Papers by Keyword: Structural Characterisation

Abstract: This paper mainly introduces the origins, basic structures and family members of carbon, the focus is a new generation of nanomaterial－graphene. In the experiment, a series of tests are taking place firstly, such as SEM, TEM, XRD, XPS, BET, Infrared spectrum, Raman spectrum and Laser particle size analysis. The results show that the graphene has excellent mechanical properties, optical performance, electrical properties and conductive properties. Especially super conducting properties of graphene. Then the basic principle of electromagnetic shielding effectiveness, test methods and condition analysis are analyzed in this paper.

Abstract: The synthesis and characterisation of various organic-inorganic nanohybrids are reported in this contribution. The host material was Ca₃Fe-LDH prepared by the co-precipitation method. E-cinnamate, E-4-nitrocinnamate or E-2,5-difluorocinnamate anions were the guests. Successful intercalation occurred through the introduction of the guest anion into the interlayer region of the host materials with the dehydration-rehydration method. The obtained nanohybrids were studied by powder X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence (EDX) coupled to the SEM instrument and infrared spectroscopy (IR). These methods were used on one hand to prove that intercalation was successful and for the characterisation of the substances on the other. Molecular modelling was used for visualising the possible spatial arrangement of the organic anions.

Abstract: A chain Ni (II) coordination polymer material was prepared and characterized by elemental analysis and single-crystal X-ray diffraction. It crystallizes in monoclinic, space group C2/c with a = 1.24348(13) nm, b = 1.29477(12) nm, c = 1.51480(17) nm and Dc = 1.401 g•cm-3. The results of structural analysis indicated that each Ni (II) ion forms six-coordinated with nitrogen atoms of pyridine and thiocyanate, and the Ni (II) coordination polymer material formed one dimensional chain structure by the interaction of pyridine rings.

Abstract: A novel ring-like zinc (II) complex of N-paratoluensulfonyl-glycine acid and 1,10-phenanthroline was synthesized and characterized by elemental analysis, IR spectrum and molar conductivity. The crystal structure of Zn (II) was determined by X-ray single crystal diffraction. The results show that each zinc (II) atoms is in a distorted trigonal bipyramidal geometry and form 16-membered chelate ring with the tridentate ligand. Intermolecular weak interactions in complex link molecules into a one-dimensional infinite chain supramolecular structure. The luminescence property of the complex was investigated in solid.

Abstract: Large-scale highly aligned boron carbon nitride (BCN) needle-like nanostructures were synthesized directly on Si (100) substrates by the novel technique of magnetron sputtering of the boron and graphite targets in a N₂+Ar gas mixture at the substrate temperature of 800 °C. XRD reveals that the nanostructures contain an inhomogeneous crystalline structure. The hybridized BCN phases with needle-like nanostructures should now be regarded as semiconductors may be used as electron emitters for field electron emission applications.

Abstract: A novel biomass composite, wood-polymer composite with potential good mechanical properties, durability and environmental characteristic capable of applying in fields of construction and traffic as structural material, was prepared by generating high-performance polymer from in situ polymerization of styrene in wood porous structure. The vinyl monomer, styrene, combing with 1wt% AIBN as an initiation, was first impregnated into wood porous structure under a vacuum/pressure condition, and then in situ polymerized through a thermal treatment. The structure of the resultant composite was characterized by SEM, FTIR and XRD. Results show that styrene polymerized into polystyrene through free radical polymerization, and the resultant polymer fully filled in wood porous structure in a column form, partly contacting wood matrix. FTIR analysis indicates that polystyrene generated into wood pores, indicating weak interaction between them. XRD analysis suggests that the polystyrene generated into wood pores mainly existed in an amorphous form.

Abstract: Bi-Pb-Sr-Ca-Cu-O (BPSCCO) and Bi-Pb-Sb-Sr-Ca-Cu-O (BPSSCCO) thin films were grown on MgO single crystal substrates by pulsed laser deposition. The deposition was carried out at room temperature during 90 minutes. A Nd:YAG excimer laser ( = 355 nm) with a 2 J/pulse energy density operated at 30 Hz was used. The distance between the target and substrate was kept constant at 4,5 cm. Nominal composition of the targets was Bi1,6Pb0,4Sr2Ca2Cu3O and Bi1,6Pb0,4Sb0,1Sr2Ca2Cu3OSuperconducting targets were prepared following a state solid reaction. As-grown films were annealed at different conditions. As-grown and annealed films were characterized by XRD, FTIR, and SEM. The films were prepared applying an experimental design. The relationship among deposition parameters and their effect on the formation of superconducting Bi-system crystalline phases was studied.

Abstract: This work looked for to search out systematically, in scale of laboratory, copper-nickel-aluminum alloys (Cu-Ni-Al) with conventional powder metallurgy processing, in view of the maintenance of the electric and mechanical properties with the intention of getting electric connectors of high performance or high mechanical damping. After cold uniaxial pressing (1000 kPa), sintering (780oC) and suitable homogenization treatments (500oC for different times) under vacuum (powder metallurgy), the obtained Cu-Ni-Al alloys were characterized by optical microscopy, electrical conductivity, Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, hardness, macrostructures and microstructures of the samples.

Abstract: The aim of this work, using the powder metallurgy process, is to synthesize metallic alloys with high mechanical strength and high electric conductivity, after melting optimizing and thermal treatments. The Cu-Ni-Cr (wt%) alloys are characterized in their mechanical and electrical properties as well as the obtained microstructure. Through the process of powder metallurgy, contacts and structural parts can be obtained. The alloys elements are added to copper with the intention to improve their strength, ductility and thermal stability, without causing considerable damages in their form, electrical and thermal conductivity, and corrosion resistance. The metallic powders were mixed for a suitable time and then they were pressed in a cold uniaxial pressing (1000 kPa). Afterwards, the specimens were sintered in temperatures varying from 700 up to 800oC under vacuum. At last, the samples were homogenized at 550oC under vacuum, for special times. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples. The alloys were characterized by optical microscopy, x rays powder diffraction, electrical conductivity and Vickers hardness.

Abstract: The aim of this article was to analyze the microstructural development in samples of Cu-Ni-Sn alloys (weight %) obtained by powder metallurgy (P/M). The powders were mixed for 1/2 hour. After this, they were pressed, in a cold uniaxial pressing (1000 kPa). In the next step the specimens were sintered at temperatures varying from 650 up to 780°C under vacuum. Secondly, the samples were homogenized at 500oC for several special times. The alloys were characterized by optical microscopy, electrical conductivity and Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples.