DAI Jian-feng, GAO Jian-long, QIAO Xian-wu, WANG Qing, LI Wei-xue, DU Xiao-fang. Study of Conductivity and Percolation Effect on Orientated CNTs/PMMA Composites[J]. Journal of Materials Engineering, 2008, 0(10): 1-4,9.
The electrical conductivity and percolation thresholds of realigned carbon nanotubes(CNTs) composites have been simulated based on Effective-Medium Theory(EMA).The result reveals that electrical conductivity and the percolation threshold depend on the orientation,the aspect ratio and the structure of CNTs in the composite matrix strongly.Percolation thresholds can be concluded simply by computing the increased ratio of electrical conductivity with the content of CNTs.The simulated results are inosculated with the experimental results basically,and the discrepancy between simulated results and experimental results has been interpreted reasonably.
WANG Ji-hui, DONG Qing, LI Ying. Preparation and Characterization of Si/Al Composite Hollow Microspheres by Octylamine Templating[J]. Journal of Materials Engineering, 2008, 0(10): 5-9.
Si/Al composite oxide hollow microspheres were prepared by sol-gel route and using octylamine vesicles as core template,TEOS as silica source,aluminum isopropylate as aluminum source and hydrochloric acid as catalyst.The surface morphology,mean diameter,shell thickness and structure of Si/Al composite oxide hollow microspheres under different reaction time and temperature were examined and determined.The results showed that the mean diameter of Si/Al composite hollow microspheres increased with the promotion of reaction temperature and prolongation of reaction time,but was smaller than that of silica hollow microspheres under the same preparation condition.The as-synthesized Si/Al composite hollow microsphere had a mean diameter of 8-16μm,shell thickness of 2.18-3.61μm,specific surface area of 431-912m2/g and microporous structures with pore diameter around 1.2-2.0nm.The aluminum species in Si/Al composite oxide hollow microspheres was mostly in the form of alumina.
CAI Xiao-Lan. Researched the Collision Model of One Dimensional Nano-powder Zinc-flakes by the High-energy Milling[J]. Journal of Materials Engineering, 2008, 0(10): 10-11,15.
We applied to relations between the milling time and thickness、and D50 of zinc-flakes of high-energy Milling Use Benjaminm collision model.The model can also be applied to other one Dimensional Nano-powder and alloy in the high-energy Milling.Through established of the collision model,the relationship of various technical indicators can be calculated of powder,and it can be used to guidance of the research process and optimize the process.
JING Xiao-yan, KUANG Wei-wei. Preparation of Nano-ZnO and Rare Earth Composite Particles by Polymer Network Method[J]. Journal of Materials Engineering, 2008, 0(10): 12-15.
Composite powers of nano-ZnO with rare earth oxides were prepared by polymer network method using zinc nitrate and nitro-rare earth oxides as raw material,acrylamides as monomer,N,N′-methylene diacrylamide as network reagent.The average diameter of composite particle ranges from 17nm to 47nm.The structure,morphology,component and bonding mode on the surface of precursor particles were characterized by XRD,SEM,TEM,EDS and FT-IR.
XU Bin, WANG Min-jie, YU Tong-min, ZHAO Dan-yang. Study on Micro-scale Effect on Impact of Polymer Melt Wall Slip[J]. Journal of Materials Engineering, 2008, 0(10): 16-20,24.
On the basis of analysis of polymer melts wall slip mechanism and micro-scale effect on the impact of wall slip in micro channel,a micro-channel model of wall slip was developed by modifying the slip coefficient of the wall slip model constructed by Hatzikiriakos.With none-modified model and modified model,the wall slip velocity and the pressure drop in the 0.5mm diameter micro channel were carried out at different shear rate through numerical simulation.Compared with two different results,the results,which were calculated by modified model,showed that the wall slip velocity decreased but the pressure drop increased.In contrast to the pressure drop which was measured by test,the pressure drop calculated by modified model was closer to the experimental results.
YANG Ming-shan. In-situ Surface Polymerization Encapsulation of Nano-CaCO3 Particle[J]. Journal of Materials Engineering, 2008, 0(10): 21-24.
The organic-inorganic complex nano-particles with core-shell structure were prepared by in-situ emulsion polymerization based on fresh slush pulp of calcium carbonate(CaCO3) nanoparticles and acrylate polymer.The dispersion and encapsulation of nanoparticles were investigated by transmission electron microscopy(TEM),DSC,TGA and electron spectroscopy for chemical analysis(ESCA).The results showed that in the presence of nano-CaCO3 particles,the in-situ emulsion polymerization of acrylates was carried out smoothly,and polyacrylates successfully encapsulated on the surface of nano-CaCO3 particle to prepare the modified nanoparticles,breaking down nano-CaCO3 particle agglomerates.
LEI Wei-ning, ZHU Di, LI Dong-lin, LIU Liu, LI Ren-xing. Research on High-performance Micro-electroforming[J]. Journal of Materials Engineering, 2008, 0(10): 25-28.
The effect of the rare earth nano-La2O3 added to the basic sulfamate solution on micro-electroforming process was studied.The surface microstructure evolution and its properties of micro-electroforming layers were examined and analyzed by scanning electron microscopy(SEM) and other tester.The results showed that the cathodic polarization of the micro-electroforming process was increased due to occurring of nano-La2O3 special adsorption on electrode surface,which could result in crystal refining of electroforming layer.Moreover,the mechanical properties of micro-electroforming layers,such as micro-hardness and wear resistance could be improved substantially with the addition of nano-La2O3.
ZHENG Xiao-ping, ZHANG Pei-feng, HE De-yan, HAO Yuan. Simulation of Abnormal Effect in Film Groeth Using KMC Method[J]. Journal of Materials Engineering, 2008, 0(10): 29-31,34.
On the basis of the classic diffusion theory we have advanced a novel model,which consists of the basic micro-processes,and have simulated the growing process of surfactant-mediated epitaxial thin-film growth with the method of Kinetic Monte Carlo(KMC).The simulated results indicated that the adatoms easily aggregate to island seeds at the low temperature and the abnormal effect results from that the surfactant atoms are more easier to be activated and to diffuse than adatoms.Meanwhile,it was found that both surfactant atoms and adatoms would diffuse from one layer to another.The exchange rate is not constantly one,but is related with the substrate temperature,deposition flux,deposited depth and so on.
YUAN Xing-hai, XU Xue-yan. Study of Water Based Fe3O4 Magnetic Liquid Modified with Agar[J]. Journal of Materials Engineering, 2008, 0(10): 32-34.
Fe3O4 magnetic nanoscale water-based magnetic fluid was prepared by co-precipitation at the room temperature with polyethylene glycol,gelatin and agar as dispersant.The optimum conditions were as follows:1) Fe3+/Fe2+(mole ratio) was 1.70-1.75;2) the precipitant,25% ammonia water was used 20%-30%,under 35℃,pH10-11 and with a stirrer speed of 3000r/min for 1h;3) in the first package process with gelatin and agar,the optimum amounts was 0.050-0.060g/150mL at the temperature of 55-60℃ and pH of 9-11;In the first package process with polyethylene glycol,the optimum temperature was at 55℃ and with a stirrer speed of 3000r/min for 1h.Water-based magnetic fluid was characterized by transmission electron microscopy,infrared spectrum,spectrophotometry and gouy magnetic balance.The results showed that the introduction of dysprosium into magnetic fluid will increase significantly the magnetism.
LI Xiao-yan, LIU Zhi-hong. Study on Advanced Treatment of Pulp Mill Effluent with TiO2 Hydrosol as Photocatalyst Under Solar Radiation[J]. Journal of Materials Engineering, 2008, 0(10): 35-38,42.
The factors that affect the treatment of straw pulping wastewater have been investigated with the self-prepared TiO2 hydrosol as photocatalyst when fluorescent high pressure mercury vapour lamp or solar light act as light source respectively.The experimental results showed that the CODCr removal rate of straw Pulping wastewater is high at the optimized conditions especially under the solar radiation.Under the solar radiation,the CODCr removal rate can be up to 90% in 10min.meanwhile,the color of the wastewater can be eliminated effectively in the photocatalytic process.
ZHENG Xu-xu, YU Huang, YIN Zhong-yi, FANG Ming-jian, HOU Ke-shan, LI Xiao-hong. Catalytic Activity and Kinetic Equation of Nitrogen-doped TiO2 Nanoparticle for 4-Chlorophenol Under Visible Light[J]. Journal of Materials Engineering, 2008, 0(10): 39-42.
N-doped TiO2 nanoparticle was prepared through a sol-gel procedure using NH4Cl as the nitrogen source.The photocatalytic degradation yield of 4-chlorophenol and the removed yield of total organic carbon(TOC) were measured.The main influence factors including the calcination temperature,stirring speed,and pH value of 4-chlorophenol were investigated for the catalytic activity and kinetic equation of N-doped TiO2 under visible light(>400nm).The results showed that the N-doped TiO2 had obvious catalytic activity under visible light,when the calcination temperature was 400℃,stirring speed was quick and pH value of 4-chlorophenol was 4.6,the degradation yield of 4-chlorophenol was the maximum.As the irradiation time was 6h,the degradation yield of was 87%.The kinetic equation of photocatalytic degradation of 4-chlorophenol was corresponded to Langmuir-Hinshelwood equation.
YI Hui-yang, CHEN Fang, LUO Si-qing. PTC Effect of HDPE/CB-WMNTs Composites[J]. Journal of Materials Engineering, 2008, 0(10): 43-45,49.
