Nanowerk December 4, 2019 Researchers at Northwestern University designed the picoscale crystalline structure of molybdenum oxynitride (MoON), to host the phase transition. The researchers found the metal-insulator transition (MIT) occurred near 600 degrees Celsius, revealing its potential for applications in high-temperature sensors and power electronics. They noted multiple design parameters influenced MoON’s phase transition. The inclusion of multiple anions in the material activated the phase transition due to specific electron configurations related to the spatial orientation of electronic orbitals. The findings offer insight into how subtle changes on the nanoscale can be used to control macroscopic behavior, like conductivity, in […]
Category Archives: Advanced materials
Metal-organic framework captures and converts toxic air pollutant into industrial chemical
Nanowerk November 23, 2019 An international team of researchers (UK, USA – Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory) has developed an MOF, denoted as MFM-520, that can capture atmospheric nitrogen dioxide at ambient pressures and temperatures—even at low concentrations and during flow—in the presence of moisture, sulfur dioxide and carbon dioxide. Despite the highly reactive nature of the pollutant, MFM-520 proved capable of being fully regenerated multiple times by degassing or by treatment with water from the air—a process that also converts nitrogen dioxide into nitric acid. The highest rate of NO2 uptake by this material occurs at […]
Synthetic biologists developing a new class of high-performance materials
Science Daily November 18, 2019 A team of researchers in the US (Northwestern University, University of Illinois, Stanford University, UT Austin, industry) developed a set of design rules to guide how ribosomes, a cell structure that makes protein, can incorporate new kinds of monomers, which can be bonded with identical molecules to form polymers. The rules guide how ribosomes, a cell structure that makes protein, can incorporate new kinds of monomers, which can be bonded with identical molecules to form polymers. These findings are an exciting step forward to achieving sequence-defined synthetic polymers. The ability to harness and adapt cellular […]
Invention of teeny-tiny organic films could enable new electronics
Phys.org November 8, 2019 A team of researchers in the US (University of Chicago, Cornell University, Argonne National Laboratory) filled a reactor halfway with liquid A, then add liquid B. At the line where the two meet, they used a tiny tube to inject the rest of the ingredients, which assembled into a film. Then scientists evaporated or drain the liquids, and the film gently glides down to rest intact. The film grows in one continuous motion, so there are no awkward joints between patches. It can be performed at room temperature. The method provides an innovative way to combine […]
Researchers develop thin heat shield for superfast aircraft
Phys.org November 13, 2019 Existing heat shields are often very thick compared to the base they protect. Researchers at Florida State University designed a carbon nanotube/phenolic thermal protection layer (TPL) with heat shield functionality while maintaining designed mechanical strength compared to traditional carbon fiber reinforced polymers (CFRP) composites. These TPLs were integrated onto the surface of carbon fiber/bismaleimide composites to act as a heat shield for hybrid composites. The TPLs resulted in a 17% decrease of the through-thickness thermal conductivity for hybrid composites. The material retained its flexibility and strength after flame torch test It has the potential to protect […]
Stretchable, degradable semiconductors
Science Daily November 13, 2019 Researchers at Stanford University decoupled the design of stretchability and transience by harmonizing polymer physics principles and molecular design to develop a material that simultaneously possesses three disparate attributes: semiconductivity, intrinsic stretchability, and full degradability. They have shown that the semiconducting nanofibers concurrently enable controlled transience and strain-independent transistor mobilities. They anticipate that these materials could be used to build fully biodegradable diagnostic or therapeutic devices, environmental monitors, and advance developing multifunctional materials for skin-inspired electronic devices…read more. Open Access TECHNICAL ATRICLE IMAGE https://pubs.acs.org/na101/home/literatum/publisher/achs/journals/content/acscii/0/acscii.ahead-of-print/acscentsci.9b00850/20191031/images/medium/oc9b00850_0005.gif CAPTION Abstract. Credit: ACS Central Science, November 13, 2019 https://pubs.acs.org/doi/10.1021/acscentsci.9b00850
An electronic signal expands the material by a factor of 100
EurekAlert October 29, 2019 Materials, such as solids and gels, that change volume depending on temperature or pH have long been available. An international team of researchers (Sweden, UK) placed a conducting polymer with a thickness of a few micrometres around an electrically conducting carbon fibre. When electrical pulses with magnitudes of +0.5 V or +0.8 V are applied, the material changes its internal structure, then absorbs water and is finally converted to a gel that expands to 14 or 120 times the original volume. When pulses of magnitude +/- 0.5 V are repeatedly applied, the material expands by approximately […]
Creating 2D heterostructures for future electronics
Science Daily October 11, 2019 Integration of dissimilar 2D materials is essential for nanoelectronic applications. Compared to vertical stacking, covalent lateral stitching requires bottom-up synthesis, resulting in rare realizations of 2D lateral heterostructures. Because of its polymorphism and diverse bonding geometries, borophene is a promising candidate for 2D heterostructures, although suitable synthesis conditions have not yet been demonstrated. Researchers at Northwestern University report lateral and vertical integration of borophene with graphene. Topographic and spatially resolved spectroscopic measurements reveal nearly atomically sharp lateral interfaces despite imperfect crystallographic lattice and symmetry matching. Boron intercalation under graphene results in rotationally commensurate vertical heterostructures. […]
Unique sticky particles formed by harnessing chaos
Phys.org October 14, 2019 The soft dendritic particle materials with unique adhesive and structure-building properties can be created from a variety of polymers precipitated from solutions under special conditions. An international team of researchers (USA – North Carolina State University, the Netherlands, UK) used ‘liquid’ nanomanufacturing to convert most polymers into branched particles after dissolving the polymer and mixing the solution rapidly with another liquid. Rapid mixing in turbulent flow creates branched particles organized in a hierarchical way. The thinnest branches surrounding these particles form a corona of nanofibers that distributes their stickiness by van der Waals forces. The process […]
Accidental discovery of strong and unbreakable molecular switch
Science Daily October 8, 2019 An international team of researchers (the Netherlands, China) report that fluorenone derivative (4-DBpFO) shows a strong shear deformation upon heating due to a structural phase transition which is reproducible after more than hundred heating/cooling cycles. Molecular dynamic simulations show that the transition occurs through a nucleation-and-growth mechanism, triggered by thermally induced rotations of the phenyl rings, leading to a rearrangement of the molecular configuration. This material can serve as a prototype structure to direct the development of new types of robust molecular actuators…read more. Open Access TECHNICAL ARTICLE