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Nanomaterials are chemical compounds or substances which are moderately produced and used. Nanomaterials are engineered to reveal novel properties of nanocells that contrast with related non-visible substances, such as expanded consistency, conductivity or synthetic reaction. Topological indexes are quantities related to molecules that capture the harmony of molecular structures and give scientifically related properties, such as: viscosity, boiling point, radius of gravity, and so on. Their demands in genetics, chemistry, physics and nanoscience are infinite. The molecular topology of such compounds would be clarify by the quantitative structure properties relationship (QSPR) and quantitative structure activity relationship (QSAR). Two carbon nanosheet structures such as V C 5 C 7 and H C 5 C 7 have been discussed in this article. We also computed ev-degree and ve-degree based topological indices of these structures. [ABSTRACT FROM AUTHOR]

Nanotechnology refers to technology that studies the performance and usage of materials with a structure size of 0.1 to 100 nanometers. Due to the special size of this material, it determines that this material has many more special properties than ordinary materials, such as size effect, surface effect, etc., so its application market can be said to be very broad. At present, the application of nanomaterials in daily production and life has aroused widespread concern, especially the two major blocks of biology and medicine. How to combine different properties such as magnetism and catalytic properties to form multifunctional nanomaterials and how to use the material more efficiently in the field of biology has become a research direction of experts. Machine learning can realize the automatic identification of non-good wood, which effectively avoids the impact of visual fatigue or other subjective factors in the manual identification process, and machine learning has a more accurate positioning of the standard of non-good wood, thereby improving the wood's quality. Usage rate. In this paper, the fuzzy analytic hierarchy process is mainly used to study the catalytic performance of nanocomposites on glucose oxidation. Compared with glassy carbon bare electrode (GCE) and IL-GR / GCE, N i 3 S 2 / IL-GR / GCE showed significant electrocatalytic activity for glucose oxidation. The linear range is 0 ∼ 1000 μM, and the detection limit is 0.162 μM (S / N = 4). The results showed that the current response of glucose did not change significantly, proving that N i 3 S 2 / IL-GR / GCE has a strong anti-interference ability. [ABSTRACT FROM AUTHOR]

Copper oxide (CuO) nanofibers were successfully prepared by electrospinning and subsequent heat treatment. The chemical composition and morphology of the fibers were characterized by SEM, XRD and EDS. Beaded nanofibers with 100nm in diameter were prepared by simple electrospinning and calcining. The catalytic effect of CuO nanofibers on the combustion of ammonium perchlorate (AP) was investigated by TG and DTA. The results showed that the decomposition temperature of AP shifted by 101.9 °C to the low temperature and the catalytic efficiency was very high. This is mainly attributed to the higher surface to volume ratio of beaded copper oxide nanofibers compared with smooth nanofibers and spherical nanoparticles. The results suggest that the electrospinning of CuO nanofibers is a promising one-dimensional nanometer material in the field of propellant catalysis. [ABSTRACT FROM AUTHOR]

This work shows, for the first time, that the multi-walled carbon nanotubes (MWCNTs) exhibit the catalytic activity in the ethylene hydrogenation. MWCNTs with the average diameter of 35 nm were prepared by CVD from ethylene as a carbon source at 700 °C. TEM, SEM, and XRD indicate that MWCNTs are characterized by a sufficiently high defectiveness. FTIR highlights that the catalytic process occurs in the presence of the hydroxyl and carbonyl surface groups. We demonstrate the high catalytic stability of MWCNTs at temperatures up to 400 °C. [ABSTRACT FROM AUTHOR]

This article concerns the investigation of the vibrational behavior of double-walled carbon nanotubes/double-layered graphene sheets junctions using the finite element method. The bonds and atoms are modeled by beam and mass elements, respectively. Moreover, the van der Waals interactions are simulated by spring elements. The effects of the length of the nanotube and the dimensions of the nanosheet on the natural frequencies of the junctions are examined. It is shown that when the boundary conditions are applied on the nanotube, the geometrical parameters of nanotubes have a significant effect on the vibrational behavior of the junctions. [ABSTRACT FROM PUBLISHER]

Carbon nanofibers (CNFs) were prepared by chemical vapor deposition with Cu2O nanoparticles as a catalyst and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared absorption spectrum (IR). Effects of hydrogen reduction, acid treatment and growth temperature on component and structures of CNFs were studied. According to the IR analysis, both ‒C‒C‒ conjugated bonds and ‒CH3, ‒CH2‒ saturated groups existed in carbon nanofibers. The degree of their oxidation was determined by the growth conditions. While the activity of the catalyst varied with temperature. The growth mechanism of CNFs was also discussed in this work. [ABSTRACT FROM AUTHOR]

High density polyethylene (HDPE)/poly (ethylene terephthalate) (PET) (90/10 wt.%) blends and HDPE/PET/multi-walled carbon nanotubes (MWCNTs) nanocomposites were prepared by melt mixing process, and the influence of MWCNTs on the mechanical and rheological properties of the nanocomposites was investigated. MWCNTs were added up to 5 wt.% in the HDPE/PET matrix. Transmission electron microscopy images reveal that the MWCNTs were homogeneously dispersed in the HDPE/PET matrix. Improvement of mechanical properties was observed by the addition of MWCNTs compared with HDPE/PET blends. Prominent increases in the complex viscosity and storage modulus of the nanocomposites were found with increasing MWCNT content. [ABSTRACT FROM PUBLISHER]