The positive temperature coefficient effect and mechanical of a high-density polyethylene/carbon black-multi-walled carbon nanotube composites are reported.The results showed that,the PTC intensity of HDPE/CB-MWNTs composites with 1%(mass fraction,the same below) MWNTs is 8.3,and the room temperature resistance is only 1.2Ω·m;but for the 3% MWNTs,the composites PTC intensity reduced to less than 3 rapidly,and the room temperature resistance is little changed.SEM showed the conductive filler CB or MWNTs in composites is evenly distributed.The reasons of PTC intensity of HDPE/CB-MWNTs composite changes with the content of MWNTs were discussed.
WU Guang-ming, WANG Yi, JIN Li, HAN Bin, XING Guang-jian, JIANG Wei. Study of Photoluminescence Films of Carboxylic Acid Complexes with Europium Prepared with Spin-coating Spray Pyrolysis Method[J]. Journal of Materials Engineering, 2008, 0(10): 46-49.
Carboxylic acid complexes with europium were dissolved in DMSO to form solution.The temperature of spin-coating spray pyrolysis for preparing films was determined by TG as 120℃.The photoluminescence films of carboxylic acid complexes with Europium were prepared successfully through exploring the experimental parameters with home-made equipment.Radiating with 320nm UV and measuring of excited intensity of 633nm red light,the results showed that excited intensity is closed to that of powder with increasing of the film thickness.SEM showed that the as-prepared films is not ideal,but does not affect luminescence.The photoluminescence spectrum showed that the films had no red excitation spectrum after annealing at 650℃.
DING Shi-wen, ZHANG Xing-wei, WANG Li-yong, ZHANG Yong-fen. Preparation of Nano-TiO2/Diatomite Compositeby Emulsion Dipping[J]. Journal of Materials Engineering, 2008, 0(10): 50-52,59.
A mixed crystal nano TiO2 was prepared by two-step hydrolyzing method at atmosphere,and using the simple and easy obtained OP as a well dispersed emulsion.Dipping it into the diatomite,the TiO2/diatomite composite was made.SEM,XRD,EDS and the experiment of adsorption and photo-catalysis for scarlet 3R were used to characterize the samples.The result showed that it was a composite with mixed crystal TiO2 with anatase and rutile which diameter is 12nm and diatomite which has a lot of holes.The 23% ratio of TiO2 to diatomite and pH=3 was best for photo catalysis experiment proves that the reaction was happened on the surface of catalyzer but not in the water.
ZHANG Xue-jun, FU Li-ye, ZHANG Meng-meng, LIU Peng, GUO Zhi-hui. Solution Method for Synthesizing Nanocrystal of Metal Oxide[J]. Journal of Materials Engineering, 2008, 0(10): 53-59.
The solution method,such as the sol-gel process,could directly synthesize nano-scale metal oxide crystal and dope nano-scale metal oxide crystal under assistance of anion-exchange resin and organic solvent.The synthesized nano-scale crystals were dried through the azeotropic distillation using iso-amyl acetate as azeotropic solvent and a highly dispersed powder was obtained.The analysis that conducted on transmission electron microscope(TEM) and X-ray diffractometer(XRD) demonstrated the nano-scale powder did possess distinctly crystalline structure,and showed a high photo-catalysis and anti-bacterial that only crystal had.
DENG Hua, REN Wei, HUANG Zhan-lin, XIAO Chang-fa. Synthesis of Nanoscale Iodine Doped TiO2 and Properties Treated Cotton Fabric[J]. Journal of Materials Engineering, 2008, 0(10): 60-63,67.
Iodine doped nanoscale TiO2 was prepared by sol-gel method at the temperature lower than 100℃.Also,the resultant I-TiO2 was prepared an aqueous solution that used to treat the fabrics.The crystal structure,particle size and the properties of I-TiO2 were characterized by XRD and UV-vis absorption spectra etc.The results show that the produced I-TiO2 is a nanocrystalline with anatase-phase only and the size of particles is about 6nm.The width of absorption zone of the solution contained I-TiO2 is increased.Besides,the fabrics treated with nano I-TiO2 solution have an excellent performance on both ultraviolet protection and antibacterial.
GAN Xiao-yan, LI Xiao-min, GAO Xiang-dong, YU Wei-dong, ZHUGE Fu-wei,. Electrochemical Deposition of Nanoporous ZnO Films and Their Photoelectrochemical Performance[J]. Journal of Materials Engineering, 2008, 0(10): 64-67.
Nanoporous ZnO films were fabricated on ITO substrate by a two-step solution approach,which involves the electrochemical deposition of nanoporous ZnO/eosin Y hybrid films and subsequently desorption treatment to remove eosin Y molecules.Nanoporous ZnO films with grain size of 10-20nm were obtained.The X-ray diffraction pattern showed that nanoporous ZnO film had a hexagonal wurtzite structure,and the EDS results exhibited that the film was composed of Zn and O,and no other elements was detected.The prototype dye sensitized solar cell device utilizing the nanoporous film as photoelectrode was fabricated,exhibiting an open-circuit photovoltage of 0.68V,a short-circuit photocurrent density of 0.79mA/cm2,and an overall conversation efficiency of 0.26% under white light illumination.
LIU Chang-jiu, WU Hua-bin, LI Yan-wei, CHEN Shi-juan. Investigations on Electrochemical Performance of La(III) and Sr(II) Codoped Amorphous Nickel Hydroxide[J]. Journal of Materials Engineering, 2008, 0(10): 68-71,75.
Amorphous nickel hydroxide codoped with La(III) and Sr(II) has been synthesized by microemulsion method.The microstructure and morphology of the sample were characterized by XRD,Raman,and SEM.To investigate the effect of La(III) and Sr(II) codoping on the electrochemical performance of the samples,simulated batteries with the prepared codoping nickel hydroxide as cathode active material and metal hydride as counter electrode were assembled.At the 0.1C rate,the discharge platform was 1.265V and the specific discharge capacity was 340.56mAhg-1 for the La(III) and Sr(II) codoped sample.In addition,the stability and reversibility of the La(III) and Sr(II) codoped sample was relatively good and the oxygen evolution was impeded during the charge/discharge process.
XI Li, QIAO Wen, LI Ming-jie, GE Shi-hui. Critical Behavior Near Ferromagnetic-paramagnetic Phase Transition in Nano-polycrystalline La0.7Sr0.3MnO3[J]. Journal of Materials Engineering, 2008, 0(10): 72-75.
Nano-polycrystalline La0.7Sr0.3MnO3 samples were fabricated by Sol-Gel method at different sintered temperatures.Field and temperature-dependent AC susceptibility has been measured in these samples.The critical peak values near their ferromagnetic-paramagnetic phase transition temperatures reveal that the curie temperature TC= 312.1K±0.2K and the critical exponents δ=3.040,γ=1.007,β=0.493 for the 973K sintered sample;TC=331.7K±0.1K,δ=2.950,γ=0.993 and β=0.508 for the 1173K sintered sample,respectively.These results consist with the mean-field theory,indicating that a long-range interaction in these materials.
QIN Dong-huan, LIU Hong-mei, TAO Hong, LAN Lin-feng, CHEN Jun-wu, CAO Yong. Controlled Synthesis of VI Group Element Semiconductor Nanowires and Their Nano-electronic Properties[J]. Journal of Materials Engineering, 2008, 0(10): 76-79,84.
Homogeneous,highly crystalline Se and Te nanowires(NWs) were prepared by a chemical solution process using selenious acid and orthotelluric acid as precursor materials.HRTEM images show that the Se or Te NW are single crystalline with their growth direction along the [001],with the helical chains of Se or Te atoms parallel to the longitudinal axis.Se and Te NWs field effective transistor device were prepared by photolithography or e-beam lithography.The device performance show that Se or Te is p type semiconductor with hole mobility about 30.7,70cm2V-1s-1 respectively.This result is very important to the application of nanoscale electronic device.
TANG Ai-min, WANG Xin, CHEN Gang, ZHANG Hong-wei. Study on Characteristics of In-situ Composition of Nature Kapok Fibers/Magnetic Nano-particles[J]. Journal of Materials Engineering, 2008, 0(10): 80-84.
Kapok fiber/magnetic nanocomposites were prepared by in-situ composition using nature kapok fibers as matrix.The influences of pretreatment and maturing methods on composition efficiency were studied.The structure and magnetic properties were characterized by SEM,AFM,X-ray diffraction and superconducting quantum interference device(SQUID).Results showed that kapok fibers were suitable templates for the composition and magnetic particles were composited both on fibers' surface and the inner surface of the lumen.The iron oxide synthesized was mainly in the C phase of γ-Fe2O3 and its size was between 30-100nm.The kapok fibers/magnetic nano-composite prepared by maturing under a static magnetic field yields the highest mass fraction of Fe as 7.54%.SQUID showed that the kapok fiber/magnetic nano-composite was superparamagnetic.
LI Yong-li, CAI Bo-qi, ZHANG Jiu-xing. Preparation of BN Nanotube by Magnesiothermic Reduction[J]. Journal of Materials Engineering, 2008, 0(10): 85-87.
A multi-walled boron nitride nanotubes were prepared by the magnesiothermic reaction at 1500-1600℃ under the ammonia gas flow,which employed B2O3 and Mg powders as raw materials and reductant respectively.The as synthesized BN nanotubes show a uniform diameter of around 50nm and a length of 10-30μm.The smooth surface and open-ends of BN nanotubes were observed by SEM and HRTEM microscopy.XRD,EDS and SAED confirmed that the compositions of the nanotubes were mainly hexagonal BN.
ZHANG Hong-wei, SHI Jian-ping, SUN Dan-dan. Effect of Nano-sized Halloysite on Properties of Coating and Coated Paper[J]. Journal of Materials Engineering, 2008, 0(10): 88-91.
