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 […]

Novel nanowire fabrication technique paves way for next generation spintronics

Nanowerk  November 9, 2022 Eliminating the etching process by directly fabricating nanowires onto the silicon substrate would lead to a marked improvement in the fabrication of spintronic devices. However, when directly fabricated nanowires are subjected to annealing, they tend to transform into droplets as a result of the internal stresses in the wire. Researchers in Japan have developed a new fabrication process to make L10-ordered CoPt nanowires on silicon/silicon dioxide (Si/SiO2) substrates. They coated a Si/SiO2 substrate with a material called a ‘resist’ and subjected it to electron beam lithography and evaporation to create a stencil for the nanowires, deposited […]

Nanomaterials: Light dependent atom clusters for sensing applications

Phys.org  April 1, 2022 An international team of researchers (Japan, France, Germany, Switzerland) has developed a new environment-sensing device based on the opto-ionic-electronic phenomena of an octahedral molybdenum metal (Mo6) cluster. When the Mo6 cluster is electrochemically deposited on a transparent electrode in an organic solvent containing a trace amount of water, the water permeates the deposited film. During the process, some ligand species that stabilize the frame structure of the Mo6 cluster are substituted with hydroxyl groups, and the negatively charged frame structure of the Mo6 cluster unit is stabilized by hydronium counterions. As a result, the transparent film […]

New material could mean lightweight armor, protective coatings

Science Daily  July 19, 2021 An international team of researchers (USA – MIT, Caltech, Switzerland) has fabricated nanoarchitectured materials, that absorb the impact of microscopic projectiles accelerated to supersonic speeds. According to their calculations the new material absorbs impacts more efficiently than steel, Kevlar, aluminum, and other impact-resistant materials of comparable weight. Tests revealed that consistent mechanisms such as compaction cratering and microparticle capture enable this superior response. They introduced predictive tools for crater formation in these materials using dimensional analysis. These results substantially uncover the dynamic regime over which nanoarchitecture enables the design of ultralightweight, impact-resistant materials that could […]

Creating nanomaterials with new laser driven method

Nanowerk  May 31, 2021 For successful implementation of photoelectrocatalytic synthesis of fuels and value-added chemicals hybrid photoelectrodes with low energy consumption and high photocurrent densities are essential. Researchers in Japan have developed a laser-driven technology to print sensitizers with desired morphologies and layer thickness onto different substrates, such as glass, carbon, or carbon nitride (CN). The process uses a thin polymer reactor impregnated with transition metal salts, confining the growth of TMO nanostructures on the interface in milliseconds, while their morphology can be tuned by the laser. Multiple nano-p-n junctions at the interface increase the electron/hole lifetime by efficient charge […]

Nanosheet-based electronics could be one drop away

Nanowerk  January 8, 2021 Researchers in Japan overcame the “coffee ring” effect of drop casting by controlled convection using a pipette and a hotplate. They found that dropping a solution containing 2D nanosheets with a simple pipette onto a substrate heated on a hotplate to a temperature of about 100°C, followed by removal of the solution, causes the nanosheets to come together in about 30 seconds to form a tile-like layer. They demonstrated controlled thermal convection by depositing particle solutions of titanium dioxide, calcium niobate, ruthenium oxide, and graphene oxide. They also tried different sizes and shapes of a variety […]

Intelligent nanomaterials for photonics

Science Daily  October 7, 2020 2D materials – combined with optical fibers – can enable novel applications in the areas of sensors, non-linear optics, and quantum technologies. An international team of researchers (Germany, Australia) studied the chemical vapor deposition of monolayer MoS2 and WS2 crystals on the core of microstructured exposed‐core optical fibers and their interaction with the fibers’ guided modes. Two distinct application possibilities of 2D‐functionalized waveguides to exemplify their potential are demonstrated. First, the excitonic 2D material photoluminescence is simultaneously excited and collected with the fiber modes. Then it is shown that third‐harmonic generation is modified by the highly […]

Harvesting hydrogen from nanogardens

Nanowerk  July 3, 2020 By manipulating (electro)chemical gradients using a combined hydrothermal and electrodeposition strategy, an international team of researchers (China, the Netherlands) has shown the controlled growth of Co(OH)2 nanostructures, mimicking the process of garden cultivation. The resulting “nano-garden” can selectively contain different patterns, all of which can be fully phosphidated into CoP without losing the structural integrity. Under pH-universal conditions, the CoP “soil + flower-with-stem” structure shows a much more “effective” surface area for gas-evolving reactions with lower activation and concentration overpotentials. This provides superior bifunctional catalytic activity for both reactions, outperforming noble metal counterparts…read more. Open Access […]

Computer program can translate a free-form 2-D drawing into a DNA structure

Phys.org  January 3, 2019 Scaffolded DNA origami offers the unique ability to organize molecules in nearly arbitrary spatial patterns at the nanometer scale, with wireframe designs further enabling complex 2D and 3D geometries with irregular boundaries and internal structures. A team of researchers in the US (MIT, Arizona State University) has developed a fully autonomous procedure to design all DNA staple sequences needed to fold any free-form 2D scaffolded DNA origami wireframe object. The algorithm enables the full autonomy of scaffold routing and staple sequence design with arbitrary network edge lengths and vertex angles. The technique has utility for nanoscale […]

New megalibrary approach proves useful for the rapid discovery of new nanomaterials

Nanowerk  December 18, 2018 A team of researchers in the US (Northwestern University, AFRL at Wright-Patterson AFB) supports the efficacy of a potentially revolutionary new tool developed at Northwestern University to rapidly test millions (even billions) of nanoparticles to determine the best one for a specific use. The tool utilizes a combinatorial library, or megalibrary, of nanoparticles in a very controlled way. The libraries are created using Mirkin’s Polymer Pen Lithography (PPL) technique, which relies on arrays with hundreds of thousands of pyramidal tips to deposit individual polymer “dots” of various sizes and composition, each loaded with different metal salts […]