Advanced Materials Research Vol. 549

Abstract: The effect of a nucleating agent (NT-C) on the crystallization behavior of poly(lactic acid) (PLA) was studied. The melting and crystallization behavior and spherulitic morphology of the nucleated PLA were investigated by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarized light microscopy (PLM). It is found that the crystallization temperature and crystallinity increase, the spherulitic size decrease for the nucleated PLA. But the crystal structure of the nucleated PLA is not changed.

Abstract: The peroxyl radical scavenging abilities of fifty Chinese herbal medicines were determined accurately by an electron spin resonance (ESR) spin-trapping technique using 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) as a spin-trapping reagent. The peroxyl radical was generated by the thermolysis reaction of 2,2’-Azobis(isobutyronitrile) (AIBN) in the presence of the spin-tap DMPO and with or without sample. As a result of these studies, a strong scavenging ability of peroxyl radical was found in Chinese medicines for diseases of anti-aging and blood circulation.

Abstract: Transparent conductive ZnO:Zr thin films with different thicknesses were fabricated on glass slides by DC reactive magnetron sputtering from Zn:Zr targets consisting of Zn disk and Zr metallic chips in Ar+O₂ mixture gas. X-ray diffraction, four-point probe measurements, UV–vis spectrophotometers and thin film thickness tester were employed to characterize the structure, electrical and optical properties of ZnO:Zr films, respectively. The experimental investigations indicate that film thickness has an important effect on the crystal structure, optical and electrical properties of the deposited films.

Abstract: The TiC/Ni composite coating was prepared by Laser Cladding In-situ Synthesis on the surface of damper plate with Ni--Ti-Mo-C -LaF₃ powder．Microstructure and Wear resistance have been studied throughout EPMA、SEM and M—2000 Friction and Wear Tester．It was found that the microstructure got more homogenized grain fineness became finer, TiC distributed better and heterogeneous phase decreased, as adding moderate rare earth LaF3. When the content of LaF₃ was 1%, the highest microhardness was got. While the optimal wear resistance properties were obtained with 2% LaF₃. The laser cladding with excessive LaF₃ has more TiC particle segregation which induces hardness and wear resistance of cladding layer.

Abstract: In this paper, using environmental hormone dibutyl phthalate (DBP) in the contaminated foods as the template molecule, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate ester (EDMA) as cross linking agent, the molecularly imprinted polymer (MIP) was prepared on the silica surface. The MIP was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimeric analysis (TGA) and automated surface area analyzer. The property of adsorption was tested using static adsorption method in water phrase. The results of FTIR indicate that there are recognition groups in the microspheres after imprinting. TGA illustrates the silica gel surface has been coated with a layer of polymer after the synthesis reaction. And the MIP can bear the high temperature of 200 °C. The thickness of the imprinted polymer coated on silica gel surface is estimated via the pore size data is about 1. 5nm. The result of static adsorption experiment shows that the saturated adsorption capacity of the MIP was 8.940mg/g.

Abstract: Natural fibers possess many good characteristics, such as abundance, low cost, renewable, biodegradability and photo-degradability that made it a hot spot in exploiting current resources. Chemical modification is a new way to make efficient use of forestry and farming waste natural fiber resources. In this work, softwood fibers were modified by cyanoethylation with acrylonitrile. The influence of acrylonitrile dosage, reaction time, reaction temperature and the time immersed in sodium hydroxide solution with KSCN saturated on cyanoethylation were investigated. Fibers chemical structure and surface morphology before and after modification were characterized by FTIR and scanning electron microscope separately.

Abstract: In this paper, the processes on boron recovery from the liquid mineral resources (salt lake brine, oil- or gas-field water, and concentrate seawater) including the processes of precipitation, solvent extraction, fractional crystallization, ion exchange, and combined method at present were summarized, and the new trend in the future was also pointed out.

Abstract: Hydrotalcites consist of Brucite-like layers with positive charge and anionic compounds in the interlayer to form neutral materials. The general formula of hydrotalcite compounds (HTLc) was Mg-A1-HTLc. All samples were characterized by XRD, FT-IR spectra and TG. After calcination, the transformation of hydrotalcite structure can be characterized by vibration infrared bands corresponding to hydroxyl groups, octahedral layers and interlayer species. Moreover, the calcined samples show a relatively high surface area and total pore volume.

Abstract: Anodic alumina membranes (AAM) with nanopore arrays were prepared by one-step anodization of highly pure aluminum foil. Morphology, structure and composition of AAM were characterized by scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that AAM owned honeycomb structure which was characterized by close-packed arrays of columnar hexagonal cells, each containing a central pore normal to the substrate. The diameter of pores and the size of cells changed under different anodic conditions, such as temperature, concentration of H2C2O4 solution, voltage and time of anodization. The walls of AAM were composed of two strains of nanoparticles of alumina. Furthermore, the chemical composition of AAM was found to be amorphous alumina. The prepared AAM with nanopore arrays is a kind of ideal template for preparation of many one-dimensional nanomaterials.

Abstract: The adsorption of fuchsine by peanut husk, which was crosslinked by epichlorohydrin was studied with variation in the parameters of contact time, pH, initial fuchsine concentration and temperature. They were used for equilibrium adsorption uptake studies with fuchsine. The results indicate that adsorption equilibrium could be well described by both the Langmuir and the Freundlich isotherm equation. The adsorption followed the pseudo-second order model. The thermodynamic constants of the adsorption process were also evaluated, which suggest an endothermic adsorption process which runs spontaneously.