The effect of the amount of nano-sized halloysite on the properties of coating and coated paper was studied,with halloysite,GCC,Clay as pigments.The results showed that,the nano-sized halloysite has special particle morphology and size,and it has significant influence on coating and coated paper.The viscosity of coating increased with the increase of the amount of halloysite,and the water retention value becomes a little smaller.The brightness,gloss,surface printing strength increased with the increase of the amount of halloysite,and the smooth,ink absorption also have certain improvement.
HAN Jian-qiang, LU Shao-yong, LI Qing, WANG Jiang-ying. Microfabrication Silicon Tips in Iodine-supersaturated KOH Solution[J]. Journal of Materials Engineering, 2008, 0(10): 92-94,97.
Etching silicon tips in anisotropic KOH solution is simple,easy to handle,low cost and homogeneous etching rate of(100) crystal plane on a whole wafer.Unfortunately the homogeneity of undercutting silicon tips is bad,and the etching ratio of(100) crystal plane to that of undercutting rate is small.In addition,the figure of silicon tips etched in KOH solution is unsymmetrical eight sided pyramid.In this paper,the undercutting rate of silicon tips are improved by adding supersaturated iodine and KI in KOH solution.The figure of silicon tips etched in this novel etching solution is rocket tips on right rectangular pyramid rather than unsymmetrical eight sided pyramid etched in other etching solution.As a result,good characteristic of scanning and tunneling can be achieved by using silicon tips etched in the iodine-supersaturated KOH solution.
DENG Mei-gen. Investigation of Anion Reducing Agents Prepared Nanosized MnO2 for Supercapacitors[J]. Journal of Materials Engineering, 2008, 0(10): 95-97.
MnO2 was prepared by using KMnO4 as the oxidant and NaHSO3 as the reducing agent.The samples were analyzed by N2 adsorption,scanning electron microscopy(SEM) and X-ray diffraction(XRD).Cyclic voltammetry and galvanostatic charge/discharge were used to characterize the electrochemical performance of the samples.The results showed the as prepared MnO2 is amorphous with a diameter of 20 to 40nm and a BET specific surface area of 155.4m2g-1.In an electrolyte of 1mol L-1(NH4)2SO4,the nanosized MnO2 had typical capacitive characterization in the potential region of-0.4-0.5V(vs.SCE).At a current density of 10mA·cm-2,the MnO2 had a specific capacitance of 325F·g-1.
WANG Xing-yao, HAN Jun-yuan, WANG Jing, YANG Gui-qin. Synthesis of Spinel MgFe2O4 Nano-powder by Hydrothermal Stripping[J]. Journal of Materials Engineering, 2008, 0(10): 98-100,105.
A new method of synthesis of spinel MgFe2O4 nano-powder,the hydrothermal stripping,was introduced,and it was applied to synthesize MgFe2O4 nano-powders of 12-18nm.Some factors influencing morphology and size of MgFe2O4 powders,such as stripping temperature,the pH and ingredients of water phase,were investigated with the help of XRD and TEM.The results suggest that the MgFe2O4 nano-powders can be synthesized with water directly from the mix inorganic phase of iron-loaded and magnesium loaded at 210-220℃.This method can give a typical spinelferrite with well crystallized,much narrower particle size distribution shaped in quasi-sphere and without agglomeration.
WANG Yao, WANG Ling-yuan, TANG Jian-guo, YANG Bo. Preparation and Properties of PET-PEG-SiO2 Co-polymerized Hybrid Nanoblocks[J]. Journal of Materials Engineering, 2008, 0(10): 101-105.
Poly(ethylene glycol)(PEG) was grafted onto the surface of pre-activated nanoSiO2 to obtain PEG-SiO2 composites.At the same time,low molecular weight poly(ethylene terephthalate)(LMPET) was obtained through esterification exchange of dimethyl terephthalate(DMT) and ethylene glycol(EG).The LMPET-PEG-SiO2 hybrid nanoblocks were prepared through the copolymerization of PEG-SiO2 and LMPET.Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS) and nuclear magnetic resonance(1H-NMR) results proved that LMPET was successfully linked onto SiO2 surface through PEG.The DSC data exhibited that the small changed of the thermal properties of LMPET occurred after hybrid copolymerization,i.e.4℃ decreased of Tmc and 3℃ decreased of Tm.
XIE Xiao-bao, LI Wen-ru, ZENG Hai-yan, OUYANG You-sheng, CHEN Yi-ben,. Study of Antimicrobial Activity and Mechanism of Silver Nanoparticles on Escherichia coli[J]. Journal of Materials Engineering, 2008, 0(10): 106-109.
The antimicrobial effect of the nanosilver on Escherichia coli and the antimicrobial mechanism was studied elementarily.Experimental results indicated that the silver nanoparticles of 20μg/mL could inhibit completely the growth of 106cfu/mL cells in liquid LB medium.The growth curves showed that silver nanoparticles prolonged the lag phase of E.coli,and the higher of the concentration of silver nanoparticles,the longer of the lag phase of E.coli.Transmission electron microscopy(TEM) was used to evaluate the cell morphology of both the normal and the treated E.coli.The observation with TEM suggested that silver nanoparticles lead to the formation of "pits" in cell wall of the bacteria,and silver nanoparticles could enter into periplasm through the pits and destroyed the cell membrane.Then the silver nanoparticles could enter into the bacterial cell,which not only condensed DNA,but also combined and coagulated with the cytoplasm of damaged bacteria.Finally,silver nanoparticles resulted in the leakage of cytoplasmic component.Moreover,the analysis of agar gel electrophoresis demonstrated that silver nanoparticles could increase the decomposability of genome DNA.
YUAN Hao, XIE Li-li, TIAN Zhen, WANG Li-jun. Application of Ultraviolet Treatment on Synthesis of Pure-silica Zeolite Low Dielectric Constant Thin Films[J]. Journal of Materials Engineering, 2008, 0(10): 110-113.
A novel photochemical approach was developed in the preparation of pure-silica zeolite thin films having low dielectric constants(ε).Transparent pure-silica zeolite films were synthesized on silicon wafers through hydrothermal reaction,in which tetraethylsilanoxide(TEOS) was used as silica source,tetrapropyl ammoniumoxide(TPAOH) as template and alkaline source.An ultraviolet treatment was subsequently applied to remove the organic templates within the pores/channels of zeolite films.The thin films were characterized by using FT-IR,XRD and SEM techniques before and after the ultraviolet treatment.FTIR results showed that the organic templates were effectively removed via ultraviolet treatment,which was the same as the results from the calcinations treatment.In comparison with the calcined films,XRD and SEM results indicated that the crystallinity and the surface as well as the thickness of the films had no significant changes after ultraviolet treatment.ε values of the thin films were measured by means of impedance analyzer.Elastic modulus and hardness of the thin films were measured by the nano-indentation technique.All results shown that the films after ultraviolet treatment had a lower ε value and higher mechanical strength.
MA Rui-ting, ZHAO Hai-tao, ZHAO Hui, ZHANG Gang, SONG Kai. Influences of Ce3+ Substitution on Electromagnetic Properties of Nanocrystalline Ni0.5Zn0.5Fe2O4 Ferrites[J]. Journal of Materials Engineering, 2008, 0(10): 114-117.
Nanocrystalline Ni0.5Zn0.5CexFe2-xO4(x=0,0.05) powders were prepared using polyacrylamide gel method with acrylamide as monomer and N,N′-methylenediacrylamide as lattice agent.The analysis methods of X-ray,FI-IR,TEM and wave-guide were used to characterize the products.The X-ray study showed that the pure spinel Ni0.5Zn0.5CexFe2-xO4(x=0,0.05) formed at 600℃.The average diameter of the Ni0.5Zn0.5Fe2O4 crystalline particles was about 30nm identified by TEM.The nanocrystalline Ni0.5Zn0.5CexFe2-xO4(x=0,0.05) had both dielectric loss(ε″) and magnetic loss(μ″),while the ε″ and μ″ of Ni0.5Zn0.5Ce0.05Fe1.95O4 were higher than that of Ni0.5Zn0.5Fe2O4.The maximum of ε″ and μ″ of the Ni0.5Zn0.5Ce0.05Fe1.95O4 was around 0.93 and 0.15,respectively.
Wide Photonic Band Gaps(PBG) with low refractive index materials were fabricated using two-photon nanofabrication technique.The fittest lattice change condition was deduced by a simple method.The PBG of the gradient quasi-diamond lattices was experimentally confirmed by reflection and transmission measurements and simulation of Finite Difference Time Domain(FDTD) calculations.The results indicate that a three dimensional photonic crystals with gradient lattices could effectively expand the width of the PBG.
HA En-hua, HUANG Da-qing, HA En-ping, WANG Zhi-yong, DING He-yan. Preparation and Characterization of Carbon Nanotube/Conducting Polymer Nanocomposites[J]. Journal of Materials Engineering, 2008, 0(10): 122-125.
To manufacture transparent conductive coating with excellent transparence and conductivity,it was necessary to introduce self-assemble carbon nanotubes into an integrated conductive network effectively in resin media.The combination of carbon nanotubes with polymers offers an attractive route to introduce new electronic properties based on morphological modification or electronic interaction between the two components.carbon nanotube/poly(3,4-ethylenedioxythiophene)(PEDOT) nanocomposites and carbon nanotube/polyanicine nanocomposites were prepared by in situ potentiostatic deposition of PEDOT or PANi onto carbon nanotubes and characterized with TEM,FTIR and standard four-probe method.The synthesis of the nanocomposites with microscopic structure not only forges a solid basis for both the self-assembling of all kinds of nanocomposites for versatile application.
SONG Xiao-lan, ZHANG Xiao-wei, XU Da-yu, YU Zhen-xing, QIU Guan-zhou. Electrochemical Study on Corrosion Behaviors of p-silicon Wafers in KOH Solutions[J]. Journal of Materials Engineering, 2008, 0(10): 126-131.
