Advanced Materials Research Vols. 602-604

Abstract: Epichlorohydrin crosslinked starch microspheres (ECMs) were synthesized with soluble starch as a raw material and epichlorohydrin as a crosslinker. The characteristics of ECMs were investigated by Scanning Electron Microscopy (SEM) and Fourier Transform InfraRed spectroscopy (FT-IR).The drug loading and in vitro release properties of ECMs were studied using arginine as a model drug. The results indicate that ECMs have a spherical morphology with average diameter about 7μm. The drug loading studies show that after absorption for 1.5 h, the largest amount of drug (drug loading 31mg/g) is loaded when the quantity ratio of ECMs to arginine is 2. In-vitro release studies indicate that the ECMs are effective in controlled releasing arginine over an extended period of about 25 h.

Abstract: Lithium-doped zinc oxide(ZLO) thin films were deposited on glass substrates by sol-gel method.And then by controlling processing parameters such as the amount of doped lithium and stability, etc,Well-aligned ZLO nanorod arrays were successfully grown on substrates by hydrothermal method, where the substrates were spin-coated with seed layer.The experiments show the 5% Li-doped and diameter of about 50nm of ZLO thin films nanorod arrays has the best performance photoluminescence and surfactants can promote the growth of ZLO rod-like nano-structures and contribute to the formation of ZLO nanorod arrays with highly oriented.

Abstract: A multi-wall carbon nanotube modified glassy carbon electrode (MWCNTs/GCE) has been prepared. The electrochemical behavior of scutellarin at the modified electrode and its electroanalytical method have been studied. It was showed that in 0.20 mol/L Na2HPO4-NaH2PO4 buffer solution (pH=7.4) MWCNTs/GCE exhibited excellent catalytic and enhancement effect on the electrochemical oxidation of scutellarin, the sensitivity increaced 23 times compared with that at bare GCE. The measurement parameters were optimized. Under the optimal conditions, the linear range of scutellarin concentration was 4.0×10-6-1.0×10-4 mol/L (R=0.9991) with a detection limit of 8.2×10-7 mol/L(S/N =3), and the RSD for 4.0×10-5 mol/L scutellarin solution was 1.8% (n=11). This method was successfully used in the determination of scutellarin in injection and tablets.

Abstract: The object of this work is to investigate the interface and size effects on the structural phase transition of Nb nanoparticles (NPs) embedded in Cu matrix. By means of X-ray diffraction analysis and high-resolution transmission electron microscopy observation, it is found that higher coherency of the Cu/Nb interface benefits the occurrence of phase transition in Nb NPs with larger sizes. The sufficient conditions for the transition are: (1) the size of Nb NPs should be smaller than 8 nm; (2) the Cu/Nb interfaces should be semi-coherent or coherent. The experimental results are consistent with the predictions of Bond Energy model.

Abstract: Using sol-gel method, a series of nanocrystalline materials La_1-xAE_xCrO₃ (AE=Ca, Sr) were synthesized. Difference between Ca- and Sr-doped lanthanum chromites were investigated by carrying out differential scanning calorimetry (DSC), thermogravimetric analysis (TG), X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). It was found that the synthesis temperature (1-xCa_xCrO₃, and CaCrO₄ as the second phase (x≥0.2) at the room temperature. LSC is composed of single orthorhombic perovskite phase for x=0.1, while the orthorhombic and rhombohedral perovskite phases coexist for x=0.2, and only rhombohedral perovskite phase for x=0.3. Further studies showed that the maximum solubility of Sr was lower than that of Ca in lanthanum chromite.

Abstract: An OMMT (organic montmorillonite) was prepared by ion exchanging between Na-montmorillonite and cetyl trimethyl ammonium bromide (CTAB) and was applied to modify Dicyclopentadiene Dioxide Epoxy(R-122). FT-IR spectra showed that the organic molecules had intercalated into the layers of MMT successfully, X-ray diffraction illustrated that the spacing of layers of MMT increased from 1.43 nm to 3.85 nm. R-122 composite was prepared with this nano-organic montmorillonite. When the content of OMMT was 4.0% (wt%), the impact strenth of the composite reached to the highest(21.2 J/m), which is 92.7% higher than the pure R-122 . Morphology of the fracture checked by SEM, reveals a depth depended distribution which generated more new surface, thus can absorb more impact energy. Differential scanning calorimetry(DSC) showed that the thermal stability of the composite had improved compared with the pure resin. And what’s more, the improvement of toughness doesn’t hurt the resin’s heat resistance, it may provid a new way to prepare high performance R-122 composites.

Abstract: Silica micro-spheres were prepared from sodium silicate at room temperature with ethyl acetate as the precipitant. The effect of process parameters on the yield and the morphology of SiO₂ powders was systematically investigated and the optimum reaction condition was confirmed as follows: the concentration of sodium silicate was 0.6 mol/L, the total addition amount of the blend surfactants of PEG-1000 and sodium dodecyl benzene sulfonate (SDBS) was 2.1% and the blend ratio was 20:1, the addition amount of ethanol and ethyl acetate were 5.0% and 8.0%, respectively, the stirring rate was 600 rpm and the reaction time was 4.0 hours. The average particle size was 400 nm and the yield was 93.8% .The product was characterized by scanning electron microscope, Infrared Spectroscopy, and X-ray powder diffraction.

Abstract: Thermoplastics were prepared by melt blending using polypropylene [PP] and expended vermiculite ball-milled with VAE emulsion. The effect of vermiculite content and vermiculite particle diameter on the crystallization and mechanical property of PP were studied. The mechanical property of PP and the composites studied by using universal testing machine show that both mass fraction of vermiculite and particle size have consequences for mechanical property of PP, and when mass fraction of vermiculite and ball-mill 5 hours can acquire good mechanical properties. The two parameters are in agreement with morphology of the composites observing from the Scanning Electron Microscopy and polarized-light microscope. The results obtained from nonisothermal crystallization of PP and the composites, which were carried out using the differential scanning calorimetry technique, show that vermiculite with micro diameter block crystallization, while vermiculite with micro-nano diameter can induce crystallization and increase crystallization.

Abstract: The effect of cadmium ions and nanostructured carbon sorbent on limfodynamic and composition of lymph was studies. The experiments showed that prolonged poisoning of rats with cadmium chloride (per os) causes changes of biochemical composition and physic-chemical parameters of lymph and blood plasma. The accumulation was marked by of cadmium ions in the lymph nodes, where their concentration is increased 5-7 times of the original level. Using n nanostructured carbon sorbent «Ingo-2» reduces substantially negative effect of cadmium on limfodynamic and indicators of lymph.

Abstract: The oxidized multi-walled carbon nanotubes were prepared by a nitric acid treatment procedure, which were then used as additive in thin-layer chromatography stationary phases for resolution of ofloxacin, mandelic acid and 2-chloro-mandelic acid enantiomers. In a sharp contrast with pristine multi-walled carbon nanotubes/D-(-)-tartaric acid impregnated thin-layer chromatography plates, oxidized multi-walled carbon nanotubes/D-(-)-tartaric acid impregnated plates presented better enantioseparation effects for ofloxacin enantiomers.