Phys.org September 15, 2021 Researchers in Switzerland utilized a tri-functional phosphorous compound (trivinylphosphine oxide), which has the capability of reacting only with specifically added molecules (nitrogen compounds like piperazin) to form its own network inside cotton. This makes the cotton permanently fire-resistant without blocking the favorable -OH groups. This flame retardant treatment does not include carcinogenic formaldehyde. The phosphine oxide networks do not wash out. After 50 launderings, 95 percent of the flame retardant network was still present in the fabric. To fix the phosphine oxide networks inside the cellulose they treated the cotton with an aqueous solution of phosphorus […]
Category Archives: Advanced materials
Researchers create nanoparticle paste to make perovskite solar cells more efficient
Nanowerk September 10, 2021 Large-scale and low-cost approaches for creating functional nanostructures are still not developed. An international team of researchers (Russia, Italy) has developed a method to create mesoporous electron transport layer based on optically resonant silicon nanoparticles incorporated into TiO paste to be applied for perovskite (MAPbI) solar cell. The inclusion of Mie-resonant silicon nanoparticles helps to improve light absorption by a perovskite layer without reduction of the active material. The management of Si nanoantennas concentration provides a power conversion efficiency higher than 21% by increasing all main device parameters. The new silicon nanoparticles provide physical understanding on […]
GaN-on-diamond semiconductor material that can take the heat – 1000 C to be exact
Nanowerk September 9, 2021 Researchers in Japan used the surface activated bonding (SAB) method to successfully bond GaN and diamond and demonstrated that the bonding is stable even when heated to 1,000°C. A 5.3 nm-thick intermediate layer composed of amorphous carbon and diamond is formed at the as-bonded heterointerface. As the team increased annealing temperatures, the layer thickness decreased suggesting the intermediate layer can be completely removed by optimizing the annealing process. As no peeling was observed at the heterointerface after annealing at 1000°C these results indicate that the GaN/diamond heterointerface can withstand harsh fabrications processes. The material shows promise […]
Discovery of two-phase superconductivity in CeRh2As2
Science Daily August 26, 2021 Although tens of unconventional superconductors have been discovered in the past half century, there was good thermodynamic evidence of more than one superconducting phase in only one or two materials. An international team of researchers (Germany, New Zealand, UK) used thermodynamic probes to establish two-phase superconductivity in CeRh2As2. Both materials have the highest critical magnetic field to superconducting transition temperature ratio of any known superconductor. The findings can be expected to generate entirely new research directions…read more. TECHNICAL ARTICLE
Dual-phase alloy extremely resistant to fractures
Phys.org August 20, 2021 An international team of researchers (China, USA – Argonne National Laboratory, University of Tennessee, Germany) has developed a new type of multi-principal element alloys (MPEA) called DS: EHEA (Directly Solidified: Eutectic High-Entropy Alloy) that features multiscale spatial heterogeneities using eutectic high-entropy alloys. They found that a particular aluminum-iron-cobalt-nickel dual-phase alloy solidified in a herringbone micropattern that was very highly resistant to fracturing. Its secret, they discovered, was in its hard and soft phases and the way cracks formed. Those that formed during the hard phase were stopped when they reached a border with a soft phase—the […]
New insulation material provides more efficient electricity distribution
Phys.org August 26, 2021 One way to reduce transmission loses such as this is by increasing the direct current voltage level. However, an increase in the transmission voltage adversely affects the insulation of an HVDC cable. An international team of researchers (Sweden, Italy) have shown that by adding very small amounts of the conjugated poly(3-hexylthiophene) (P3HT), it is possible to lower the electrical conductivity by up to three times. The work opens new possibilities for manufacturers. The researchers believe that their discovery could lead to numerous new applications and directions for research…read more. Open Access TECHNICAL ARTICLE
Woven nanotube fibers turn heat into power
Phys.org August 16, 2021 Invisibly small carbon nanotubes aligned as fibers and sewn into fabrics become a thermoelectric generator that can turn heat from the sun or other sources into energy. An international team of researchers (USA – Rice University, Japan) made custom nanotube fibers and test their potential for large-scale applications. They fabricated a textile thermoelectric generator based on these carbon nanotube fibers, which demonstrated high thermoelectric performance, weavability, and scalability. The power factor they observed make these fibers strong candidates for the emerging field of thermoelectric active cooling, which requires a large thermoelectric power factor and a large […]
New evidence of an anomalous phase of matter brings energy-efficient technologies closer
Phys.org July 14, 2021 An international team of researchers (UK, Japan, Slovenia, India, USA – Columbia University, Switzerland) used ultrafast pump-probe microscopy to investigate the possible excitonic insulator Ta2NiSe5. Below 328 K, they observed the anomalous micrometer-scale propagation of coherent modes at velocities of ~105 m/s, which they attributed to the hybridization between phonon modes and the phase mode of the condensate. They developed a theoretical framework to support this explanation and proposed that electronic interactions provide a substantial contribution to the ordered phase in Ta2NiSe5. These results allow us to understand how the condensate’s collective modes transport energy and […]
New type of metasurface allows unprecedented laser control
Phys.org June 29, 2021 An international team of researchers (USA – Harvard University, Italy) has developed a tunable laser that has two components—a laser diode and a reflective metasurface. The metasurface surface uses supercells, groups of pillars which work together to control different aspects of light. It is designed so that only the selected wavelength has the correct direction to enter back in the diode enabling the laser to operate only at that specific wavelength. The wavelength can be changed by moving the metasurface with respect to the laser diode. The shape of the laser beam can be fully controlled […]
Unlocking radiation-free quantum technology with graphene
Nanowerk July 8, 2021 Making usable quantum technologies out of rare-earth compounds has remained a challenge because they contain critically radioactive compounds rendering them of limited use in real-world quantum technologies. An international team of researchers (Switzerland, Finland) used the sub-nanometre thickness of graphene to create heavy fermions. By layering thin sheets of carbon on top of one another in a specific pattern, where each sheet is rotated in relation to the other, it is possible to create the quantum properties effect that results in the electrons in the graphene behaving like heavy fermions. While in this work they showed the […]