The corrosion behaviors of p-type(100) and p-type(111) silicon wafers etched in KOH solutions were investigated by using electrochemical DC polarization techniques and the influences of the KOH solution temperature,concentration and surface crevices on the corrosion behaviors of silicon wafers were studied.The results reveal that corrosion rate reach the maximum when the KOH concentration is 5-6mol/L at room temperature for p-type(100) and p-type(111) silicon.With solution temperature increasing,the corrosion rate increases,and at 50℃ the corrosion rate increases significantly.Crevice exacerbates the corrosion rate of local silicon.The corrosion rate will be an order of magnitude faster than the uniform corrosion under the same conditions.
YAO Wen-zhao, LIU Yu-hua, LIU Yu-feng. Study on Relations Between Preparation Technology and Turbidity of Nanoscale Calcium Sulphonate[J]. Journal of Materials Engineering, 2008, 0(10): 132-136,141.
The relations between turbidity and micellar structure of overbased calcium sulphonate were studied.The influence factors of turbidity,such as different co-promoters,overbased process,post-process condition in the preparation of calcium sulphonate were studied,and the forming reason of loading-carrying micelle was explained,so the product can have better quality and performance.
ZHENG Zhi-jun, GAO Yan. Quantitative Measurement of Deformation-induced Martensite During ECAP of 304 Stainless Steel[J]. Journal of Materials Engineering, 2008, 0(10): 137-141.
X-ray diffraction method is used for identifying and evaluating deformation-induced transformation in 304 austenitic stainless steel after extrusion by ECAP and annealing.The results indicated that both α′and ε-martensites were clearly present in 304 stainless steel extruded by ECAP,where the volume percentage of α′-martensite is higher than that of ε-martensite,and the volume percentage of α′-martensite evidently decreased and that of ε-martensite relatively increased after annealing treatment of the extruded stainless steel.The results also revealed that there was a remarkable decrease of the volume percentage of austenite phase after the first-pass pressing,however,it was less influenced by pressing and annealing thereafter.
DING Shi-wen, CHENG Yun, WANG Jing. Electical Property and Preparation of PTC Ceramics Synthesized by Liquid Mixes[J]. Journal of Materials Engineering, 2008, 0(10): 142-144.
A series of nano-Ba0.93-xYxSr0.07MnyTi1-yO3 solid solutions were synthesized by solid-state reaction at low temperature.XRD pattern demonstrated that the compounds were mutually miscible in the solid solutions.The TEM photograph showed that the compounds had a shape of uniform,substantially spherical particles with an average partical size of 70nm in diameter.The PTC effect of the materials were studied by preparing ceramics.It was found that the resistance is near 37.09Ω at room temprature,ratio of lg(Rmax/Rmin)is 2.957×105 and temperature coefficient of resistance α is 23.36%/℃ when the content of Y and Mn are 1% and 0.04%(mole fraction) respectively.
PAN Chao, DONG Li, WANG Jing, GU Zhong-ze. Fabrication of TiO2 Hybrid Hollow Nanofibrous Photocatalyst by Electrostatic Layer by Layer Technique[J]. Journal of Materials Engineering, 2008, 0(10): 145-149,153.
Hybrid multilayered hollow nanofibers composed by TiO2/ polyelectrolyte(PE) have been prepared by a combination of electrospinning method and Layer-By-Layer(LBL) technology.Polystyrene(PS) was electrospun into nanofibrous mats,which was employed as templates to self-assembly multilayered polyelectrolytes(PE) on the surface.Hybrid multilayered hollow nanofibers were obtained after the template PS were selectively removed.The results show that the average diameter of the hollow nanofibers and the wall thickness can be well controlled by the template as well as the numbers of the coating layers.When comparing with other nanostructured TiO2 materials such as commercial TiO2 nanoparticles(P25,Degussa) and TiO2 films,the hollow TiO2/PE hybrid nanofibers exhibited higher photocatalytic activities.Such hollow nanofibers have potential applications in a wide field,for example,catalysts,controlled release medicine and so on.
TAO Fei-fei, XU Zheng. Electrochemical Fabrication of Dendrite-like Copper Crystals[J]. Journal of Materials Engineering, 2008, 0(10): 150-153.
Using copper chloride as the precursor and sodium dodecyl sulfate(SDS) as the additive,the dendrite-like copper crystals were successfully fabricated by electrochemical deposition at the room temperature.The morphology and structure of the dendrite-like copper crystals with micrometer size and face-centered cubic structure were characterized by using scanning electron microscopy(SEM) and X-ray diffraction(XRD).Through the investigation for the effect of the experimental parameters,such as the electrodeposition time,the voltage and the concentration of sodium dodecyl sulfate(SDS),on the shapes of dendrite-like copper crystals,the formation process was studied and it went through the nucleation,growth and revegetation process.
CHEN Hao, ZHAO Jie. The Difference of Selective Adsorption Between Palygorskite and Acid-activated Palygorskite for Pb(Ⅱ) and Zn(Ⅱ)[J]. Journal of Materials Engineering, 2008, 0(10): 154-157.
A batch experiment was conducted to study the adsorption of Pb(Ⅱ) and Zn(Ⅱ) by natural and acid-activated palygorskites in single component and binary systems.The results showed that selective adsorption of natural and acid-activated palygorskites are both prior to Pb2+ than Zn2+,but a higher selective adsorption for Zn2+ was obtained by acid-activated palygorskite compared with that of palygorskite.Selective adsorption of palygorskite for Pb2+ and Zn2+ become stronger and weaker with the increase of temperature,respectively.For acid-activated palygorskite,the selective adsorption for Pb2+ and Zn2+ become strongest and weakest in 40℃,respectively.The dissimilarity in dominant adsorption mechanisms was a main reason resulted in the difference of selective adsorption of the two adsorbents.
LI Hai-tao, LIU Li-hu, FAN Sheng-hua, SUN Hui-yuan,. Structure and Magnetic Properties of the Nickel Nanowire Compounded with Zinc[J]. Journal of Materials Engineering, 2008, 0(10): 158-160.
Ni nanowire arrays compounded with Zn were fabricated by electrodeposition using porous anodic aluminum oxide membrane as templates in acidic coating bath at room temperature.The images of Ni nanowires are studied by scanning electron microscope(SEM),transmission electron microscope(TEM) and atom force microscope(AFM),respectively.X-ray diffraction(XRD) and vibrating sample magnetometer(VSM) are employed to study the structural and magnetic properties of the nanowires.The results indicate that the nanowire arrays have a preferred orientation along [111] direction and the easy axis is parallel to the long axis of nanowire.
LIU Xiao-dan, GUO Min, ZHANG Mei, WANG Xi-dong, ZHOU Guo-Zhi. Synthesis and Characterization of Cu-Ni Composite Nanoparticles in Ethylene Glycol[J]. Journal of Materials Engineering, 2008, 0(10): 161-164.
Cu-Ni composite nanoparticles were successfully prepared by chemical reduction with hydrazine hydrate in ethylene glycol.XRD,TEM,EDS were employed to characterize the Cu-Ni composite powders.Effects of molar ratio of Cu2+ to Ni2+ on the composition of the product and the mass concentration of PVP on the size of the Cu-Ni composite particles were studied.The molar ratio Cu to Ni of the product increased with the increasing of that of Cu2+ to Ni2+ of the reactant,and the size of the Cu-Ni composite nanoparticles decreased with the increasing of the PVP.Experiment results indicated that the composition and the size of the Cu-Ni nanoparticles could be easily controlled by changing the molar ratio of Cu2+ to Ni2+ and the mass concentration of PVP.
DING Xi-dong, GUAN Jing-xin, HUANG Long-fei, WU Jun-han. The Development and Commercialization of Nanoscale Impedance Microscopy[J]. Journal of Materials Engineering, 2008, 0(10): 165-168,172.
Nanoscale impedance microscopy(NIM),which can measure the local impedance of material surface,is an important instrument for material characterization on nanoscale.The application of NIM has been greatly extended recently overseas though still limited on laboratories though no reference about it was found domestically.In this paper,the principle of NIM is introduced and its realization is presented.Base on commercial scanning probe microscopies(SPM),two various NIM were developed and the commercialization of NIM came true for the first time with a home-made SPM.The application of this technique was demonstrated with ceramic materials such as polycrystalline ZnO.
YANG Qin-yu, LIU Lei, DING Ke, ZHANG Jing, WANG Qing-rui. Effect of Duty Cycle on Porous Silica Film Raman Spectra[J]. Journal of Materials Engineering, 2008, 0(10): 169-172.
Porous silica films were prepared by plasma enhanced chemical vapor deposition(PECVD) system modulated by pulse negative bias voltage and silane as precursor gas.During duty cycle from 0.162 to 0.864 maintaining bias voltage at -300V,the Raman spectra and microstructure of the samples were investigated intensively.It was found that Raman peak appeared at 480cm-1 and 560cm-1 while the intensity of 480cm-1 peak weakened and that of 560cm-1 strengthened and blue shift with the increase of duty cycle.Raman spectra indicated that amorphous silicon vanished when duty cycle was at 0.702.The proportion of Si—O—Si bridge bond enhanced while the duty cycle increasing.The SEM revealed that the size of silica particles became smaller and silica films got more porous and fleecy.
LIU Xiao-qi, DUAN Xue-chen, YAN Rui-feng, LI Hai-bin, CHEN Jie-nan, HE Gang. Preparation and Characterization of Nano-attapulgite Clay Mine[J]. Journal of Materials Engineering, 2008, 0(10): 173-176,182.
