermal failure up to 2500 °C. A significant fraction of the BNNTs survived temperatures as high as 2200°, and the BNNT samples were completely undamaged at temperatures as high as 1800 °C. Boron nitride (BN) nanopowders were tested identically to […]
Solid material that ‘upconverts’ visible light photons to UV light photons could change how we utilize sunlight
Phys.org January 30, 2023 Only about 4% of terrestrial sunlight falls within the UV range in the electromagnetic spectrum. This leaves a large portion of sunlight spectrum unexploited for photopolymerization to form a resin and activation of photocatalysts to drive reactions that generate green hydrogen or useful hydrocarbons (fuels, sugars, olefins, etc.). Photon upconversion (UC) could be the key to solving this problem. Researchers in Japan have developed a revolutionary solid film that can perform visible-to-UV photon UC for weak incident light while remaining photostable for an unprecedented amount of time in air. The film is completely solvent-free “green” formation […]
GHz burst mode femtosecond laser pulses can create unique two-dimensional periodic surface nanostructures
Phys.org January 24, 2023 Most studies using the GHz burst mode femtosecond laser pulses focus on ablation of materials to achieve high-efficiency and high-quality material removal. Researchers in Japan explored the ability of the GHz burst mode femtosecond laser processing to form laser-induced periodic surface structures (LIPSS) on silicon. The direction of LIPSS formed by the single-pulse mode with linearly polarized laser pulses is typically perpendicular to the laser polarization direction. They showed that the GHz burst mode femtosecond laser created unique two-dimensional LIPSS. The team has proposed a possible mechanism for the formation of 2D LIPSS formed by the […]
Mathematics at the speed of light
Nanowerk January 16, 2023 Ultrathin optical metasurfaces have been recently explored to process large images in real time, in particular for edge detection. They can be tailored to solve complex mathematical problems in the analogue domain, although these efforts have so far been limited to guided-wave systems and bulky set-ups. An international team of researchers (the Netherlands, USA – University of Pennsylvania, City University of New York) developed an ultrathin Si metasurface-based platform for analogue computing that was able to solve Fredholm integral equations of the second kind using free-space visible radiation. A Si-based metagrating was inverse-designed to implement the […]
Organic semiconductors curl up in the dark
Nanowerk January 17, 2023 Organic semiconductors have the potential to replace their silicon predecessors in many applications. However, the manufacturing processes of solar cells that achieve such efficiencies are not yet compatible with mass production. An international team of researchers (Denmark, Germany) used roll-to-roll methos to print the organic semiconductor (poly(3-hexylthiophene) or P3HT), used for flexible solar cells, and organic electronics directly on a polymer film. In solution without illumination or under red light, the polymer chains quickly aggregated and formed ordered domains. When illuminated under green or blue light, the more rigid polymer chains, excited by the light, were […]
Discovery of a new form of carbon called long-range ordered porous carbon
Phys.org January 11, 2023 Carbon structures with covalent bonds connecting C60 molecules have been reported but until now there was no process to produce large enough quantities for detailed characterization and exploration necessary for potential applications. An international team of researchers (China, South Korea) has developed a gram-scale preparation method for long-range ordered porous carbon (LOPC), from C60 powder catalysed by α-Li3N at ambient pressure. LOPC consists of connected broken C60 cages that maintain long-range periodicity. At a lower temperature, shorter annealing time or by using less α-Li3N polymerized C60 crystal forms due to the electron transfer from α-Li3N to […]
‘Smart’ coating can be precisely applied to make fabric into protective gear
Science Daily January 9, 2023 Previously a team of researchers in the US (Dartmouth University, Maine University, DEVCOM Aberdeen Proving Ground) had developed conductive metal-organic technology (framework) which was a simple coating that could be layered onto cotton and polyester to create smart fabrics. In their current work, instead of the simple coating they precisely embedded the framework into fabrics using a copper precursor that allowed them to create specific patterns and more effectively fill in the tiny gaps and holes between threads. They found that the framework technology effectively converted the toxin nitric oxide into nitrite and nitrate, and […]
Researchers discover new process to create freestanding membranes of ‘smart’ materials
Phys.org January 3, 2023 The aggressive oxidizing conditions typically used in growing epitaxial oxides can damage graphene. A team of researchers in the US (University of Minnesota, Pacific Northwest National Laboratory, University of Wisconsin) used hybrid molecular beam epitaxy for SrTiO3 growth that did not require an independent oxygen source, thus avoided graphene damage. They produced epitaxial films with self-regulating cation stoichiometry. The film could be exfoliated and transferred to foreign substrates. The results opened the door to future studies of previously unattainable freestanding oxide nanomembranes grown in an adsorption-controlled manner by hybrid molecular beam epitaxy. According to the researchers […]