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Multiple twinning to form fivefold twinned nanoparticles in crystal growth is common and has attracted broad attention ranging from crystallography research to physical chemistry and materials science. Lattice-misfit strain and defects in multiple twinned nanoparticles (MTP) are key to understand and tailor their electronic properties. However, the structural defects and related strain distributions in MTPs are poorly understood in three dimensions (3D). Here, we show the 3D atomic misfit and strain relief mechanism in fivefold twinned icosahedral nanoparticles with amorphization and dislocations by using atomic resolution electron tomography. We discover a two-sided heterogeneity in variety of structural characteristics. A nearly ideal crystallographic fivefold face is always found opposite to a less ordered face, forming Janus-like icosahedral nanoparticles with two distinct hemispheres. The disordered amorphous domains release a large amount of strain. Molecular dynamics simulations further reveal the Janus-like icosahedral nanoparticles are prevalent in the MTPs formed in liquid-solid phase transition. This work provides insights on the atomistic models for the modelling of formation mechanisms of fivefold twinned structures and computational simulations of lattice distortions and defects. We anticipate it will inspire future studies on fundamental problems such as twin boundary migration and kinetics of structures in 3D at atomic level. The crystallographically forbidden fivefold symmetry in icosahedra remains a long-standing mystery. Here, the authors resolve the three-dimensional atomic structure of Janus-like icosahedral nanoparticles with atomic resolution by electron tomography. [ABSTRACT FROM AUTHOR]

Preventing the penetration of water while allowing it to pass through quickly is the key to achieving waterproof and breathable membranes; it opens up new possibilities for applications in all areas. Herein a novel functional nanofibrous membrane can be prepared via a facile electrospinning strategy, thermal post-treatment and chemical cross-linking, capable of providing excellent mechanical performance. Low-melting-point polyvinyl butyral (PVB) elastomer are added to polyvinylidene fluoride (PVDF) to modify the bonding network structure of the interfiber-adherent membrane, imparting durability and high mechanical properties to the membrane. Subsequently, the blocked isocyanate prepolymer (BIP) is used as the chemical cross-linker with PVDF and polyvinyl butyral (PVB) hybrid system to strengthen the cross-linking structure. Through systematically characterize the morphologies, contact angle, water vapor transmittance rate (WVTR) and hydrostatic pressure, it is studied that the effect of concentrate of PVDF/PVB/BIP and thermal-induced temperature on the waterproofness and breathability. The results indicate that the prepared nanofibrous membranes can maintain highly hydrostatic pressure (93.27kPa) and high WVTR (10.28 kg m−2 d−1); meanwhile, the membranes exhibit the excellent tensile stress (13.07MPa), indicating that it has a broad potential application prospect in the separation process and protective clothing. [ABSTRACT FROM AUTHOR]

Human activities in cold climates are more and more frequent. But, an efficient strategy to maintain the human body temperature is still a challenging work. In this paper, we propose a photothermal polyurethane/zirconium carbide(PU/ZrC) fibrous membrane assembled via electrospinning technique, which can make up for heat lost from the human body by absorbing and converting light energy. When the content of ZrC nanoparticles (Nps) was increased to 8%, the surface temperature of the composite fibrous membrane was increased to 66.5 °C after illumination for 150 s under a Xenon lamp. Besides, the surface morphologies, crystallization behavior, thermal property, mechanical property, wettability and air permeability of the fibrous membranes were also evaluated. The morphology of the fibrous membranes exhibited that mesh-like fibers were densely aligned and the hydrophobicity of the PU/ZrC composites could be improved when ZrC Nps were added. Moreover, the PU/ZrC membrane with low content of ZrC has outstanding mechanical properties and good air permeability. Our results indicate that the PU/ZrC membranes may have promising potentials in the applications of personal thermal management textiles. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) atomic arrangements in the surface and subsurface parts of nanomaterials are crucial for understanding their structure-functionality correlations. However, unveiling the required structure at such a resolution remains a challenge due to the lack of effective imaging and reconstruction techniques. Here, we determine the 3D atomic surface and subsurface structures of Au@Pd core-shell nanoparticles and study their correlations with electronic and surface chemical properties using atomic-resolution electron tomography (AET). We find that the intermixing of Au and Pd is the key factor that influences the surface and subsurface structure and quantitatively reveals its negative correlations with bond disorder and tensile strain. By applying spectroscopic and electrochemical measurements, we confirm that different surface structures modify the electronic and chemical properties at different Au/Pd ratios. These results not only shed light on the complex surface and subsurface structures of realistic nanomaterials but also deepen our understanding of structure-functionality correlations in nanostructures at the single-atom level.