Nano-attapulgite clay mine were prepared by ultrasound hydrothermal method,adding quantitative dispersing agent,at a certain pH value,time and temperature conditions,the method can prepare 50-200nm nanoparticles attapulgite.Nano-attapulgite clay mine was characterized and observed by scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and other means of testing.The morphology,formation mechanism and its crystal structure of nano-attapulgite clay mine can be discussed.The results showed that the size and shape of nano-attapulgite were also different in different conditions.In different reactions acid system,the structure of nano-attapulgite clay mine that prepared by ultrasound hydrothermal method had changed.
YANG Jing, CHEN Jie-rong. Surface Free Energy and Surface Structure of Methyl-modified Silica Membranes[J]. Journal of Materials Engineering, 2008, 0(10): 177-182.
Silica membranes modified with methyltriethoxysilane(MTES) have been prepared by acid-catalyzed co-hydrolysis and condensation reactions of tetraethylorthosilicate(TEOS) and MTES.The surface wettability,surface structure and water absorbed amount of the silica membranes were investigated.The contact angles of the samples were measured.The values of dispersion force γSd,dipole force γSP and hygrogen bonding force γSh to the surface tensions for the silica membranes were evaluated by the extended Fowkes equation.Mainly because of the contribution of hygrogen bonding force,the surface free energy and surface wettability of the silica membranes decrease greatly with increasing MTES/TEOS ratio.X-ray photoelectron spectroscopy(XPS) shows that the reason was the increase of Si—CH3 functional group and the decrease of Si—O and O—H functional groups on the surface of silica membranes.The physisorbed water amount decreases with the MTES/TEOS ratio increased.The MTES/TEOS ratio for hydrophobic silica membrane should be above 0.8.
WANG Heng, HU Lian-xi, CHEN Xian-jue. Microstructure Evolution of AZ31 Magnesium Alloy Powders Prepared by Mechanical Milling in Hydrogen Atmosphere[J]. Journal of Materials Engineering, 2008, 0(10): 183-186.
AZ31 magnesium alloy powders were prepared by mechanical milling in a hydrogen atmosphere.Nanocrystalline MgH2 was created by the reaction of magnesium alloy powders and hydrogen attributed to the mechanical force.The microstructure evolution of the alloy during mechanical milling was characterized by means of X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM),respectively.The results showed that,during milling,the powders were at first rolled into flakes,and then,with the further increased of the milling time,the powders refined gradually.After milling for 80h,the nanocrystalline MgH2 powders,with grain size of about 10nm and particle size of 1-3μm in average respectively,were obtained.
ZHANG Da-bin, ZHOU Yuan-kang, YANG L, WANG Man-li. Effect of Mass Fraction of Palygorskite Nano-particles on Phenolic Resin and Tribological Behavior of Friction Materials by in-situ Method[J]. Journal of Materials Engineering, 2008, 0(10): 187-190.
0.3%,0.7%,1.0% and 1.3% of the palygorskite nano-particles(P nano-particles) were separately added in prepolymer.Palygorskite/tung oil phenolic resin was synthesized with in-situ method(it is called P/TPF).The disperse state of nano-particles in phenolic resin was observed by TEM,the synthetic resin was carried out TG analysis by SETARAM TG-DSC92-16 thermal analyzer,and the synthetic resin was woven into the production of friction materials and the production was tested on its tribological behavior by DMS-1.The results show that thermal weight loss rate of the resin in the range 0.3%-1.0% of P nano-paricles is linear descending from 240℃ to 600℃.When the mass number of P nano-particles is 1.0% in the resin,the integrative behavior of friction material is most optimized.Temperature of the heat resistance can be up to 280℃.Abrasion resistance of the friction materials is also best and its wear rate is an increase of 15% compared with tung oil phenolic resin without P nano-particles.
FANG Ruo-yu, HUANG Jian-guo. Artificial Fossilization Process: A Shortcut to Nanostructured Materials with Complex Morphologies[J]. Journal of Materials Engineering, 2008, 0(10): 191-196.
Fabrication of nanostructured materials by using natural substances as templates or scaffolds is a frontier research field in nanoscience and technology.We recently developed an "artificial fossilization process" to prepare novel functional nanomaterials by precise replication of natural substances with various guest matrices.This review describes the application of this process in the syntheses of different functional nanomaterials such as metal oxides and nanotube/nanoparticle hybrids.
DING Hao-ran, WANG Shu-lin. Study on Photocatalytic Performance of Hydrolyzated Zinc Oxide Nano-structures[J]. Journal of Materials Engineering, 2008, 0(10): 197-199,203.
The roller vibration milling was used to manufacture Zinc nanoparticles with wurtzite hexagonal phase in dry mode and at room temperature,then hydrolyzed zinc nanoparticles with water vapour at 260℃ to obtain ZnO nanostructure or hybrid of ZnO and Zn nanostructures.Results show that the nano-structures synthesized at 260℃ have great dispersivity featuring nano-flakes with nano-rods,that containing about 60% Zn atoms and 40% Oatoms.Using the produced hybrid nanostructures as catalyst,exposed the 20mg/L methyl orange solution to a UV source light of 20W with distance of 40cm,then problems about how the original centigrade,catalyst addition and hydrogen temperature influenced the photocatalytic performance of the hybrid nanostructures were studied.Once added 400mg catalyst into 50mL 10mg/L methyl orange solution,exposed to a 20W UV source for 10min,the decomposition degree rised above 80%.The findings were proved to provide a new way to enhance the decomposition of dye wastewater by nanostructures.
LU Nian-duan, SONG Xiao-yan, ZHANG Jiu-xing. Preparation and Characterization of Sm2Co17 Nanocrystalline Bulk[J]. Journal of Materials Engineering, 2008, 0(10): 200-203.
The nanocrystalline Sm2Co17 bulk was prepared by a new developed method.The phase stability and microstructure were analyzed by XRD and TEM methods.It was found that the nanocrystalline Sm2Co17 bulk has a hexagonal phase with Th2Ni17 crystal structure at the room temperature,which only exists at the high temperature in the polycrystalline Sm2Co17 bulk.The hysteresis loops and the mechanical properties were measured for the prepared material.The magnetic and the mechanical properties of the nanocrystalline Sm2Co17 bulk with the hexagonal structure were greatly increased as compared with the polycrystalline alloy with the rhombohedral structure.
ZHAI Hua-zhang, DAI Jin-hui, LI Jian-bao, CAO Chuan-bao, CAI Hong-nian. Preparation and Magnetic Properties of Nano-nickel Coated Silicon Nitride Composite Powders[J]. Journal of Materials Engineering, 2008, 0(10): 204-207.
Nano-nickel coated silicon nitride composite powders are prepared by simple electroless plating.The uniform nickel coatings are obtained by adjusting the different PH values and stirrer modes.The phase composition and morphology of composite powders are characterized by X-ray diffusion(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).Magnetic properties measurement proved that coated composite powders have fine ferromagnetism and magnetic anisotropy.
ZHANG Yi-bang, CHEN Yan-yan, JIN Gang. Application of PEGylated Phospholipid Membrane in Surface Modification of Protein Chips[J]. Journal of Materials Engineering, 2008, 0(10): 208-210.
Application of PEGylated phospholipid membrane in surface modification of oxidized silicon is studied here.Silicon dioxide surfaces are covered by phospholipid membrane with variable molar fractions of DSPE-PEG2000-COOH,and obvious resistance to non-specific protein adsorption on PEGylated phospholipid membrane is obtained.Also,ligand and its corresponding antibody can be effectively assembled on functionalized PEGylated phospholipid membrane.
ZHAO Si-qin, GUO Min, ZHANG Mei, WANG Xi-dong. Study on Preparation of Eu3+ Doped Titania Nano Crystals and Photoluminescence Property[J]. Journal of Materials Engineering, 2008, 0(10): 211-214,218.
Titania and Eu3+ doped titania nanocrystals were prepared by sol-gel method.The samples were characterized by XRD and photoluminescence(PL) spectra.The XRD results showed that particle size of titania remarkably became smaller and the phase changed temperature of crystals was increased with the Eu3+ doping.As a result,the phase changed temperature of crystals was increased.And the PL spectra resulted revealed that the properties of Eu3+ doped in titania system were obviously improved.With the content of Eu3+ increasing,PL property was greatly improved.Furthermore,the PL property of nanocrystals synthesized by Eu2(camphoracid)3(1,10-phenanthroline)2 precursor was much better than that prepared by Eu(NO3)3·6H2O precursor.
LIU Xin-yu, JIANG Min-hong, ZHOU Xiu-juan, CHEN Jun, WANG Zhong-min. RF Magnetron Sputtering Process and Photoelectric Property of Al Doped ZnO Films[J]. Journal of Materials Engineering, 2008, 0(10): 215-218.
Al-doped ZnO(ZAO) films were prepared on glass substrates at room temperature by RF magnetron sputtering.The microstructures of ZAO films were investigated with X-ray diffraction(XRD) and its optical and electrical properties were respectively measured using a four-point probe technique and UV-756 spectrophotometer at the room temperature.With increasing the sputtering time,the structure of ZAO films changes from non crystalline structure to crystalline structure,and at the same time the intensity of(002) peak changes,and the optical band gap of ZAO films reduces.But the optical band gap of the ZAO films increases after vacuum annealed at 400℃ for 2h.The increasing of sputtering time and the annealing treatment make the transmittance of ZAO films reduce,but the transmittance of ZAO films is all higher than 90%.With increasing of sputtering time,the resistivity of films first reduces,and then increases slightly.The annealing treatment make the resistivity of ZAO films reduces evidently,and the ZAO film sample annealed for 2h of sputtering time gains the lowest resistivity,9.4×10-4Ω·cm,and the lowest square resistance,18.80Ω/□.
WANG Xue-hua, LI Cheng-yong, MA Lian-jiao, LIU Jun, CAO Hong. Structural Parameters and Distribution Rules of Highly Ordered AAO Pores[J]. Journal of Materials Engineering, 2008, 0(10): 219-222,227.