Carbon nanofibers were in-situ grown on graphite-felt, and then Ru was supported to synthesize Ru/CNFs/GF structured catalyst. The comparisons of pressure gradient and reaction results clearly indicated that the Ru/CNFs/GF structured catalyst was more proper than powdered Ru/CNFs catalyst for sorbitol hydrogenolysis in a trickle bed reactor. For the structured catalyst, increasing the linear velocities would increase the sorbitol conversion, but only slightly change the glycols selectivity, which was due to the intensified mass transfer. Nevertheless, increasing the thickness of the carbon nanofibers layer would significantly decrease the glycols selectivity, which was due to the increased diffusion distance for hydrogen and glycols in the mesopores of the carbon nanofibers layer. [ABSTRACT FROM PUBLISHER]

Several conductive nanomaterials are investigated for structural electrically conductive adhesive applications, including carbon nanofibers and nickel nanostrands. The suitability of nanostrands as a conductive filler is reviewed. Adhesive formulations based on Hysol 9396 epoxy are tested for electrical and structural properties. Several formulations are found to be capable of providing enhanced adhesive strength while affording excellent electrical conductivity. The development of full strength structural conductive adhesives can enable a wide range of applications where the strength of current commercially available electrically conductive adhesive systems is a limiting factor. Superior conductivity results are obtained by the nickel nanomaterials, with milliohm gap resistance and resistivity on the order of 10-2 Ω cm possible at loading of 5 vol%. Initial results indicate that these systems present good survivability in thermal cycling conditions. [ABSTRACT FROM AUTHOR]

The removal of methylene blue (MB), a cationic dye and orange II (OII), an anionic dye, from aqueous solution by using carbon nanomaterials as multiwalled carbon nanotubes (MWNTs) and carbon nanofibers (CNF) as adsorbents was studied in batch experiments. The effect of pH, temperature and surface modification of adsorbent on the removal of MB and OII was also investigated. The removals of OII and MB by adsorption on MWNT were maximum at pH 3.0 and pH 7.0, respectively. However, in the case CNF was employed as adsorbent, the optimum values of pH were 9.0 and 5.0 for OII and MB, respectively. Langmuir and Freundlich isotherms are applied to fit the adsorption data of both dyes. Equilibrium data were well described by the typical Langmuir adsorption isotherm. Overall, the study demonstrated that MWNTs and CNFs can effectively remove cationic and anionic dyes as MB and OII from aqueous solutions under these experimental conditions. [ABSTRACT FROM AUTHOR]

We have successfully fabricated straight carbon nanofibers containing coiled carbon nanofibers by ethanol catalytic combustion technique. In our experiment, copper plate was employed as substrate, transition metal salt solution as catalyst precursor, and ethanol as carbon source. The morphology and microstructure of the obtained carbon nanostructures have been investigated and their growth mechanism has been discussed. [ABSTRACT FROM AUTHOR]

Systematic investigations were carried out into the sorption of rare earth elements (REEs) on carbon nonofibers (CNFs) by inductively coupled plasma mass spectrometry (ICP-MS). The experimental parameters for preconcentration of REEs, such as pH, sample flow rate and volume, eluent concentration, and interfering ions on preconcentration of REEs have been examined in detail. The studied metal ions can be adsorbed quantitatively on CNFs in a pH range from 2.0 to 5.0, and then eluted completely with 0.5 mol l-1 HNO3. Based on the above facts, a novel method using a microcolumn packed with carbon nanofibers as an adsorption material was developed for the separation and preconcentration of REEs prior to their determination by ICP-MS. The proposed method has been successfully applied to the determination of light (La), medium (Eu and Gd) and heavy (Yb) rare earth elements in real sample with the recovery more than 90%. In order to validate this method, two certified reference materials of tea leaves (GBW 07605) and mussel (GBW 08571) were analyzed, and the determined values are in good agreement with the certified values. [ABSTRACT FROM AUTHOR]

The shear-induced crystallization behavior of isotactic polypropylene (iPP) nanocomposite melt containing modified carbon nanofibers (MCNFs) was investigated by rheo-SAXS (small-angle X-ray scattering) and rheo-WAXD (wide-angle X-ray diffraction) techniques using synchrotron radiation. Under quiescent conditions, the nucleating effect of MCNFs on crystallization of iPP was pronounced and the system exhibited a remarkably low saturation point (ca. 0.05 wt% of MCNF). In-situ SAXS and WAXD results showed the development of shear-induced crystalline structures and lamellar morphology in nanocomposite melts. Under the same shear conditions, the filled system exhibited notably faster kinetics compared with the unfilled system. The oriented crystalline fraction was found to decrease with the MCNF loading, indicating the competition between oriented crystals (induced by shear) and unoriented crystals (due to the nucleating effect of MCNF). At the early stages of crystallization, the amount of the oriented crystals increased with the MCNF concentration, suggesting that the nanofiller hindered the motion of polymer chains after the cessation of flow resulting in the delayed relaxation of stretched polymer segments. [ABSTRACT FROM AUTHOR]