Advanced Materials Research Vol. 465

Abstract: We report the fabrication of a tin nanoparticles coated anode in graphene (SnO2 /graphene) for lithium-ion batteries. As an anode material for Li ion batteries, it has 806mAhg-1 and 683mAhg-1 capacities for the first discharge and charge, respectively, which is more than the theoretical capacity of tin oxide, and has good capacity retention with a capacity of 606mAhg-1 after 30 cycles.

Abstract: Hard and superlight thin films laminated with boron carbide have been proposed as candidates for strategic use such as armor materials in military and space applications. We prepared Al-Mg-B films by sputter deposition on Si (100) substrates with one AlMgB14 target. The films were characterized by X-ray diffraction, atomic force microscope, GD-OES spectroscopy. The results show that films of AlMgB with different compositions have been deposited by changing the target power and deposition temperature.The influences of substrate temperature and sputtering power on the quality of the films are discussed.

Abstract: Geometry structure, electronic structure and electronic transport properties of saturated hexagonal single crystalline GaN nanowires in the [001] growth direction have been investigated based on generalized gradient approximation (GGA) of density functional theory (DFT) and non-equilibrium green's function (NEGF) method. The results show, there is a contraction of the bond lengths of the saturated GaN nanowires after optimization; the nanowires have direct band gap, and band gap decreases with the increase of the cross section of nanowires; the electronic density of state and electronic transmission spectra of two-probe system have their own pulse-type sharp peaks with almost the same location of electron energy; the curves of I-V characteristics of the three saturated GaN nanowires are symmetric over the entire bias-voltage range, and they are semiconducting.

Abstract: In this paper, we report on fabrication and physical properties of carbon microcoils, which are prepared by a chemical vapor deposition (CVD) process with Ni-catalyzed pyrolysis of acetylene, and characterized by a scanning electron microscope, a transmission electron microscope and an infrared spectrometer. The dark electrical conductivity of an isolated carbon microcoil is about 81 S/cm at room temperature, and its temperature dependence follows three-dimensional Mott variable-range hopping (VRH) model. Particularly, evident photocurrent is observed in the carbon microcoil upon cameral flash illumination. In addition, it is found that the surface of microcoil film is hydrophobic, showing a large water contact angle of about 135°. These results indicate that carbon microcoils have excellent physical properties, and can be used as optoelectronic and reinforced materials.

Abstract: The aim of the present study was to assess the effect of nano-biphasic calcium phosphate (nanoBCP) scaffolds on acute alveolar bone defects in beagle dogs by micro-computed tomographic imaging (μCT). Alveolar bone defects were surgically created bilaterally at the buccal aspects of the upper second premolars in four beagle dogs. After root conditioning with ethylenediaminetetraacetate (EDTA), nanoBCP was randomly filled in the defects and nothing was put into the contralateral defects as controls. Dogs were killed at the 24th weeks. Specimens were scanned and reconstructed though μCT. The results revealed that much new alveolar bone formed in the defects in the nanoBCP groups while no new alveolar bone formed in the controls. The present results indicate that PBCP may enhance alveolar bone regeneration in acute-type labial dehiscence defects.

Abstract: Liquid marbles are hydrophilic liquid drops encapsulated with hydrophobic powder materials. The liquid marbles have potential applications in drug delivery, water purification, ferrofluidic device and sensor microfabrication. In this work, a new type of polytetrafluoroethylene nanoparticle (PTFE-NP) liquid marbles were fabricated successfully using mixing method. The morphology of the formed liquid marbles was characterized under different conditions, and novel properties of the PTFE-NP liquid marbles were investigated and demonstrated.

Abstract: There have much study about thermo-responsive nanogels,which exhibit temperature-controlled volume phase transitions.There have been few reports,however,of electrostatically neutral,thermosensitive nanogels with a high composition of hydrophilic monomer.Here,we describe the synthesis and characterization of a new class of nonionic copolymer nanogels based on N-ispropylacrylamide(NIPAM) and N,N-dimethylacrylamide(DMA),wich exhibit tunable volume phase transition temperatures.And increasing percentages of DMA in copolymer gels raises the LCST,and attenuates and broadens the volume phases transition.Through DLS, AFM and UV-Vis measurement it's size,shape and VPTTs.The character of nonionic NIPAM/DMA nanogels show it's tunable phase transitions promise to be useful for applicatipns in biotechnology and medicine.

Abstract: 4-Bromo-1, 8-naphthalic anhydride and N, N-Dimethylethylenediamine covalently modified silica nanoparticles were synthesized. It can be utilized as an adsorbent for Pb (II), showing excellent adsorption capacity. According to the Langmiur fitting, the maximum adsorption capacity for lead ion is up to 293.26 mg/g. And the adsorption percentage is greater than 90 % when the initial concentration is lower than 100 mg/l.

Abstract: Yb-doped ZnO optical waveguide thin films were deposited on sapphire substrates by radiofrequency (RF) magnetron sputtering technology, and then Er⁺ ions with the energy of 200 KeV were implanted into the as-deposited films, the implantation dose was 1×10¹⁵ ions/cm². Optical waveguide properties and film thicknesses were studied by prism coupling method. Film thicknesses, element components and Er⁺ ions range distrbution were studied by Rutherford backscattering (RBS) technique. The basic structure and phase of the films were studied using X-ray diffraction (XRD). The properties of optical frequency upconwersion were investigated by fluorescence spectrometer. The results demonstrated that the Yb-doped ZnO films with Er-implantation have planar waveguide structure and the waveguide properties were changed compared with the virgin ZnO films. The effective refractive indices of the films decreasing with the amount of Yb-doped concentration increasing. Yb concentration in films associated with targets but more than that in them. The films shown the classic structure of c-axis preferred orientation. The compounds of Yb:Zn and Er:Zn were appeared in the films. Inspired the films by 980 nm laser in room temperature, stimulated optical emission between 300~720 nm was not observed.

Abstract: ZnO waveguide films were fabricated on sapphire (001) and MgO (100) substrates by the radiofrequency (RF) magnetron sputtering technology using ZnO ceramic as the target. Properties of the films were investigated by prism coupling method, X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). The results demonstrated that the ZnO nano-films have planar waveguide structure and have nearly stoichiometric composition with c-axis preferred orientation growth. The growth rates of the films were slightly influenced by the substrates. The effective refractive indices of the films were smaller than the bulk material and were affected by substrates. The relationships between the average grain sizes, substrates, and film thickness were analyzed.