Nanowerk December 13, 2023 Despite its prevalence, the photothermal effect in light-absorbing nanoparticles has typically been assessed using bulk measurements, neglecting near-field effects. Beyond standard imaging and therapeutic uses, nanosecond-transient photothermal effects have been harnessed for bacterial inactivation, neural stimulation, drug delivery, and chemical synthesis. While scanning probe microscopy and electron microscopy offer single-particle imaging of photothermal fields, their slow speed limits observations to milliseconds or seconds, preventing nanoscale dynamic investigations. Researchers at the University of Illinois Urbana-Champaign introduced decoupled optical force nanoscopy (Dofn), enabling nanometer-scale mapping of photothermal forces by exploiting unique phase responses to temporal modulation. They employed […]
Tag Archives: Nanomaterials
Novel approach towards nanomaterials developed
Nanowerk September 25, 2023 In a typical approach for creating nanostructures ligands are grafted onto the surfaces of nanoparticles to improve the dispersion stability and control interparticle interactions. Ligands remain secondary and usually are not expected to order significantly during superstructure formation. Researchers in Germany investigated how ligands can play a more decisive role in the formation of anisotropic inorganic–organic hybrid materials. They grafted poly(2-iso-propyl-2-oxazoline) (PiPrOx) as a crystallizable shell onto SiO2 nanoparticles. By varying the PiPrOx grafting density, both solution stability and nanoparticle aggregation behavior could be controlled. Upon prolonged heating, anisotropic nanostructures formed in conjunction with the crystallization […]
Scientists unlock reversible twisting of nanoscale materials
Nanowerk September 13, 2023 Nanomaterials usually fail to twist into helical crystals. Considering the irreversibility of the previously studied twisting forces, the reverse process (untwisting) and retwisting areas more difficult to achieve. Researchers in China have reported a new reciprocal effect between molecular geometry and crystal structure which triggered a twisting-untwisting-retwisting cycle for tri-cobalt salicylate hydroxide hexahydrate. The twisting force stemmed from competition between the condensation reaction and stacking process, different from the previously reported twisting mechanisms. The resulting distinct nanohelices gave rise to unusual structure elasticity, as reflected in the reversible change of crystal lattice parameters and the mutual […]
Nanomaterial offers new way to control fire
Nanowerk August 14, 2023 High-temperature flames can be difficult to control how it interacts with the material being processed. An international team of researchers (USA – Iowa State University, North Carolina State University, Ames National Laboratory, Canada) developed a technique that utilizes a molecule-thin protective layer to control how the flame’s heat interacts with the material allowing users to finely tune the characteristics of the processed material. They pyrolyzed alkysilanes grafted onto cellulose fibers into non-flammable SiO2 terminating surface ignition propagation, hence stalling flame propagating. Sustaining high temperatures, however, triggered gnition in the bulk of the fibers but under restricted […]
Carbon-based stimuli-responsive nanomaterials: Their classification and application
Phys.org June 5, 2023 With the development of material synthesis technology, carbon-based nanomaterials can be functionalized and used in various fields such as energy, environment, and biomedicine. Researchers in China applied carbon-based nanomaterials to different disease treatments based on their stimulus-response properties. They categorized them into carbon nanotubes, carbon nanospheres, and carbon nanofibers according to their morphology. They discussed the materials’’ applications in probes, bioimaging, tumor therapy, and other fields. They addressed the advantages and disadvantages of carbon-based stimuli-responsive nanomaterials and discussed their future perspective… read more. Open Access TECHNICAL ARTICLE
Scientists thread rows of metal atoms into nanofiber bundles
Phys.org March 6, 2023 A class of 3D atomic wires of transition metal chalcogenides (TMC) structures consisting of bundles of TMC nanofibers held together by metallic atoms in between the fibers, all forming a well-ordered lattice in its cross section are of particular interest. Depending on the choice of metal, the structure could even be made to become a superconductor. Researchers in Japan demonstrated versatile method to fabricate indium (In)-intercalated W6Te6 (In–W6Te6) bundles with a nanoscale thickness. Atomic-resolution electron microscopy revealed that In atoms were surrounded by three adjacent W6Te6 wires. First-principles calculations suggested that their wire-by-wire stacking can transform […]
Researchers find thermal limits of advanced nanomaterials
Phys.org February 15, 2023 Boron nitride nanotubes (BNNTs), structural analogues to carbon nanotubes, are a strong candidate for nanofillers in high-temperature composites due to their high thermal stability, oxidation resistance, excellent mechanical properties, and high thermal conductivity. A team of researchers in the US (FAMU-FSU College of Engineering, industry) tested samples of high-quality, high-purity BNNTs in an inert atmosphere for thermal failure up to 2500 °C. A significant fraction of the BNNTs survived temperatures as high as 2200°, and the BNNT samples were completely undamaged at temperatures as high as 1800 °C. Boron nitride (BN) nanopowders were tested identically to […]
Novel nanowire fabrication technique paves way for next generation spintronics
Nanowerk November 9, 2022 Eliminating the etching process by directly fabricating nanowires onto the silicon substrate would lead to a marked improvement in the fabrication of spintronic devices. However, when directly fabricated nanowires are subjected to annealing, they tend to transform into droplets as a result of the internal stresses in the wire. Researchers in Japan have developed a new fabrication process to make L10-ordered CoPt nanowires on silicon/silicon dioxide (Si/SiO2) substrates. They coated a Si/SiO2 substrate with a material called a ‘resist’ and subjected it to electron beam lithography and evaporation to create a stencil for the nanowires, deposited […]
Nanomaterials: Light dependent atom clusters for sensing applications
Phys.org April 1, 2022 An international team of researchers (Japan, France, Germany, Switzerland) has developed a new environment-sensing device based on the opto-ionic-electronic phenomena of an octahedral molybdenum metal (Mo6) cluster. When the Mo6 cluster is electrochemically deposited on a transparent electrode in an organic solvent containing a trace amount of water, the water permeates the deposited film. During the process, some ligand species that stabilize the frame structure of the Mo6 cluster are substituted with hydroxyl groups, and the negatively charged frame structure of the Mo6 cluster unit is stabilized by hydronium counterions. As a result, the transparent film […]
New material could mean lightweight armor, protective coatings
Science Daily July 19, 2021 An international team of researchers (USA – MIT, Caltech, Switzerland) has fabricated nanoarchitectured materials, that absorb the impact of microscopic projectiles accelerated to supersonic speeds. According to their calculations the new material absorbs impacts more efficiently than steel, Kevlar, aluminum, and other impact-resistant materials of comparable weight. Tests revealed that consistent mechanisms such as compaction cratering and microparticle capture enable this superior response. They introduced predictive tools for crater formation in these materials using dimensional analysis. These results substantially uncover the dynamic regime over which nanoarchitecture enables the design of ultralightweight, impact-resistant materials that could […]