Materials Science Forum Vols. 809-810

Abstract: Graphene oxide (GO) is typically synthesized by graphite powder under strong oxidizing reaction, possessing with the same set of functional groups: epoxy and hydroxyl in basal plane and carboxyl and hydroxyl groups existence on the flake edges which endow GO with amphipathy. GO and its functionalized derivatives have been successfully tested in many domains, such as polymer composites, biosensors, drug delivery systems, etc. In this paper, GO was prepared by a modified Hummers method employing improved process (preparation and separation), aiming at industrialization with the lowest cost. Moreover, some novel functional groups with different properties were controlled chemically grafted onto GO to modify the wettability and reaction activity with other materials. The hydrophobicity and the thermal property of graphene oxide were enhanced by chemical functionalization.

Abstract: Nowadays, how to deal with fiber reinforced plastic (FRP) residue becomes very difficult. In this paper, the characteristic of the production technology of epoxy based artificial granite was considered. Epoxy resin, FRP residue, granites and fillers were used on the study of adding FRP residue and epoxy based artificial granites of different proportion were prepared. They were prepared by casting moulding under the normal pressure and temperature. Flexural and compressive strength of the artificial granites were studied. SEM was used to observe the internal microstructure of artificial granites. Meanwhile, effects of different granularity and content of FRP residue on the properties of artificial granites were discussed.

Abstract: A supported photocatalyst zinc phthalocyanine-calcium alginate gel beads (Zn-MPc-SA) was prepared through the mixture of water-soluble zinc phthalocyanine (Zn-MPc) and sodium alginate was drip into 5% (w/v) CaCl₂ solution. The Zn-MPc-SA was characterized by IR. Methyl orange was selected as a substrate to investigate the photocatalytic activity of Zn-MPc-SA. The results shown that: the surplus of methyl orange was 22.05% at the condition of pH 3, methyl orange 10mg/L 25mL, H₂O₂ 50μL, Zn-MPc-SA 0.1460g and visible light irradiation for 3h. Zn-MPc-SA remains efficient in repetitive test cycles with no obvious degradation of catalytic activity. The reaction mechanism was likely to involve free hydroxyl radicals.

Abstract: Through numerical simulation of temperature field and pressure field in synthesis of SiC by carbothermal reduction method, the variation law of temperature and pressure with time in furnace was studied. Research results show that the high temperature isothernal face expands outside gradually with the prolong of the synthesis time, so the temperature field area compatible to the production of SiC increase gradually, but too long synthesis time not only increase energy consumption, but also generate SiC product yield decreased. Compared with single heat furnace, the pressure is comparatively more uniformity in three-heat-source and the pressure is 140~200kPa, which is useful for synthesis of SiC and can prevent furnace spewing. At the bottom of single heat furnace should pay attention to charge ration when charging, adding a little sawdust can increase the porosity and release pressure.

Abstract: There is a lot of glass fiber reinforced plastic (FRP) waste every year. Its low utilization rate and serious secondary pollution cause many problems. In this paper, FRP waste was added to enhance unsaturated polyester resin based artificial marble. The effects of FRP waste content and its particle size on the mechanical properties of artificial marble were discussed. Results show that the FRP waste content and its particle size are closely related to the mechanical properties of artificial marble. The artificial marble with FRP waste particle size of less than 0.075 mm and content of 12.5 wt % got the best mechanical properties, whose flexural strength was 23.72 MPa and compressive strength was 79.13 MPa, increased by 75.8 % and 128.1 %, respectively, compared with the strength of artificial marble with no FRP waste.

Abstract: This FePO₄ precursor was synthesized from Fe (NO₃)₃·9H₂O, NH₄H₂PO₄ ,different ligands by liquid precipitation route. Effects of different ligands value on the synthesis of FePO₄ precursor were studied. The phrase, structure and morphology of FePO₄ were characterized by XRD and SEM . The results showed that the structure and morphology of composite materials are dependence on synthesis process and complexant. After being added with different ligands, FePO₄ precursor’s morphologies have significant differences. Iron phosphate can produce the pure phase after calcinations. Keep it under 85°C for three hours after adding the citric acid and ammonium oxalate by liquid phase precipitation.When the concentration is 1.0 mol/L, PH = 1.5 ,we get flaky microspheres which are about 8 um. After being calcinated under 700°C for 2 hours, we get pure iron phosphate finally. The properties of micro ball with high specific surface area and tap density make FePO₄ precursor has important applications in many ways.

Abstract: This paper summarized the basic properties and preparation methods of ultrafine powder, introduced the present situation and progress of ultrafine powder classification technology at home and abroad, also pointed out the application of ultra-fine powder material in the mold manufacturing, biomedical, electronic information, fine ceramics, food industry and coatings.

Abstract: This paper focus on choosing the optimum forming temperature, drawing speed and installing the appropriate apparatus to control the thickness and shrinkage in the process of drawing flexible glass. The results showed that when the temperature of the glass was raised from 990K to 1100K, the thickness of the glass increased at a fixed drawing speed. As the drawing speed of the glass was increased from 6m/h to 21m/h, the thickness of the glass decreased while the shrinkage of the glass increased at a fixed drawing temperature. The optimum forming temperature ranged from 1025 to 1050K and the optimum drawing speed was 21m/h.At the same time, in order to get a suitable size of flexible glass, the pull-edge machines and cooling devices were installed in the drawing apparatus to control the shrinkage of glass.

Abstract: A new Diels-Alder Adduct of C₆₀ with 1,1’-biindene (CB) has been synthesized. The Langmuir trough study of this new fullerene derivative indicates that floating film could form monomolecular thick film at the air/water interface at lower concentration, and can be well transferred the floating mixed CB and arachidic acid film onto substrates using the Langmuir-Blodgett (LB) technique. In the case of the mixed film, high quality films with thickness of up to 50 layers could be readily built up. The absorption variation with film thickness at 255nm was measured, indicating good LB deposition up to 50 layers.

Abstract: A new kind cobalt tungstate in Co₄W₆O₂₁(OH)₂·4H₂O was smoothly synthesized by microwave hydrothermal process lasting for 80min at 190°C, in which Co (NO₃)₂·6H₂O and Na₂WO₄·2H₂O of analytical grade were selected as raw materials as well as the pH values adjusted from 3 to 5.5. Furthermore, the phase structure and the morphology of target products were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Additionally, the absorption spectrum of these samples was detected by UV-Vis spectrophotometer. The results showed that the cobalt tungstate in Co₄W₆O₂₁ (OH)₂·4H₂O structure belonged to the cubic crystal system with the lattice constant of 12.858Å and its micro geometric configuration tended to be rhombic dodecahedron. On the condition of pH value at four is best for the propagation of crystals. Moreover, in the absorption spectrum it is indicated that the band gap width of this materials equaled to 3.18eV at pH=4 while 3.81eV at pH=5.