Anodic aluminum oxide(AAO) with highly ordered pores was prepared by secondary anodic oxidation.The effects of anodic voltage and oxalic acid concentration on diameter of AAO were investigated respectively.The results showed that the pore size was increased from 76nm to 95nm with the oxidation voltage increasing from 35V to 45V when the oxalic acid concentration was 0.5 mol·L-1,and the pore size was increased from 75nm to 95nm with the oxalic acid concentration increasing from 0.3 mol·L-1 to 0.5 mol·L-1 when the oxidation voltage was 45V.Pore size distribution was accord with normal distribution.SEM images showed that the pores of AAO prepared under above conditions were highly ordered.The pore size and distribution of AAO can be controlled well by adjusting oxidation voltage and oxalic acid concentration moderately.
JIN Ding-feng, WANG Xin-qing, JIN Hong-xiao, HOU Zhao-Yin, ZHENG Xiao-ming, GE Hong-liang. Synthesis and Performance of Sulfated Mesoporous Zorcina Solid Superacid[J]. Journal of Materials Engineering, 2008, 0(10): 223-227.
As the activity of different acids for the condensation between toluene and formaldehyde depended on the proporation of its strong acid site,mesoporous zirconia supported sulfate acid was synthesized via the self-assembly method and characterized via XRD,N2-adsorption and HRTEM.The thermal stability of the prepared mesoporous zirconia supported sulfate acids were checked at different calcination temperature.It was found that the structure of mesoporous zirconia remained under 600℃,but damaged at higher temperature.NH3-TPD found that the catalyst calcined at 500℃ has the highest acid amount and this catalyst showed the highest activity in the condensation between toluene and formaldehyde.The conversion of formaldehyde reached 45.7%.
SHAO Yan-qun, TANG Dian. Study on Microstructure of 20% RuO2-80% SnO2 Prepared by Citrate-gel Method Using SnCl2 and SnCl4 as Precursor[J]. Journal of Materials Engineering, 2008, 0(10): 228-231,235.
Nano-sized 20%RuO2-80%SnO2 materials were synthesized by the citrate-gel method using RuCl3,SnCl2,SnCl4 and citric acid as precursor and anhydrous ethanol as solvent.The structures of the derived powders were characterized by XRD,TEM and BET techniques.It is shown that the materials obtained were composed of rutile-type oxide phases with fairly narrow distribution in size and good thermal resistant properties.(Ru,Sn)O2 with sizes of about 10nm was obtained when SnCl2 was used as source material.Rutile-type mixed oxides of SnO2 and RuO2 was obtained while SnCl4 was used as source material.Sn ions can effectively increase the temperature that metal Ru was formed.It is above the temperature of 450-550℃ at which the Ti anode was commonly prepared.The ultrafine SnO2 effectively destroyed the preferred orientation structure of RuO2,which improved the dispersing abilities and sizes of powders and would control the growth tendency of RuO2.The surface areas of the powders heated at 400℃ for 1h were bigger than that of 600℃.The powders using SnCl2 as precursor had a bigger surface area than that of SnCl4.
HU Chun-tian, CHEN Sheng-li, DONG Peng, WANG Ai-jun, HU Yu. Preparation and Characterization of Three-dimensional Ordered Porous SnO2 Films[J]. Journal of Materials Engineering, 2008, 0(10): 232-235.
Three-dimensional ordered porous SnO2 films were prepared through first filling SnO2 into colloidal crystal templates formed by ordered packing of monodisperse polystyrene(PS) microspheres synthesized by emulsion polymerization of styrene,and then calcining the SnO2/PS composite films to remove the PS spheres.The colloidal crystal templates were prepared by assembling the particles through a vertical deposition technique at 55℃ and the filling process was accomplished by the use of dip-drawing method and liquid phase infiltration(LPI) method.Experiments showed that the quality of three-dimensional ordered porous SnO2 films prepared by modified LPI method was better than that prepared by dip-drawing method.Shrinkage occurred during the calcination to remove the PS template.
LENG Liang, SUN Kang-ning, ZHAO Yan. Influence of Hydrothermal Aging on Properties of Fe3O4 Nanoparticles[J]. Journal of Materials Engineering, 2008, 0(10): 236-238,242.
Magnetic Fe3O4 nanoparticles prepared by the method of coprecipitation were aged by hydrothermal treatment,and charaterized by X-ray diffractometer(XRD),Transmission Electron Microscope(TEM) and Vibrating Sample Magnetometer(VSM).XRD patterns and TEM images respectively showed that the constituent was pure phase of Fe3O4 and the crystallinity got improved after aging.The mean size of the particles was found to be about 20nm.It could be seen from the magnetic hysteresis loops that the magnetic properties of Fe3O4 nanoparticles improved after hydrothermal aging.
ZHUANG Yuan-yuan, SI Xiao-juan, CHEN Jian-jun, CHENG Dan-dan, Jeong Cheol Kim, WANG Yi-min. Study on Crystallizability and Crystallization Activation Energies of UHMWPP/UHMWPE Composite Fiber[J]. Journal of Materials Engineering, 2008, 0(10): 239-242.
The kinetics of non-isothermal crystallization of UHMWPP(ultra-high molecular weight polypropylene)/UHMWPE(ultra-high molecular weight polyethylene) composite fiber was studied by means of differential scanning calorimetry(DSC).Avrami equation and a combination of Avrami-Ozawa(Mo methods) were used to analyze the crystallizability and the crystallization activation energies.The values of F(T) and ΔE showed that the crystallization activation energies decreased with the contents of UHMWPE.UHMWPE act as nucleating agent to speed the crystallization of the UHMWPP/UHMWPE composite fiber.
CHEN Xin, CHEN Shu, HUANG Wei, LI Ze-lin. Fabrication of Porous Bismuth Films by Electrodeposition with Hydrogen Bubble Dynamic Templates and Redox Potential Pulses[J]. Journal of Materials Engineering, 2008, 0(10): 243-246,250.
Micro/nano-porous bismuth films and nano-porous bismuth films have been prepared by electrodeposition with hydrogen bubble dynamic templates and by redox potential pulses,respectively.The morphology,structure and component of the two kinds of films were characterized by scanning electron microscope(SEM) and X-ray diffraction(XRD),respectively.These films demonstrated high activity to the electrochemical reduction of 4-nitrophenol(4-NP).
WANG Ying-long, ZHANG Heng-sheng, CHU Li-zhi, DING Xue-cheng, FU Guang-sheng. Influence of Ambient Gas on Average Size of Si Nanoparticles Deposited by Pulsed Laser Ablation[J]. Journal of Materials Engineering, 2008, 0(10): 247-250.
The nanocrystalline silicon films containing nanoparticles were prepared by pulsed laser ablation in different ambient gas.Surface morphology of the Si film was observed by scanning electron microscopy(SEM) and was found that the average size of Si nanoparticles prepared in different gas all increased initially and then decreased with distance between the target and the substrate increasing.The average size of Si nanoparticles was the smallest under the condition of Ne ambient gas.
YU Cheng-wei, SONG Xiao-yan, LU Nian-duan, LI Er-dong. Preparation and Properties Characterization of Nanocrystalline Al[J]. Journal of Materials Engineering, 2008, 0(10): 251-253,256.
Pure Al nanocrystalline bulk with high relative density,small grain size and homogeneous grain size distribution was prepared by combing the hydrogen-arc condensation and spark plasma sintering in an entirely closed system filled with the inert gas.It shows that in the Al nanocrystalline bulk structure,the nanograin boundaries are clean without any other phases.The measured mechanical properties of the Al nanocrystalline bulk show that the micro-hardness has a value of 2.12GPa,which is about 6 times higher than that of the polycrystalline bulk,while the elastic modulus increases only a little as compared with the polycrystalline bulk.
GUAN Fei-fei, YAO Lan-fang, XIE Fu-jiang, TIAN Lin-lin, FANG Xue-ling, PU Sheng-li. Preparation and Magnetic Properties of α-Fe2O3/SiO2 Nano-composites[J]. Journal of Materials Engineering, 2008, 0(10): 254-256.
The α-Fe2O3/SiO2 nano-composites were prepared by the sol-gel method using TEOS,Eth,Fe(NO3)3·9H2O and HCl as raw materials.It was revealed that heat treatment temperature and content of Fe2O3 were crucial factors for the formation and magnetic properties of the α-Fe2O3/SiO2 nano-composites.The results indicated that the preferable heat treatment temperature and content of Fe2O3 were around 700℃ and 40%(mass fraction),respectively.
GUAN Jie, WANG Zong-hua, SUN Xi-quan, ZHANG Fei-fei, XIA Yan-zhi. Enhancing Spectral Probe Based on the Synergic Effect of Carbon Nanotubes and PVA for the Sensitive Determination of Heparin[J]. Journal of Materials Engineering, 2008, 0(10): 257-260,264.
The carbon nanotubes(CNTs) were regarded as a novel kind of enhancing agent to improve the effect of spectral probe,and a novel fading spectrophotometric method with the synergic effect of CNTs and PVA for the determination of Hep with Ethyl Violet(EV) is proposed in the present paper.The mechanism of the synergic effect of CNTs and PVA was discussed in this work.The ion association complex of Hep and EV noncovalented with CNTs through π-stacking,the hydrophilic property of which was improved in the presence of PVA.Comparative experiments showed that ΔAmax of EV with Hep increased by 330.7% at 640nm in the presence of CNTs and PVA.The apparent molar absorptivity was 4.29×106L·mol-1·cm-1.The linearity of the Hep in mass concentration ranges from 0-2.5mg/L of solution with a correlation coefficient of 0.9991.This method has been successfully applied to the determination of Hep in Heparin injection.
