Advanced Materials Research Vols. 785-786

Abstract: A nano-material named opal blended with polymer, then were added into slurry, after a series of special paper-making process, the rice paper releasing anion was successfully prepared by us. By test of SEM, we observed nano-structure morphology in the image of opal particle and rice paper sample. A series of mechanical properties had been tested as GB18739 or QB/T3515 standard. After testing of anion concentration, maximum of rice paper reached -9510cm^-3，meet the needs of human health. There is no doubt opal is a kind of environmental material for human health.

Abstract: The combined miniemulsion and solvent evaporation (MESE) method was employed to fabricate hydrophobic dye/polymer composite colorants in the present work. Using dynamic light scattering tests, the effect of the formulation variables on the size and size distribution of the prepared nanoparticles was examined. Transmission electron microscopy, UVvisible spectrophotometry, X-ray photoelectron spectroscopy, and elemental analysis results indicate that dye molecules or aggregates were successfully encapsulated in the poly (methyl methacrylate) matrix using the MESE method and the resulting composite colorant could be dispersed in water.

Abstract: This work presents the results of obtaining the sulfur nanoparticles, which can be used in agriculture as a fungicide. Sulfur nanoparticles were obtained by modifying the surface of sulfur using various surfactants including cetyltriammoniumbromide (CTAB), sodium dodecylbenzene sulfanate (SDBS) and Triton X-100 (TX-100). The size, crystal structure and morphology of sulfur nanoparticles were determined by methods as laser size analyzing (LSA), X-ray diffraction (XRD), scanning electron microscope (SEM). It was found that the nanoparticles had a sulfur monoclinic β-form struture, and their average size was in the range of 1000-1500 nm.

Abstract: Polishing powder based on CeO₂ is synthesized by a neutral precipitation method under the action of an additive, with Ce₂(CO₃)₃ as starting material and NH₄HCO₃ as the precipitant. The size distribution of CeO₂ particles is narrow-ranged and their morphology show a shape of polyhedral globules. They have a satisfied dispersion in water. The optimum characteristics are obtained under the conditions of followings: the mass ratio of F (in H₂SiF₆ ) to CeO₂ 7%, the molar concentration of additive A4 0.85mol/L, calcined at 850°C for 2 hours.

Abstract: The size and shape of gold nanoparticles controlled by pH was studied in the reacted solutions containing peptides (NH₂-Leu-Aib-Trp-Ome) as reducing agent. The resulting gold nanostructures were characterized by transmission electron microscopy (TEM), XRD and UV-vis-NIR spectra. Different shape of gold nanoparticles such as spheres, multipod and branch were prepared by changing the pH of solution. The resulting gold nanostructures may be have potential applications in the Surface Enhanced Raman Spectroscopy (SERS) and NIR-absorbing filters and coatings.

Abstract: A simple and cost effective method was reported for the synthesis of β-SiC nanoparticles with differernt morphologies using Taixi coal as carbon source and Fe (NO₃)₃·9H₂O, Co (NO₃)₂·6H₂O and NiCO₃·2Ni (OH)₂·4H₂O as additives, respectively. The structures and morphologies were characterized by XRD, FTIR, BET and SEM. The results show that SiC nanoparticles with lamellar structures were successfully synthesized at 1450 °C with NiCO₃·2Ni (OH)₂·4H₂O as an additive which are very scarce to our knowledge. whats more, the formation mechanism of lamellar structures SiC nanoparticles were also discussed.

Abstract: In the present study, controlled release characteristics of new nanosized PLA-Pluronic-PLA block copolymer vesicles comprising of amphiphilic poly (lactic acid) (PLA) and Pluronic block copolymers (PEO-PPO-PEO) have been evaluated as an oral insulin carrier. The mean size of vesicles was 78 nm for PLA-F127-PLA and 165 nm for PLA-P85-PLA copolymer. The mean insulin entrapment efficiency was 59.6% for PLA-P85-PLA and 26.4% for PLA-F127-PLA. The in vitro release characteristics of insulin from vesicles exhibited an initial burst in the range of pH 1.2-7.4 dissolution mediums. The presence of PLA-Pluronic-PLA vesicles improved the stability of insulin in the gastrointestinal fluids than that of the phosphate buffer solution (PBS) of insulin. More importantly, the released insulin from the vesicles maintained their biological activity. The results from this studies demonstrated that biodegradable PLA-Pluronic-PLA can self-assemble with insulin, form insulin-encapsulated vesicles, and is good carrier materials for oral insulin/protein delivery.

Abstract: The effect of grinding on the photocatalytic activity of commercial ZnO powder was explored using methyl orange as a model pollutant and the corresponding mechanism was discussed tentatively. The results indicate that the photocatalytic activity of the ZnO powder grinded decreases obviously in comprison with that of the ZnO powder untreated. This phoenomenon might be ascribed to the decrease of surface defects of ZnO induced by grinding, suggesting that the further treatment leading to the change of surface states of ZnO powder as a photocatalyst ought to be avoided.

Abstract: A simple method of melt blending was used to prepare PP, PP/IFR and PP/IFR/OMMT composites. The Flammability and mechanical property of the composites were investigated. Limiting oxygen index (LOI) tests and cone calorimetry results indicate that there are synergisms between IFR and OMMT. Incorporation of OMMT led to a further increase in LOI value of intumescent retarded PP samples when the addition amounts of OMMT are less than 2%. Cone calorimeter measurements demonstrate that the peak heat release rate (PHRR), average mass loss rates (AMLR) and fire growth rate index (FIGRA) of PP/IFR/OMMT composites are all less than that of PP/IFR30 when OMMT contents are less than 1.5% (including 1.5%).Char residues after cone calorimeter tests were investigated. Unlike the expansion char residue of PP/IFR, the char residues of PP/IFR/OMMT display a lower height and compact morphology, which are due to the barrier effect of OMMT. The presence of less than 1.5% OMMT can somewhat enhance the tensile strength and Izod impact strength of PP/IFR/OMMT composites. Larger OMMT amounts decrease the above mechanical properties.

Abstract: The titanium sol was prepared by depositing the organic titanium on glassy carbon electrode surface. Electrophoresis time and the applied voltage as well can markedly influence the electrochemical behavior of the nanoTiO₂ film. In contrast with bare glassy carbon electrode, the nanoTiO₂ film on glassy carbon electrode had a good electrocatalytic activity to dopamine (DA) and uric acid (UA) in PBS solution. The result showed that there was a linear relationship between the oxidation peak currents and the concentration of DA from 8.0×10^-6 to 4.0×10^-4 mol·L^-1 by differential pulse voltammetry (DPV) and there was a linear relationship between the oxidation peak currents and the concentration of UA from 8×10^-6 to 1.0×10^-3 mol·L^-1. This modified electrode was quite effective to detect DA and UA in simultaneous determination of these species in a mixture.