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 […]
Tag Archives: Materials science
Can clay capture carbon dioxide?
Phys.org February 9, 2023 Although numerous investigations have studied the formation of H2CO3 in water from CO2, the conversion of CO2 to H2CO3 in nanopores, and how it differs from that in bulk water, has not been understood. Researchers at Sandia National Laboratory used ReaxFF metadynamics molecular simulations to demonstrate striking differences in the free energy of CO2 conversion to H2CO3 in bulk and nanoconfined aqueous environments. They found that nanoconfinement not only reduces the energy barrier but also reverses the reaction from endothermic in bulk water to exothermic in nanoconfined water. Charged intermediates are observed more often under nanoconfinement […]
A counterintuitive way to make stronger alloys
Phys.org February 9, 2023 Low-temperature decomposition of supersaturated solid solution into unfavorable intergranular precipitates is a long-standing bottleneck limiting the practical applications of nanograined aluminum alloys that are prepared by severe plastic deformation. Minimizing the vacancy concentration is generally regarded as an effective approach in suppressing the decomposition process. An international team of researchers (China, Norway, Italy) has developed a strategy to stabilize supersaturated solid solution in nanograined Al-Cu alloys via high-density vacancies in combination with Sc microalloying. By generating a two orders of magnitude higher concentration of vacancies bonded in strong (Cu, Sc, vacancy)-rich atomic complexes, a high thermal […]
Scientists open new window on the physics of glass formation
Phys.org January 24, 2023 A common feature of glasses is the “boson peak”, observed as an excess in the heat capacity over the crystal or as an additional peak in the terahertz vibrational spectrum. The microscopic origins of this peak are not well understood; the emergence of locally ordered structures has been put forward as a possible candidate. An international team of researchers (UK, Slovenia, Japan) has shown that depolarised Raman scattering in liquids consisting of highly symmetric molecules can be used to isolate the boson peak, allowing its detailed observation from the liquid into the glass. The boson peak […]
MIT engineers grow “perfect” atom-thin materials on industrial silicon wafers
MIT News January 18, 2023 Two-dimensional materials and their heterostructures show a promising path for next-generation electronics. Nevertheless, 2D-based electronics have not been commercialized, owing mainly to three critical challenges: i) precise kinetic control of layer-by-layer 2D material growth, ii) maintaining a single domain during the growth, and iii) wafer-scale controllability of layer numbers and crystallinity. An international team of researchers (USA – MIT, UT Dallas, UC Riverside, Washington University, South Korea) has introduced a deterministic, confined-growth technique that can tackle these three issues simultaneously, thus obtaining wafer-scale single-domain 2D monolayer arrays and their heterostructures on arbitrary substrates. They geometrically confined the […]
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 […]
Solids that are also liquids: Elastic tensors of superionic material
Phys.org January 30, 2023 Superionics display both solid- and liquid-like characteristics: as solids, they respond elastically to shear stress; as liquids, they display fast-ion diffusion at normal conditions. They are technologically relevant for energy, electronics, and sensing applications. Characterizing and understanding their elastic properties are needed to address their feasibility as solid-state electrolytes in all-solid-state batteries. However, static approaches to elasticity assume well-defined reference positions around which atoms vibrate, in contrast with the quasi-liquid motion of the mobile ions in fast ionic conductors. Researchers in Switzerland have derived the elastic tensors of superionics from ensemble fluctuations in the isobaric-isothermal ensemble, exploiting extensive Car-Parrinello simulations. They applied this approach to […]
Lightning Strikes Create a Strange Form of Crystal Rarely Seen in Nature
Science Alert January 30, 2023 An international team of researchers (Italy, University of South Florida, Caltech, Princeton University) report the discovery of a dodecagonal quasicrystal Mn72.3Si15.6Cr9.7Al1.8Ni0.6—composed of a periodic stacking of atomic planes with quasiperiodic translational order and 12-fold symmetry along the two directions perpendicular to the planes. They found it in a fulgurite consisting predominantly of fused and melted sand along with traces of melted conductor metal from a nearby downed power line. According to the researcher fulgurite may have been created by a lightning strike that combined sand with material from downed power line or from electrical discharges from the downed power line alone. It reached temperatures of at least 1,710 °C as indicated by the […]
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 […]
Scientists unveil least costly carbon capture system to date
Science Daily January 23, 2023 Rigorous process modeling and techno-economic analyses are limited for emerging carbon capture technologies. A team of researchers in the US (PNNL, industry, Washington State University) has developed four CO2-Binding Organic Liquids (CO2BOLs), all water-lean solvents, as promising options towards energy-effective and low-cost carbon capture from point sources. CO2BOLs can capture up to 97–99% CO2 from coal fired plant. The estimated carbon capture cost is about 12–23% less expensive than the conventional aqueous amine technology. In addition to vapor liquid equilibrium and kinetics (key properties for aqueous solvents), viscosity, volatility, and hydrophobicity, also have strong impacts […]