Advanced Materials Research Vols. 148-149

Abstract: The ability of porous nano-barium-stroutium titanate (PBST) to remove heavy metal (lead, nickel and zinc) ions by sorption from aqueous solution was assessed. The effects of process parameters such as pH, contacttime, regeneration conditions and the effects of common coexisting ions on heavy metal (lead, nickel and zinc) ions uptake were investigated. The results showed that the lead, nickel and zinc ions studied could be quantitatively retained at a pH value range of 5~8. The adsorption capacities of PBST for lead, nickel and zinc were found to be11 6.5mg•g-1, 4.8mg•g-1 and 8.3 mg•g-1, respectively. Desorption studies were carried out successfully with diluted HNO3 solutions. The results indicate that PBST can be used as an effective adsorbent for the treatment of wastewaters contaminated with lead, nickel and zinc ions.

Abstract: An allometrical scaling relationship between the solution concentration and the nanofiber diameter in bubble electrospinning was established. The scaling law was validated with experimental results using bubble-electrospun Polyvinylpyrrolidone (PVP) nanofibers at different concentration PVP solutions. The results showed that the average diameter of PVP nanofibers increased approximately exponentially with solution concentration in bubble electrospinning process. The experimental data agreed well with the theoretical predictions, and showed that the present model had high prediction accuracy.

Abstract: Titania nanotube arrays were synthesized via anodic oxidization of titanium foil in dimethyl sulfoxide (DMSO) solution containing 2 wt% HF and 3 wt% H2O at 40 V. The microstructure of the arrays was characterized with scanning electron microscopy (SEM). The results show that morphology of titania nanotube arrays is evidently influenced by the anodization time, and with the extension of oxidation time, the better morphology could be obtained. The possible formation mechanism of titania nanotube arrays has been discussed.

Abstract: In present work mechanochemical synthesis of fine dispersed MgAl-CO3 LDHs is based on the preliminary mechanical activation of mixture of magnesium hydroxide, aluminium hydroxide and sodium hydrogen carbonate in a planetary activator AGO-2, followed by the thermal treatment of activation products at a temperature of 90 . The Mg/Al molar ratio was discussed. The samples were characterized by x-ray diffraction, thermogravimetry, scanning electron microscope, and energy dispersive spectrometer. According to obtained data the interaction mechanism was proposed.

Abstract: Magnetorheological (MR) dampers are the semi-active control devices that use MR fluids to produce controllable dampers. In this paper, the design method of the cylindrical MR damper is established. Bingham model is used to describe the constitutive behavior of MR fluids subject to an applied magnetic field. The equation for the damping force is derived to provide the theoretical foundation for the design of the damper. Based on this equation the engineering expressions for the gap and effective length of the annular MR fluid between the piston and the outer cylinder are derived. The result shows that with the increase of the applied magnetic field strength, the damping force is increased. The dimensions of the gap and length can be calculated when the required damping force, the velocity of the piston, and the desired control damping force ratio are specified.

Abstract: Lead strontium titanate (PST) nanotubes were fabricated with sol-gel method on AAO template. Thermal evolution and phase transformation process of PST were characterized by Thermogravimetry and Differential thermal analysis (TG/DTA) and X-ray diffraction (XRD). It was found that PST began to crystallize at 560°C and became perovskite structure without other phases. The morphology and structure of PST nanostructures was characterized by SEM and TEM. The capacitor of AAO and PST-AAO compound aluminum foil annealed at different temperature were tested with precision impedance analyzer. It revealed that the microstructures of PST were polycrystalline nanotube array and the capacitor of compound aluminum foil was increased for PST existing in the AAO, which indicated that this compound method could improve the capacitor of aluminum foil effectively.

Abstract: M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were successfully prepared by the sol-gel method and solution phase reduction method, respectively. The crystalline and morphology of particles were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The composite coatings with SrFe12O19 ferrites and FeNi3 nanoplatelets in polyvinylchloride matrix were prepared. The microwave absorption properties of these coatings were investigated in 2-18GHz frequency range. The results showed that the M-typical SrFe12O19 ferrites and FeNi3 nanoplatelets were obtained and they presented irregular sheet shapes. With the increase of the coating thickness, the absorbing peak value moves to the lower frequency. The absorbing peak values of the wave increase along with the increasing of the content of FeNi3 nanoplatelets filling fraction. When 40% SrFe12O19 ferrites is doped with 20% mass fraction FeNi3 nanoplatelets to prepare composite with 1.5mm thickness, the maximum reflection loss is -24.8 dB at 7.9GHz and the -10 dB bandwidth reaches 3.2GHz.

Abstract: The influences of a thin InGaAs layer grown on GaAs(100) substrate before deposited InAs self-assembled quantum dots(SAQDs) were experimentally investigated. Scanning electronic microscope (SEM) measurements show that the InGaAs strained layer may release the strain between wetting layer and QDs, and then enlarge size of QDs. When the thickness of InAs layer is small, the QDs are chained. Temperature dependent photoluminescence (TDPL) measurements show that the PL peaks of InAs QDs with In0.1Ga0.9As show much more red shift compared with the QDs directly deposited on GaAs matrix, and PL integral intensity enhances as T rises from 50K to 90K. We attribute this enhancement to the small potential barrier between WL and QDs produced by the InGaAs stained layer.

Abstract: PbTiO3 microrods were successfully synthesized via a surfactants-free hydrothermal method. The powders were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and photoluminescent spectra techniques (PL). It was found that the precursor played a key role in the formation of PbTiO3 microrods.

Abstract: Intelligentization is the development direction of functional materials and the intelligentized concrete is the advanced stage of the development of concrete, which is the product of the intelligentized era. This paper aims at explaining the background of the intelligentized concrete, briefly describing the state of the field and the hot spot issue of three kinds of intelligentized concrete which is of unitary function, and looking forward to the development trends and prospects of the Intelligentized concrete.