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 […]
Category Archives: Advanced materials
New metamaterial morphs into new shapes, taking on new properties
Science Daily September 11, 2019 Most reconfigurable materials can toggle between two distinct states and require a persistent external stimulus to change from one shape to another and stay that way. Using two-photon lithography a team of researchers in the US (Caltech, GeorgiaTech) designed a silicon-coated lattice with microscale straight beams that bend into curves under electrochemical stimulation, taking on unique mechanical and vibrational properties. They built in defects in the architected material system, based on a pre-arranged design. The material has potential for energy storage systems, provides a novel pathway for development of next generation smart batteries with both […]
Graphene-based fabric protects against mosquitoes
Physics World August 28, 2019 Researchers at Brown University investigated the fundamental interactions between graphene-based films and the globally important mosquito species, Aedes aegypti, through a combination of live mosquito experiments, needle penetration force measurements, and mathematical modeling of mechanical puncture phenomena. The results showed that graphene or graphene oxide nanosheet films in the dry state are highly effective at suppressing mosquito biting behavior on live human skin. Behavioral assays indicated that the primary mechanism is not mechanical puncture resistance, but rather interference with host chemosensing. This interference is proposed to be a molecular barrier effect that prevents Aedes from […]
Bacteria-killing gel heals itself while healing you
Phys.org July 25, 2019 Researchers in Canada report hierarchically structured hydrogels of self-organized M13 bacteriophage bundles, composed of hundreds of M13 nanofilaments, which exhibit both long-range and micron-scale order, are visible in electron micrographs of the cross-linked state. They adsorb up to 16× their weight in water, exhibit advanced properties at room temperature, namely, self-healing under biological conditions, autofluorescence in three channels, which decays through biodegradation, potentiating non-destructive imaging capability, and bioactivity toward the host bacteria. The latter is a powerful property, allowing the development of hydrogels with tunable bioactivity when combined with the phage display and/or recombinant DNA technology. […]
A hybrid material that switches reversibly between two stable solid states
Phys.org August 7, 2019 To obtain dual stable states, the underlying mechanism must form an energy barrier between the two, where each state rested at an energetic minimum. An international team of researchers (Canada, USA – Case Western Reserve University, Louis Stokes Cleveland DVA Medical Center, University of Pittsburgh, Carnegie Mellon University) prepared sal-gel by mixing melted sodium acetate trihydrate with polymer pre-cursors of poly(acrylic acid) and a liquid mixture of acetic acid with water. The resulting gel mixture remained transparent, suggesting the constituents to be miscible with each other. The resulting gel had two solid states; a transparent soft […]
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 […]
Physicists make graphene discovery that could help develop superconductors
EurekAlert August 1, 2019 An international team of researchers (USA – Rutgers University, Japan) studied twisted bilayer graphene, created by superimposing two layers of graphene and slightly misaligning them. This creates a “twist angle” that results in a moiré pattern which changes rapidly when the twist angle changes and have a dramatic effect on the electronic properties of the material. This is because the moiré pattern slows down the electrons that conduct electricity in graphene and zip past each other at great speeds. At a twist angle of about 1.1 degrees – the so-called magic angle – the electrons come […]
Experimental observation of a new class of materials: Excitonic insulators
Science Daily July 31, 2019 In a new study researchers in Australia have found evidence of a new phase of matter predicted in the 1960s: the excitonic insulator. It is a new phase of matter in the critical transition point between insulator and metal. The researchers studied antimony nanoflake using scanning tunneling microscopy and spectroscopy. They observed the unique feature of the excitonic insulator, a charge density wave (CDW) without periodic lattice distortion and a gap induced by the CDW near the Fermi surface, suggesting that the antimony (Sb(110)) nanoflake is an excitonic insulator. They are predicted to host many […]
Single-electrode material streamlines functions into a tiny chip
Phys.org July 29, 2019 An international team of researchers (Saudi Arabia, USA – Georgia Institute of Technology) has demonstrated transistor‐level integration of electrochemical microsupercapacitors and thin film transistor rectifiers using ruthenium oxide as the common electrode material connecting all devices in the microcircuits. Thin film rectifiers are shown to be capable of rectifying AC signal input from either triboelectric nanogenerators or standard function generators. They exhibit exceptionally slow self‐discharge rate and sufficient power to drive various electronic devices. The study opens a new avenue for developing compact on‐chip electrochemical micropower units integrated with thin film electronics, simplifying device fabrication and […]
New low-cost thermoelectric material works at room temperature
Science Daily July 22, 1019 The widespread adoption of thermoelectric devices that can directly convert electricity into thermal energy for cooling and heating has been hindered by the lack of materials that are both inexpensive and highly efficient at room temperature. A team of researchers in the US (University of Houston, MIT) has created an n-type material comprised of magnesium and bismuth. To produce a thermoelectric module using the new material, they combined it with a p-type version of the traditional bismuth-tellurium alloy. This allowed them to use just half as much tellurium as most current modules. The n-type Mg3Bi2-based […]