Current Issue : April - June Volume : 2020 Issue Number : 2 Articles : 5 Articles
Lightweight, high-strength and electrically conductive poly(butylene succinate) (PBS)/\ncarbon black (CB) nanocomposite foams with a density of 0.107â??0.344 g/cm3 were successfully\nfabricated by a solid-state supercritical CO2 (ScCO2) foaming process. The morphology, thermal\nand dynamic mechanical properties, and rheological behavior of the PBS/CB nanocomposites were\nstudied. The results indicate that the CB nanofiller was well dispersed in the PBS matrix and the\npresence of a proper CB nanofiller can accelerate the rate of crystallization, improve the thermal\nstability, enhance the stiffness, and increase the complex viscosity of PBS/CB nanocomposites. These\nimproved properties were found to play an important role in the foaming process. The results\nfrom foaming experiments showed that the PBS/CB nanocomposite foams had a much smaller cell\nsize, a higher cell density, and a more uniform cell morphology as compared to neat PBS foams.\nFurthermore, the PBS/CB nanocomposite foams also possessed low density (0.107â??0.344 g/cm3), good\nelectrical conductivity (Approximately 0.45 S/cm at 1.87 vol % CB loading), and improved compressive strength\n(108% increase), which enables them to be used as lightweight and high-strength functional materials....
Metallic film-coated porous silicon (PSi) has been reported as a lucrative surface-enhanced\nRaman scattering (SERS) substrate. The solution-based fabrication process is facile and easy; however,\nit requires additional reducing agent and extra chemical treatment, as well as hinders the suitability\nas a reproducible SERS substrate due to irregular hot spot generation via irregular deposition of\nmetallic nanocrystallites. To address this issue, we report a unique one-step electronic beam (e-beam)\nphysical vapor deposition (PVD) method to fabricate a consistent layer of gold (Au) nanofilm on PSi.\nMoreover, to achieve the best output as a SERS substrate, PSi prepared by electrochemical etching\nwas used as template to generate an Au layer of irregular surface, offering the surface roughness\nfeature of the PSiâ??Au thin film. Furthermore, to investigate the etching role and Au film thickness,\nAu-nanocrystallites of varying thickness (5, 7, and 10 nm) showing discrete surface morphology\nwere characterized and evaluated for SERS effect using Rhodamine 6G (R6G). The SERS signal of\nR6G adsorbed on PSiâ??Au thin film showed a marked enhancement, around three-fold enhancement\nfactor (EF), than the Siâ??Au thin film. The optimal SERS output was obtained for PSiâ??Au substrate of\n7 nm Au film thickness. This study thus indicates that the SERS enhancement relies on the Au film\nthickness and the roughness feature of the PSiâ??Au substrate....
In the enormous and still poorly mastered gap between the macro level,\nwhere well developed continuum theories of continuous media and engineering\nmethods of calculation and design operate, and atomic, subordinate\nto the laws of quantum mechanics, there is an extensive meso-hierarchical\nlevel of the structure of matter. At this level unprecedented previously products\nand technologies can be artificially created. Nano technology is a qualitatively\nnew strategy in technology: it creates objects in exactly the opposite\nwayâ??large objects are created from small ones [1]. We have developed a new\nmethod for modeling acoustic monitoring of a layered-block elastic medium\nwith several inclusions of various physical and mechanical hierarchical structures\n[2]. An iterative process is developed for solving the direct problem for\nthe case of three hierarchical inclusions of l, m, s-th ranks based on the use of\n2D integro-differential equations. The degree of hierarchy of inclusions is determined\nby the values of their ranks, which may be different, while the first\nrank is associated with the atomic structure, the following ranks are associated\nwith increasing geometric sizes, which contain inclusions of lower\nranks and sizes. Hierarchical inclusions are located in different layers one\nabove the other: the upper one is abnormally plastic, the second is abnormally\nelastic and the third is abnormally dense. The degree of filling with inclusions\nof each rank for all three hierarchical inclusions is different. Modeling is carried\nout from smaller sizes to large inclusions; as a result, it becomes possible\nto determine the necessary parameters of the formed material from acoustic\nmonitoring data....
A facile, one-pot hydrothermal method was used to synthesize Nickel selenide (NiSe)\nnanoparticles decorated with reduced graphene oxide nanosheets (rGO), denoted as NiSe/rGO.\nThe NiSe/rGO exhibits good electrochemical performance when tested as anodes for Na-ion batteries\n(SIBs) and Li-ion batteries (LIBs). An initial reversible capacity of������....
Magnetic nanoparticles and magnetic nano-species of complex topology (e.g., nanorods,\nnanowires, nanotubes, etc.) are overviewed briefly in the paper, mostly giving attention to the\nsynthetic details and particle composition (e.g., core-shell structures made of different materials).\nSome aspects related to applications of magnetic nano-species are briefly discussed. While not being\na comprehensive review, the paper offers a large collection of references, particularly useful for\nnewcomers in the research area....
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