DU Wen, YE Yin-ping, LI Hong-xuan, CUI Hai-xia. Preparation of Anatase TiO2 Nanofilm by Magnetron Sputtering and Their UV-vis Spectrum Analysis[J]. Journal of Materials Engineering, 2008, 0(10): 261-264.
The anatase TiO2 nanofilms with different thickness were prepared by magnetron sputtering.Detailed structural characterization of the films were carried out using XRD,FE-SEM method.The films UV-vis spectrum of transmittance were measured and analysised.The optical energy band gap of the as-obtained nanofilms were calculated.The calculated optical energy band gap were close to the theoretical value with 3.2eV.
ZHU Kan, CHEN Wan-ping. Comparison Between Spark Plasma Sintering and Conventional Sintering of(Ba,Sr)TiO3 Ceramics[J]. Journal of Materials Engineering, 2008, 0(10): 265-267,271.
(Ba,Sr)TiO3 powders were synthetic in both Spark Plasma Sintering(SPS) method and conventional method at the temperature 1200-1300℃,respectively.The result revealed that the sample which prepared in SPS method was always has a higher dielectric constant with a relatively low dielectric loss at a specific temperature.Also the SEM photos showed the densification of ceramic surface could be improved through the rapid sintering of SPS.Moreover,we observed that 1240℃ is the best temperature for sintering after we tried several others.
CHENG Cheng, XUE Cui-ling, SONG Ren-guo. Effect of Ambient Pressure on Germanium Nanofilms Prepared by a Pulsed Laser Deposition[J]. Journal of Materials Engineering, 2008, 0(10): 268-271.
Using a pulse laser deposition technology,the Ge nanofilms are prepared on Si substrate in various ambient pressures of Ar gas.The effect of microstructures morphology and film thickness of the nanofilms is studied by a X-ray diffraction and a scanning electron microscope,respectively.Such Ge nanofilms obtained are all crystallized in the experiment.Further,the observed surface configuration of the films is evolved from the embedded quantum dots as usual to the net-like assembled nanoparticles with the increase of the ambient pressure,while the film thickness is reduced in our experiment.
FENG Jiao, REN Shen-yue, CHEN Ming-qing, NI Zhong-bin. Synthesis and Catalytic Property of Loaded Platinum Nanoparticles[J]. Journal of Materials Engineering, 2008, 0(10): 272-274,277.
The PNIPAAm grafted poly(acrylonitrile/styrene)(PNIPAAm-g-PAN/PSt) microspheres were prepared through the dispersion copolymerization.Using H2PtCl6 as metal source,platinum nanoparticles can be easily prepared via the reduction of the corresponding platinum ions Pt4+ by ethanol when the coordination interaction took place between the Pt4+ ions and amide of PNIPAAm,the ultrafine dispersed platinum nanoparticles were loaded on the surfaces of these PNIPAAm-g-PAN/PSt microspheres with unusual morphology.This material can be used in catalytic reactions such as aniline polymerization and so on.The polymerization rate of aniline can be controlled by changing reaction temperature.
LIU Dong-hui, SI Xiao-juan, CAO Ling-ling, WANG Yi-min. Study on the Elasticity and Crystallization Properties of Poly(ether amide)-modified PA6[J]. Journal of Materials Engineering, 2008, 0(10): 275-277.
With the method of block polymerization with polyether amide,we got the poly(ether amide)-modified PA6 fiber.The polymerization,spinning and elasticity,crystallization properties of modified PA6 were investigated.It is found that with increase of polyether amide volume,the modified PA6 exhibits better elasticity and resiliency,and also the increase of crystallization temperature.
YANG Yang, TIAN Jing-hua, LUO Zhong-zi, WU Sun-tao, TIAN Zhong-qun. Fabrication of Suspended Electrodes Pair with Nanometer-sized Gap on Chip for Measuring Electrical Properties of Single Molecules[J]. Journal of Materials Engineering, 2008, 0(10): 278-282,286.
For studying molecular devices,we fabricated electrodes pair with a nanometer-sized gap on chip by combining photolithography and electrochemical technique.Using the thermal oxidation SiO2 layer and polyimide(PI) layer as sacrifice layer materials respectively,we made the electrodes pair suspends from the substrate which is available for the mechanically controllable break junction(MCBJ) method.On the basis of this progress,the success rate in the MCBJ experiment has been improved and the available life of microchip used in the MCBJ experiment has also been prolonged.With combination of self-assembling(SAM) and MCBJ methods,few molecules of benzene-1,4-dithiol(BDT) were connected to the two ends of the electrodes pair to form the metal-molecule-metal junction,then the conductance of single molecules and its I-V curves were measured.
HAN Bin, WU Guang-ming, XING Guang-jian, WANG Yi, JIANG Wei, LI Dong-lin. Growth and Characterization of N-In Codoped ZnO Films Deposited on Glass Substrates[J]. Journal of Materials Engineering, 2008, 0(10): 283-286.
N-In codoped zinc oxide films were deposited on glass substrates by ultrasonic spray pyrolysis(USP) technology.CH3COONH4 and In(NO3)3 were used as the sources of N and In,respectively.The effect of N-In codoping and depositing temperature on structure of ZnO films was studied by using X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),Hall measurement,and optical property was investigated by UV spectrophotometer.It is found that structural and electrical properties of ZnO thin films change dramatically due to N-In codoping,but the n-type conductivity of them are contrary to the relevant document.
GUO Li, WANG Dan-jun, LI Dong-sheng, HUANG Jing, WANG Ji-wu. ZnS Microspheres:Hydrothermal Preparation and Photocatalytic Activity[J]. Journal of Materials Engineering, 2008, 0(10): 287-290,295.
ZnS microspheres were prepared via hydrothermal method with zinc nitrate as zinc source,(NH2)2CS and CH3CSNH2 as sulphur source and CTAB as soft template.XRD,XPS,SEM and UV-vis techniques were used for characterization.Results of structural characterization indicated that the as-prepared samples belonged to cubic sphalerite crystal phase ZnS.The images of scanning electron microscopy showed that the well-dispersed ZnS microspheres were obtained and microspheres were comprised of ZnS nanoparticles with diameter 20-30nm.When the sulphur source was CH3CSNH2 and(NH2)2CS,the diameter of as-prepared ZnS microspheres was 500-1000nm and 1.5μm respectively.UV-Vis absorption spectra demonstrated that ZnS microspheres had strong absorption band between 200 to 320nm.Using ZnS samples as photocatalysts,photodegradation of Rodamine B was investigated.
ZHOU Da-peng, DU Zhi-ping, ZHAO Yong-hong, ZHANG Guang-liang. Study on Surface Modification of nano-sized Magnesium Hydroxide by Polyacrylate Sodium[J]. Journal of Materials Engineering, 2008, 0(10): 291-295.
The surface modified nano-sized magnesium hydroxide was prepared by direct precipitation method with magnesium nitrate,sodium hydroxide and polyacrylate sodium as raw materials.The influence of reaction temperature,reaction time,concentration of magnesium nitrate,dosage of polyacrylate sodium on average particle size and sediment volume were discussed.The optimum conditions were confirmed.The modified and unmodified samples were characterized by fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD) and transmission electron microscope(TEM).The results indicate that polyacrylate sodium was adsorbed onto the surface of nano-Mg(OH)2,the main XRD diffraction peak of the nano-Mg(OH)2 was strengthened showing low agglomeration of the prepared samples.
LIU Mei-ling, LIAN Yong-fu, ZHANG Xiang-yu, ZHANG Jian-guo, GUO Li-hua, GONG Li-hong. Modification of Single-walled Carbon Nanotubes by Ammonium Sulfamate[J]. Journal of Materials Engineering, 2008, 0(10): 296-298,302.
Water-soluble single-walled carbon nanotubes were prepared by successive ammonium persulfate oxidation and ammonium sulfamate chemical modification.Raman spectrum and UV-vis-NIR absorption spectrum show that the above procedure does not change the electronic structures of single-walled carbon nanotubes.Moreover,the infrared spectrum confirms the formation of amide bond between ammonium sulfamate and carbon nanotubes.Such water-soluble single-walled carbon nanotubes might be applicable in biochemistry and biomedicine.
WANG Jin-gang, PENG Ru-fang, ZHU Gen-hua, YU Hai-jun, CHU Shi-jin,. Research Progress of Combustion Synthesis of Fullerenes[J]. Journal of Materials Engineering, 2008, 0(10): 299-302.
The summary of formation mechanism of fullerene by combustion method was presented.C/O ratio,burning furnace pressure,type of gas dilution,the distance of flame from the nozzle,gas velocity at burner,the flame temperature on the impact of fullerenes yield were discussed.
ZHANG Wen-neng, LIU Hong-fang, HUANG Qing-wu, WU Heng-liang, HUANG Lei, WU Run. Al-doped Nano-ZnO Nanowhiskers and Its Photocatalysis Properties in Aqueous Solution[J]. Journal of Materials Engineering, 2008, 0(10): 303-305.
ZnO nanowhiskers and its Al-doped ones were analysized by XRD,TEM and HTEM.Al ions were doped into crystal by thermal physical method,but for photoreduction method they deposited on the surface of the nanowhiskers.Al-doped ZnO has effective improvement on photocatalytic degradation for methylene blue.Especially,when Al ions were in the crystal of ZnO,the nanomaterials have best photocatallytic properties with decoloration rate of 93.3 and absorbance of 0.103.
LI Xiao-li, BAO Wei-ren, ZHU Zi-ping. Synthesis of Carbon Nanotube by Methane Decomposition Using Arc Plasma Jet[J]. Journal of Materials Engineering, 2008, 0(10): 306-307,311.
