Advanced Materials Research Vols. 785-786

Abstract: The two-mode phase field-crystal (PFC) method is used to simulate the nanograin growth, including the grain growth in different sets of crystal planes, the grain boundary structure with mismatch, the grain orientation and also the incoherent grain boundary in two dimensional plane. It is obviously observed that there are dislocation structures in nanograin boundary due to mismatch and misorientation of grains. These simulation results can not only be used in artificial controlling the grain boundary of nanograin, but also is of significant for designing new nanograin with a good grain boundary for structure materials.

Abstract: Fluorescent crossbar arrays and microropes of fluorescein/PMMA and rhodamine B/PS composite nanofibers have been fabricated via centrifugal electrospinning, respectively. The morphology and structures were measured by SEM and fluorescence microscope. The two as-spun fluorescent structures have potential applications in fluorescent security, fluorescent detection, and so on. By regulating the number of the nanofibers consisted in the microropes, the fluorescence intensity of the microropes can be manipulated, as well as the mechanical property of individual nanofibers, which can be calculated easily by testing that of the whole microrope.

Abstract: Using MgCl₂·7H₂O as the starting material and NaF as precipitating agent, nanoMgF₂ powder were prepared by sonochemical method. Morphological structure of the particle is characterized by means of XRD and SEM, TEM and Flourier Transition Infrared Spectrum. The influence factors, such as reactant concentration, reaction temperature and ultrasonic frequency were discussed. The optimum sysnthsis conditions was acquired, such as that the molar ratio of [F-] and [Mg²⁺] is 1/7.5, the reaction time 2h, the reaction temperature 80°C, the ultrasonic frequency 80kHz.

Abstract: Inlaid multi-wall carbon nanotubes modified graphite electrode (MWCNTs-GE) was fabricated, combined with Reline Ionic Liquids which possess high conductivity and wide electrochemical window, the electrochemical behavior and determination of Rutin was investigated by cyclic voltammetry and differential pulse stripping voltammetry. The result shows that the oxidation peak current of rutin increased obviously at the inlaid multi-wall carbon nanotubes modified graphite lectrode and in the Reline Ionic Liquids compared to that at the bare graphiteelectrode (GE). In phosphate buffer solution (pH=6.3), one pair of redox peak of rutin was obtained by cyclic voltammetry with 0.32 V of E_pa and 0.24 V of E_pc. The oxidation peak current value was linearly related to the concentration of rutin in the range of 2×10^-6~3×10^-5 mol·L^-1and the detection limit was 9.4×10^-7 mol·L^-1 . The average RSD of rutin was 4.0%. The average recovery was 100.2%. The inlaid multi-wall carbon nanotubes modified graphite electrode and the Reline Ionic Liquids had the function of electrocatalysis to oxidation of rutin obviously.This method is reliable, fast and convenient, sensitive and can be used for the determination of the content of rutin.

Abstract: A novel PMMA-ZrO₂ composite (PZC) was prepared by resin infiltrated to ceramic method. The composite mechanical properties were evaluated and correlated to its microstructure. Partially sintered zirconia ceramics (PSZC) were made by isostatic pressing and partially sintering. Subsequently, the PZC was prepared by vacuum infiltrating prepolymerized MMA into PSZC, followed by in-situ polymerization. When PSZC-70% was used as the matrix, the bending strength, elastic modulus, and fracture toughness of the prepared composite i.e PZC-70% were 202.56±12.09 MPa, 58.71±3.98 GPa, and 4.60±0.26 MPa·m^1/2, corresponding to 25.69%, 23.31%, and 169.01% improvement, respectively, in comparison with the control matrix. Among them, the fracture toughness improvement was the most prominent. According to SEM images of the fracture surfaces, each pore of zirconia skeleton was filled by organic resin contributing to the bending strength improvement. These weak interfaces between zirconia skeleton and organic resin absorbed energy and terminated the growth of microcracks which might be responsible for significant improvement in fracture toughness. This PZC material is anticipated to be a new member of the dental CAD/CAM family.

Abstract: The nanosized channels of SBA-15 molecular sieves were used as template and arsenano-III (ASA-III) was trapped inside the SBA-15 molecular sieves by means of liquid grafting method. The prepared nanocomposite materials were characterized by the powder X-ray diffraction, low temperature nitrogen adsorption-desorption and solid diffuse reflectance absorption spectra. The powder X-ray diffraction indicated the structure of the (SBA-15)-(ASA-III) still remains two-dimensional hexagonal mesostructrure. The low temperature nitrogen adsorption-desorption research showed that the ASA-III was present on the inner surface and partially occupied the channels of the molecular sieve. The UV-Vis solid state diffuse reflectance absorption spectra of the prepared composite materials showed the steroconfinmment effect of the host SBA-15 channels on the guest ASA-III and the guest was in the channels of the SBA-15 host. Luminous spectra showed that the prepared (SBA-15)-(ASA-III) nanocomposite materials have the investigating optical properties.

Abstract: Fe₃O₄ nanoparticles modified by a certain amount of oleic acid under in-situ processing were synthesized by precipitation method through dropwise adding aqueous solution of ammonia to mixed solution of Fe (II) and Fe (III) salts. Furthermore, Fe₃O₄/PMMA magnetic polymer microspheres were prepared by the emulsion polymerization method, which properties were characterized by the infrared spectrum, thermogravimetry analysis and scanning electron microscopy.

Abstract: The template method combined with sol-dipping deposition or sol-electrophoresis was used to prepare titania (TiO₂) nanowires with shape of rod or string of beads. The SEM was used to characterize the surface and cross section of the TiO₂ nanowire arrays. With parallel orientation, the nanowires were uniformly distributed.

Abstract: Some carbon nanomaterials have been proved to be able to improve the PCR amplification efficiency. If used in quantitative real-time PCR (qPCR), these nanomaterials must be tested whether fluorescence processing is interfered after they are added in the PCR system. In this study, 76 different carbon nanomaterials were tested in SYBR Green I-based qPCR, and the results demonstrated that about half carbon nanomaterials tested in this study could alter the PCR amplification profile probably due to the fluorescence quenching. Surprisingly, lower concentrations of nanomaterials led to more slight interference with the melting temperature.

Abstract: The surface binding energy between the polyimide(PI) and zinc oxide (ZnO) have been simulated using the molecular dynamics theory.The PI / ZnO model has been established by using Forcite program package of Materials Studio software.The total atoms number about 300 million, the radius of the nano-ZnO cluster model have five groups are respectively 0.5 nm, 1 nm, 1.5 nm, 2 nm, 2.5 nm.The effect of different particle size of nano-ZnO on surface binding energy in PI / ZnO composites was investigated. The relationship between the surface binding energy of PI / ZnO composites and the nano-Zno radius, the maximum of surface binding energy were obtained. The computed results show that the intermolecular bonds between nano-ZnO and PI are mainly van der waals bonds.And the surface atomic number of nano-ZnO increases along with the increasing of nano-ZnO radius, indicating that the increasing of contact surface between the nano-ZnO and PI, which lead to the surface binding energy increases, the total energy lower and the system more stable.