Advanced Materials Research Vols. 557-559

Abstract: At present, CNTs can be a variety of methods in the system, including arc discharge, chemical vapor deposition and laser evaporation method, which arc discharge and chemical vapor deposition method is used in two wider. No matter what kind of prepared CNTs, not high purity, containing the catalyst particles or amorphous carbon particles, graphite particles and other impurities. These impurities mixed with CNTs, it is difficult to meet the research and application needs of CNTs, and thus the study of CNTs purification is necessary. CNTs are made of carbon atoms to SP2 hybrid-based, mixed with SP3 hybrid built into the ideal structure, it can be seen as a sheet of graphene rolled into a cylinder. Therefore inevitable graphite excellent intrinsic properties: such as heat transfer, electrical conductivity, heat resistance, corrosion resistance, thermal shock resistance, lubricity, and biocompatibility, such as a series of excellent performance. In conclusion, CNTs unique structure gives superior performance and broad application prospects

Abstract: Due to the unique properties of CNTs its own scientists called a "super fiber" has an attractive prospect in the high-tech fields. In recent years, the research center of gravity of the CNTs composites have been transferred to the polymer / CNTs composite materials, and has made great progress. CNTs and polymer composite, CNTs from nanometer to the actual operation of an effective and efficient use of the unique properties of CNTs can be achieved with the advantage of raw materials to complement or strengthen. Polymer composite materials have broad application prospects in information materials, biomedical materials, high-performance structural materials, multifunctional materials.

Abstract: The supercritical fluid impinging technology combined with fluidized bed (SFIT-FB) process is a novel technique to prepare microcapsules. The process was performed using ultra-fine glass beads as the core particle and paraffin the coating material. The influences of operation parameters, including the pressure and the temperature of mixing vessel and the impinging distance on the microcapsule morphology, size distribution and coating rate were investigated. The microcapsule characteristics could be controlled by adjusting the operation conditions. A number of techniques were used for the characterisation of the microcapsules. A scanning electron microscope (SEM) was used to examine the morphology of particle surface. A laser particle size analyzer (LPSA) was used to measure the particle size distribution, and differential scanning calorimeter (DSC) measurements were conducted to determine the apparent coating rates of microcapsules. The advantages of SFIT lies in enhancing the mass transfer and heat transfer, which prevent particles agglomeration.

Abstract: The tetragonal phase CuInS₂ nanoparticles were synthesized by the reaction of Cu(Ac)₂, InCl₃·4H₂O and thioacetamide by hydrothermal method at 200 °C for 6 h in pH 1. The products were characterized by X-ray diffraction, energy-dispersive X-ray spectrum, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Experimental results indicate that reaction temperature and the pH of solution are the important factors in the formation of CuInS₂. The SEM and TEM results illuminated that the CuInS₂ was composed of so many nanoparticles.

Abstract: CSCNT is a new type carbon nanotube, which has better physical and mechanical properties than the traditional materials. In this study, the effect of the dispersion and concentration of cup-stacked carbon nanotubes on mechanical properties of the CSCNTs/epoxy nanocomposites were investigated. The epoxy resin system used in this study was a two component (resin and harder) Prime 20. The CSCNTs were dispersed into the Prime 20 by ultrasonic agitation and mechanical mixing together. And the morphologies of the fracture surface of CSCNTs/Prime 20 nanocomposites were observed by scanning electron microscope (SEM); damping behaviors of the nanocomposites were studied by DMA at frequency domain.

Abstract: The Pr-TiO₂ photocatalyst samples were prepared by sol-gel method for improving the photocatalytic activity of TiO₂. The resulting materials were analyzed by XRD, SEM, TEM, and XPS. The photocatalytic activity of the catalysts was evaluated by degradation of methyl orange under UV irradiation. It was found Pr doping retard the growth of crystalline size and the phase transformation from anatase to rutile. Praseodymium doping could bring about remarkable improvement in the photoactivity. This high activity was attributed to produce the lattice distortion and inhibit efficiently of the recombination of the electron-hole by Pr³⁺.

Abstract: In the dual-phase model of interacting nanoparticles stretching leads to a decrease in both coercive force H_c and saturation remanence I_rs , and compression — to their growth. Magnetostatic interaction between particles also decreases both H_c and I_rs . Theoretical analysis was carried out in the framework of the dual-phase system of interacting particles on the example of nanoparticles γ-Fe₂ O₃, epitaxially coated with cobalt.

Abstract: In this paper the interfacial cohesive law of composite for single-wall carbon nanotubes (CNTs) and single crystal metal is characterized by van der Waals force, and the new interfacial cohesive law is established. The van der Waals force is sensitively related to the distance of atoms, therefore single crystal metal is delaminated according to the structure of crystal lattices that the metal atoms of same distance to CNTs are divided into one layer, and a series of parameters are obtained. The analytical expressions of the new cohesive law are useful to studying the composite interface between CNTs and single crystal metal, and can give the macro properties of the composites accurately.

Abstract: As a new type of materials, carbon nanotubes (CNTs) have been intensively studied due to their outstanding properties. Dielectrophoresis (DEP) is an effective method to assemble CNTs across a pair of electrical conductors for various applications. In DEP, CNTs suspended in dielectric liquid medium suffer a force imbalance due to induced dipole moment when subject to an externally applied non-uniform electric field, and move towards and finally deposit onto the electrode region. As a model plays a critical role in the numerical study of the DEP process, this paper introduces the theoretical background of DEP and basic DEP models based on the effective dipole moment method which has been widely accepted in the study of DEP. Particularly, the DEP force calculation methods developed recently for improved precision using these basic models are presented and discussed. A DEP model with high computing accuracy helps precisely predict a DEP process.

Abstract: Order nanopore arrays were made by a two-step anodization process. The effect of temperature on the order of nanopore arrays was studied. The result shows that the order is bad when the temperature is too high or too low. Then deposit Ni nanowire arrays in nanopores of AAO templates by direct current deposition. Nanowires deposited in AAO template have uniform length and thickness and the shape of nanowires is the same with that of nanopores. And the growth of the nanowires is from the bottom of the nanopores. Finally, the effect of pore diameter on activation energy of nickel deposited in nanopores was studied. The results show that the smaller the pore diameter the smaller the reaction activation energy, that is more conducive to the reaction.