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 […]
Tag Archives: Materials science
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
Finding the ‘magic angle’ to create a new superconductor
Science Daily October 2, 2019 Earlier this year, scientists at MIT reported that graphene could become a superconductor if one piece of graphene were laid on top of another piece and the layers twisted to a specific angle , they called “the magic angle” of between 1 degree and 1.2 degrees. Now an international team of researchers (USA – Ohio State University, TT Dallas, Japan) found that graphene layers still superconducted at a smaller angle, around 0.9 degrees. It is a small distinction, but the findings provide a wealth of new information to help decipher the strongly correlated phenomena observed […]
New silk materials can wrinkle into detailed patterns, then unwrinkle to be ‘reprinted’
Science Daily October 7, 2019 Water and methanol vapor, for example, can soak into the fibers and interfere with hydrogen bond cross links in the silk fibroin, causing it to partially ‘unravel’ and release tension in the fiber. Taking advantage of this property, the researchers at Tufts University fabricated a silk surface from dissolved fibroin by depositing it onto a thin plastic membrane (PDMS). After a cycle of heating and cooling the silk surface of the silk/PDMS bilayer folds into nanotextured wrinkles due to the different mechanical properties of the layers. Exposing any part of that wrinkled surface to water […]
MIT engineers develop “blackest black” material to date
MIT News September 12, 2019 The material reported by researchers at MIT is made from vertically aligned carbon nanotubes that the team grew on a surface of chlorine-etched aluminum foil. The foil captures at least 99.995 percent of any incoming light, making it the blackest material on record. They suspect that it may have something to do with the combination of etched aluminum, which is somewhat blackened, with the carbon nanotubes. In an exhibit called Redemption of Vanity they demonstrated the material by making a brilliantly faceted 16.78 carat diamond appear as a flat, black void by coating it with […]
Researchers use laser light to transform metal into magnet
Phys.org September 16, 2019 Up to now, researchers have only been capable of manipulating the properties already found in a material using light. An international team of researchers (Denmark, Singapore) has shown that when the material is irradiated with laser light, plasmons in the metal disk begin to rotate in either a clockwise or counterclockwise direction. However, these plasmons change the quantum electronic structure of a material, which simultaneously alters their own behavior, catalyzing a feedback loop. Feedback from the plasmons’ internal electric fields eventually causes the plasmons to break the intrinsic symmetry of the material and trigger an instability […]
Measuring changes in magnetic order to find ways to transcend conventional electronics
Science Daily September 6, 2019 Recent studies have shown that the antiferromagnetic AFM order parameter can be ‘switched’ (that is, change it from one known value to another, fast) using light or electric currents. However, the dynamics of the order-switching process are not understood. Current approaches rely on measuring only certain phenomena during AFM order switching and they are not reliable. An international team of researchers (Switzerland, Japan) used second-harmonic generation whose output value is directly related to the AFM order parameter and combined it with measurements of the Faraday effect. Combining these two different measurement methods, the researchers managed […]
Molecule properties change through light
Phys.org September 9, 2019 Researchers in Germany have developed and manufactured a novel molecule called 3-methoxy-9-fluorenylidene which is based on a fluorine scaffold with a methoxy group attached in the shape of a rotational tail. They figured out that the molecule’s magnetic properties are determined by the orientation of the methoxy group, which changes its conformation depending on the kind of light that hits it. It can be used to switched on and off magnetism; it is not brittle like conventional magnets, but flexible and can be processed like plastics. Using this group of atoms, we can study the spin […]
Switching electron properties on and off individually
Science Daily August 22, 2019 An international team of researchers (Austria, USA – Rice University, University of Florida, Germany) investigated a material made of palladium, silicon and cerium focusing on the electrons located at the cerium atom and on the conduction electrons, which can move freely through the crystal. The conduction electrons can virtually hide both the spin and the orbital state of the fixed electrons. This means that order is no longer possible. They have developed a system in which the order can be switched on and off individually in relation to two different degrees of freedom that are […]
New process discovered to completely degrade flame retardant in the environment
EurekAlert August 8, 2019 Among the most common flame retardants that hinder combustion and slow the spread of fire, tetrabromobisphenol A (TBBPA) is added to manufactured materials, including computer circuit boards and other electrical devices, papers, textiles and plastics. With a variety of health concerns, including cancer and hormone disruption, TBBPA has been widely detected in the environment, as well as in animals and human milk and plasma. It is a persistent global pollutant nontoxic. An international team of researchers (USA – UMass Amherst, China) has developed a process that breaks down TBBPA to harmless carbon dioxide and water. The […]