Applied Mechanics and Materials Vols. 182-183

Abstract: UV ink has many advantages such as less pollution, high curing speed, saving energy, so it has been widely applied in traditional printing and emerging digital printing. In this paper, the two curing principles in UV ink which are free-radical curing and cationic curing, are discussed and compared, and the factors that affect the curing rate are analyzed through the comparing experiment of the curing rate. In the last, the selection principle of photoinitiator is established by means of analyzing and comparing curing rate when various photoinitiator or photoinitiator combinations is used in UV-cured ink. These studies have certain significance for improving the curing efficiency of UV ink and its application.

Abstract: α-Al₂O₃ platelets were prepared in the interface of Na₂O-CaO-SiO₂ glass induced by Al. Phase identification was accomplished by X-ray diffraction analysis. The morphology of the platelets was observed using an Environmental Scanning Electron Microscopy (ESEM). The changes for the mixtures of the Al powders and the glass powders that occurred during heating were characterized by a combination of differential scanning calorimetry (DSC) and thermalgravimety(TG) on a multi-functional instrument. Confirmed by XRD and ESEM, at 1200°C, the prepared platelets have mean diameters between 400nm and 1000nm. Most of them are aggregated and part of them through intergrowth. The crystals develop from the interface between glass and Al, and can form good moistening with the glass matrix. DSC/TG shows that γ-Al₂O₃ formed by oxidation of Al, transforms into α-Al₂O₃ and grow into the platelet α-Al₂O₃ crystals owing to the molten Al and the molten glass. On the other hand, part of the molten Al erodes into the glass and makes the deviation of the Na₂O-CaO-SiO₂ ternary system into Na₂O-Al₂O₃-SiO₂ ternary system, resulting in the formation of NaAlSiO₄.

Abstract: α-Al₂O₃ platelets were prepared in the interface of Na₂O-CaO-SiO₂ glass induced by Al. The morphology of the platelets was observed by Environmental Scanning Electron Microscopy (ESEM). The platelets are irregularly shaped at 720°C for 30mins and share mean thickness of 200nm. EDS shows that the platelets are rich in Si, reasonably due to the formation of Al-Si eutectic. At 1200°C, the prepared platelets have mean diameters between 400nm and 1000nm, most of which are aggregated and part through intergrowth. The crystals develop from the glass and can form good moistening with the glass matrix.

Abstract: Poly (aminohexylaminomethyl/phenyl) silsesquioxane (PAHAMPSQ) microparticles with diameter of 350 nm were synthesized by the hydrolytic condensation of aminohexylaminomethyltriethoxysilane (AHAMTES) and phenyltriethoxysilane (PTES) in the presence of H2O by using tetraethylammonium hydroxide (TEAOH) catalysts. PAHAMPSQ containing both aminohexylaminomethyl and phenyl groups were confirmed from FT-IR, TGA. XRD patterns indicate that a certain ordered structure existed in PAHAMPSQ molecules. Contents of amino of PAHAMPSQ were determined by elemental analysis. SEM images show both granular and flake exist in PAHAMPSQ microparticles. Yield of PAHAMPSQ in different AHAMTES/PETS molar ratios was about 80%. PAHAMPSQ offers the potential utility as building blocks for divers and novel organic/inorganic materials.

Abstract: This study employed a new modeling technology for lazurite. The related mechanical properties are explored, including the surface roughness, fragility and its morphology. It is found that the properties were improved; for example, the average roughness is reduced from 10.93m to 0.93m and the toughness is increased. We attribute the increase of toughness to a fine morphology with the new technology. Also it cost down 72%.

