Phys.org June 13, 2024 Checkerboard lattices—where the resulting structure is open, porous, and highly symmetric—are difficult to create by self-assembly. Synthetic systems that adopt such structures typically rely on shape complementarity and site-specific chemical interactions that are only available to biomolecular systems (e.g., protein, DNA). A team of researchers in the US (University of California at San Diego, Duke University) demonstrated the assembly of checkerboard lattices from colloidal nanocrystals that harnessed the effects of multiple, coupled physical forces at disparate length scales and that did not rely on chemical binding. Colloidal Ag nanocubes were bi-functionalized with mixtures of hydrophilic and […]
Tag Archives: Advanced materials
New anti-counterfeit technique packs two light-reactive images into one material
Phys.org May 30, 2024 Creating dual-mode patterns in the same area of the material increases the dimension of information storage and encryption security. However different patterns may lead to serious mutual interference in the process of manufacturing and usage. An international team of researchers (USA – Argonne National Laboratory, China) has demonstrated noninterfering dual-mode patterns by combining the structural color and chromatic polarization, which was designed with an azobenzene-containing linear liquid crystal copolymer featuring a photofluidization effect. The secondary imprinting was used to eliminate the partial damage to the structural color patterns during writing of the polarization patterns, thus obtaining […]
Study reveals potential of superparaelectric materials as gate dielectrics in next-gen microelectronics
Phys.org May 30, 2024 Previous investigations for thickness-scalable high dielectric constant (k) gate layers have failed to solve the “polarizability–scalability–insulation robustness issues. An international team of researchers (UK, China) showed that this problem could be solved by using a gate layer of a high k ferroelectric oxide in its superparaelectric (SPE) state. They showed that in the SPE, the polar order became local and was dispersed in an amorphous matrix with a crystalline size down to a few nanometers, leading to an excellent dimensional scalability and a good field-stability of the k value. As an example, a stable high k […]
Towards next-gen functional materials: direct observation of electron transfer in solids
Science Daily June 4, 2024 Nanoscale electron transfer (ET) in solids is fundamental to the design of multifunctional nanomaterials, yet its process is not fully understood. Researchers in Japan directly observed solid-state ET via a crystal-to-crystal process. They first demonstrated the creation of a robust and flexible electron acceptor/acceptor (A/A) double-wall nanotube crystal with a large window through the one-dimensional porous crystallization of heteroleptic Zn4 metallocycles with two different acceptor ligands. They constructed the electron donor incorporated-A/A nanotube crystal through the subsequent absorption of electron donor guests. They removed electrons from the electron donor guests inside the nanotube crystal through […]
Researchers create materials with unique combination of stiffness, thermal insulation
Phys.org May 29, 2024 Thermal conductivity and elastic modulus are usually positively correlated in soft materials. A team of researchers in the US (North Carolina State University, Texas A&M University) have shown anomalous correlations of thermal conductivity and elastic modulus in 2D hybrid organic–inorganic perovskites (HOIP) by engineering the molecular interactions between organic cations. By replacing conventional alkyl–alkyl and aryl–aryl type organic interactions with mixed alkyl–aryl interactions, they observed an enhancement in elastic modulus with a reduction in thermal conductivity. The anomalous dependence provided a route to engineer thermal conductivity and elastic modulus independently and a guideline to search for […]
Researchers create new type of composite material for shielding against neutron and gamma radiation
Phys.org May 24, 2024 Researchers in China created a new type of composite material for shielding against neutron and gamma radiation using micron plate Sm2O3 (samarium oxide) to reinforce boron-containing polyethylene with different specific surface areas and particle size distributions. The fillers were added to boron-containing polyethylene to create composites. The composites showed improved thermal stability, increased the melting temperature, mechanical strength, and radiation shielding properties compared to materials without the fillers. Tests revealed that the composite material could block 98.7% of neutron radiation from a 252Cf source and 72.1% of gamma radiation from a 137Cs source when the material […]
Accelerated discovery research unveils 21 novel materials for advanced organic solid-state laser technology
Phys.org May 16, 2024 To overcome the synthesis bottleneck in molecular discovery, an international team of researchers (Canada, USA – University of Illinois at Urbana-Champaign, industry, UK, Japan, Poland) developed a generalizable two-step one-pot protocol for assembling pentameric organic solid-state laser (OSL) gain materials from modular precursors, spanning over 150,000 target materials. The preparation of building blocks was distributed over the available experimental resources at four geographic locations. They found a total of 21 small-molecule emitters with improved emission gain cross sections compared with state-of-the-art OSL gain materials. The resulting data was fed into the central, machine learning–based experiment planning […]
Innovative electrospinning method creates advanced ceramic nanofibers and springs
Nanowerk May 9, 2024 Electrospinning has been applied to produce ceramic fibers using sol gel-based spinning solutions consisting of ceramic precursors, a solvent, and a polymer to control the viscosity of the solution. However, the addition of polymers to the spinning solution makes the process more complex, increases the processing time, and results in porous mechanically weak ceramic fibers. Researchers in the UK developed a coelectrospinning technique, where a nonspinnable sol consisting of only the ceramic precursor(s) and solvent(s) was encapsulated inside a polymeric shell, forming core–shell precursor fibers that were further calcined into ceramic fibers with reduced porosity, decreased […]
Scientists discover a new type of porous material that can store greenhouse gases
Phys.org April 29, 2024 Researchers in the UK have developed a two-step, hierarchical synthesis that assembled a trigonal prismatic organic cage into a more symmetric, higher-order tetrahedral cage. Both the preformed [2+3] trigonal prismatic cage building blocks and the resultant tetrahedral [4[2+3]+6]cage molecule were constructed using ether bridges. This strategy afforded the tetrahedral cage molecule excellent hydrolytic stability that was not a feature of more common dynamic cage linkers. Despite its relatively high molar mass, tetrahedral cage exhibited good solubility and crystallized into a porous superstructure. By contrast, the [2+3] building block was not porous. The tetrahedral cage molecule showed […]
Scientists develop novel liquid metal alloy system to synthesize diamond under moderate conditions
Phys.org April 24, 2024 There is an existing model that diamond can be grown using liquid metals only at both high pressure and high temperature. Researchers in South Korea described the growth of diamond crystals and polycrystalline diamond films with no seed particles using liquid metal but at 1 atm pressure and at 1,025 °C. Diamond grew in the subsurface of liquid metal composed of gallium, iron, nickel and silicon, by catalytic activation of methane and diffusion of carbon atoms into and within the subsurface regions. They found that the supersaturation of carbon in the liquid metal subsurface led to the nucleation […]