Abstract: Hydroxyapatite (HA) was synthesized in presence of 20wt% m-ZrO₂ by solid state reaction between tricalcium phosphate(TCP) and Ca(OH)₂ at 1000 °C for 2h. Similarily, Fluorine hydroxyapatite(FA) was synthesized using tricalcium phosphate and calcium fluoride as raw materials at 1000 °Cfor 3h. The as-prepared HA was mixed with 10%,25%,45%,55%,70wt% FA and the mixture was sintered at 1000°C-1400°C for 2h. The main phase and bulk density was measured. The results show that when the relative amount of FA to HA increased, the decomposition of the composite is decreased gradually because of the formation of thermally stable FHA solid solutions. Low temperature would effect the exchange of ionic between FA and HA,while high temperature would impact synthesis of composites, because high temperature would lead to dissolution of HA ,which has to react with FA. Increase the content of HA would be advantage for synthesis FHA-ZrO₂ composite.

Abstract: Nanometer ZnO/SnO₂ powder was prepared by coprecipitating method with SnCl₄•5H₂O, ZnNO₃•6H₂O, HCl, NaOH as raw materials. Influence of heat treated temperature on the photoactivating property and structure and material phase of nanometer ZnO/SnO₂ (ZnO/SnO₂=4/1(mol ratio)) compound photocatalyst powder was studied by X-ray diffraction (XRD) and transmission electron microscope(TEM) and the degradation of methyl orange solution as a reaction model. The results show that the photoactivating activity of ZnO/SnO₂ powder starts increasing and then decreasing when heat treated temperature increases. The photoactivating activity of ZnO/SnO₂ powder is maximum, particle size is 20-30 nanometer and dispersion is good when heat treated temperature is 650°C. The photocatalytic activity of ZnO/SnO₂ powder gradually reduces, dispersion is not good and there is Zn₂SnO₄ crystal phase when heat treated temperature is above 750°C.

Abstract: Fe and Co and Cr doped nanometer ZnO powder was prepared respectively by coprecipitating method with ZnNO₃•6H₂O, HCl, NaOH, FeCl₃•6H₂O, CoCl₂•6H₂O, CrCl₃•6H₂O as raw materials. Influence of Fe and Co and Cr doped amount on the photoactivating property of nanometer ZnO photocatalyst powder was studied respectively by methyl orange solution as a reaction model. The particle size and dispersion of Fe-doped ZnO powder was characterized by transmission electron microscope(TEM). The results show that the photoactivating activity of nanometer ZnO powder starts increasing and then decreasing when Fe or Co or Cr doped amount decreases.The photoactivating activity of nanometer ZnO powder is maximum when Fe or Co or Cr doped amount is 0.2 wt.%, the degradation rate of methyl orange is 60.79%, 52.56%, 53.91% after ultraviolet light for 50 minutes, respectively. When Fe doped amount is 0.2wt.%, the degradation rate of methyl orange is the highest, the degradation rate of methyl orange is 60.79%, particle size is 20-30 nanometer and dispersion is good.

Abstract: Different contents of carbon fiber were employed as reinforcement for Polyoxymethylene (POM) composite. All filled and unfilled POM composites were tested against CGr15 ball and representative testing was performed. The effects of carbon fiber content on tribological properties of the POM composites were investigated. The worn surface morphologies of pure POM and its composites were examined by scanning electron microscopy (SEM) and the wear mechanisms were discussed. Results show that all filled polyimides have superior tribological characteristics to unfilled ones. The optimum wear reduction was obtained when the content of carbon fiber is 15vol%.

Abstract: SiC nanoparticles were treated by hydrofluoric acid (HF) and then put into the formulation of tread compounds of tire. After being mixed fully in the open mill and vulcanized in the sulfuration machine, some rubber nanocomposites filled with SiC nanoparticles were finally prepared out. The SiC nanoparticle reinforced rubber composites were observed by Scanning Electron Microscope (SEM). It was found that SiC nanoparticles show good uniformity of dispersion and unobvious agglomeration of particles in rubber matrix after short-time treatment by HF, while they show bad uniformity of dispersion and obvious agglomeration of particles in rubber matrix after long-time treatment by HF.