Carbon nanotubes(CNTs) were produced by arc plasma jet by methane decomposed with dosing Co2O3 as catalyst.The products were characterized by scanning electron microscopy(SEM) and high resolution transmission electron microscopy(HRTEM).The experimental results revealed that large scale and high purity carbon nanotubes were produced in the solid phase,with the diameter of the CNTs distributing in 50-90nm.And a carbon nanotube with uneven wall thickness was produced whose wall was symmetrical thick-thin-thick style.
SHI Yue-gang, CHEN Shi, XIE Hong-yong, ZHANG Wei. Effect of Operating Conditions on TiO2 Nano-particle Sizeand Crystal Form[J]. Journal of Materials Engineering, 2008, 0(10): 308-311.
The CVD method is used to produce TiO2 nano-particles in the propane-air diffusion flame.The effect of different operating conditions on size and crystal form is investigated.There are four different operating conditions analyzed.The results show that temperature is influenced mainly by the flow rate of propane and air;besides the higher the flow rate of carrier gas is,the lower the content of rutile is,while the particle size is little changed;meanwhile the influence of the flow rate of TiCl4 on crystal content is negligible and particle size is in proportion to the flow rate of TiCl4.
ZHANG Fei-fei, WANG Zong-hua, SUN Xi-quan, XIA Yan-zhi. Electrochemical Behaviors of Ascorbic Acid and Dopamine on Morin Incorporated Carbon Nanotubes Modified Electrode[J]. Journal of Materials Engineering, 2008, 0(10): 312-315.
A novel modified electrode(morin/MWNTs/GCE) was constructed by electro-polymerizing morin onto multi-walled carbon nanotubes on the surface of glassy carbon electrodes.Taking dopamine(DA) and ascorbic acid(AA) as model compounds,the modified electrode showed good electro-catalytic effect,at the same time the mechanism was studied.The oxidation peak current of DA and AA were the biggest than that at bare and MWNT modified electrodes,with the anodic peak potential difference(ΔEpa) was 210mV.A differential pulse voltammetric technique for measurement of dopamine over the range of 1.0×10-7~5.0×10-4mol/L had been developed in the presence of AA.The detection limit was 2.0×10-8mol/L.
WANG Shu-dong, YIN Gui-bo, ZHANG You-zhu, WANG Hong-wei, JIANG Xin-jian, DONG Zhi-hui. Structure and Biomechanical Properties of Electrospun PLA Tubular Scaffold[J]. Journal of Materials Engineering, 2008, 0(10): 316-320.
Biocompatible and biodegradable polylactide(PLA) was used as material,the small-diameter(d=4.5mm) PLA tubular scaffold was fabricated via electrospinning which was performed on a high-speed rotating mandrel-type collector.The morphology,porosity and biomechanical affected by technical parameters were investigated.The results showed that the fiber diameter increased graudally,porosity decreased and its breaking intensity increased with the increasing of the spinning solution concentration.When the rotating speed was 2000r/min,aligned fibers could be obtained,and the scaffold got the least porosity and largest breaking intensity,and the burst pressure strength of the scaffold was high than the normal blood pressure in human body.As the thickness of the wall increased,the breaking intensity and burst strength of the scaffold both increased gradually.
YU Hai-jun, PENG Ru-fang, WANG Jin-gang, ZHU Gen-hua, JIN Bo, CHU Shi-jin,. Selective Synthesis of Gd-endohedral Fullerenes and Single-wall Carbon Nanotubes by Using GdNi2 Alloy[J]. Journal of Materials Engineering, 2008, 0(10): 321-323,327.
Gd-endohedral fullerenes and single-wall carbon nanotubes(SWNTs) were selectively synthesized with arc discharge method under different helium pressure,respectively,by using GdNi2 alloy as the origin of metal.When the He pressure was 16kPa,Gd-endohedral fullerenes were mainly obtained,meanwhile,the He pressure was 80kPa,single-wall carbon nanotubes(SWNTs) were selectivity synthesized.
QIU Yang, XIA Hai-ping. Preparation of Nano-hydroxyapatite by Novel Ultrasonic Atomization Precipitation Method[J]. Journal of Materials Engineering, 2008, 0(10): 324-327.
At room temperature and normal atmospheric pressure,the hydroxyapatite nano-powders were prepared by ultrasonic atomization precipitation method and with Ca(NO3)· 4H2O and(NH4)2HPO4 as raw materials.The obtained powders were homogenous and in size of 30-40nm.The effects of the reaction time,the sintering temperature on the crystal morphology of HAP and homogeneity were investigated.The obtained HAP powders were compared with those synthesized by the conventional ultrasonic method and traditional chemical precipitation method under the same conditions.The results revealed that the method taken in the experiment can shorten reaction time to make HAP nano-powders,enhance the synthetic efficiency effectively and crystallinity of HAP nanopowders in a relatively short reaction period,moreover,the obtained nano-particles were more homogenous.
XU Pu, GAO Shan-min, YU Zhong-xi, HUANG Bai-biao, DAI Ying, XU Yan-bin. Hydrothermal Synthesis and Photocatalytic Activity of Fe3+ Doped Nano-TiO2[J]. Journal of Materials Engineering, 2008, 0(10): 328-331,335.
Fe3+ doped nano-TiO2 were prepared by hydrothermal method using butyl titanate and Fe(NO3)3·9H2O as precursor.X-ray Diffraction(XRD),Transmission Electron Microscope(TEM) and UV-Vis Absorbance Spectroscopy were used to characterize the products.The photocatalytic activity of Fe3+ doped nano-TiO2 at the different amount of catalyst and pH values on the degradation of methylene blue(MB) were studied under 300W halogen tungsten light.The results show that the photocatalytic activity of Fe3+ doped nano-TiO2 is better at alkaline condition and the best amount of Fe doped nano-TiO2 is 1.0g/L.The band gap of Fe doped nano-TiO2 become narrow and the absorption red-shifted and the absorption intensities increased.At the same time,the recombination of e-/h+ was inhibited,so the photocatalytic activity of Fe doped nano-TiO2 are enhanced.
SUN Cai-hong, LI Chang-sheng, YU Ying-ming. Template Synthesis and Friction Properties of MoS2 Nanotubes[J]. Journal of Materials Engineering, 2008, 0(10): 332-335.
In order to study the friction properties of MoS2 nanotubes,which were prepared by thermal decomposition(NH4)2MoS4 at low-temperature(450℃) using template method.The morphology and microstructure of as-obtained MoS2 were characterized by scanning and transmission electron microscopy(SEM/TEM),energy dispersive spectroscopy(EDS) and atom force microscopy(AFM).The results show that as-obtained MoS2 nanotubes have uniform diameters of about 100nm and are more than 5μm in the length,which corresponds closely to the parameter of the pore.The friction experiment was made at CETR UMT-2 examination machine and it could be concluded that MoS2 nanotubes possess excellent lubricate capability.
ZHAO Ai-ming, ZHANG Ge-xin. Molecular Dynamics Simulation of Interaction Between Category of Superacid Catalyst and Methyl-mercaptoacetate[J]. Journal of Materials Engineering, 2008, 0(10): 336-338.
In order to find the catalyst that can replace the sulfate in the esterification reaction of the methyl-mercaptoacetate,the molecular dynamics simulation of the interaction between the category of the superacid catalyst,mercaptoacetic acid and methanol at different temperature was carried out with opls force field by hyperchem 7.5 soft in this paper.Analyzed the potential energy data,their suitable temperature range is 310-340K,and SO4-2/ TiO2 is able for better response as their catalyst.
SI Xiao-juan, CHEN Jian-jun, CHENG Dan-dan, JEONG Cheol Kim, WANG Yi-min. Study on Mechanical Property of Gel Spun UHMWPP Fiber[J]. Journal of Materials Engineering, 2008, 0(10): 339-341.
A novel polypropylene(PP) fiber was prepared by using gel spinning from dilute solutions of ultrahigh molecular weight isotactic polypropylene(i-UHMWPP),and subsequently drawing at various temperatures draw ratio.Effects of drawing temperature on the mechanical property of the resulted fibers were investigated.The results showed that the tensile behavior of UHMWPP fiber belongs to crystalline polymer at room temperature low draw ratio,but hard elastic materials at high temperature.The fracture stress and Young's modulus are decided by draw ratio and independent of our set drawing temperature,however breaking elongation is decided by the both.
LIU De-fei, ZHENG Yu-ying, HUANG Hui-min. Hydrothermal Synthesis and Characterization of Core-shell TiO2/Al2O3 Nano Material[J]. Journal of Materials Engineering, 2008, 0(10): 342-345.
Core-shell nanometer TiO2/Al2O3 particles were prepared by one-step hydrothermal method,the effects of pH,temperature and time for hydrothermal process on the performance of the resulting powders were studied.The optimized reaction parameters were on the follows:The precursor's pH about 9.0 hydrothermal temperature of 260℃ holding for 3.5h.The average particle size of the product was also smaller than 20nm.The nanometer TiO2/Al2O3 particles prepared by one-step hydrothermal are well cored though the XRD,TEM and SEM characterization.The preparation also can improve the aging resistance of emulsoid.
REN Qi, LU Ting, CHEN Ming-qing. Study on Properties and Preparation of PAA-PMMA Magnetic Microspheres with Crosslinking Structures[J]. Journal of Materials Engineering, 2008, 0(10): 346-349.
Fe3O4 nanoparticles were synthesized by chemical co-precipitation.Then adding a mount of sodium oleate to modify the surfaces of the nanoparticals to obtain the oil-base Fe3O4 nanoparticles which average diameter was 12.7nm.The core-shell structured magnetic composite microspheres with poly(acrylic acid)-co-poly(methyl methacrylate)(PAA-PMMA) as shell and Fe3O4 as core were prepared by dispersion polymerization using divinylbenzene(DVB) as cross-linking agent,2,2'-azobisisobutyronitrile(AIBN) as initiator,poly(vinylpyrrolidone)(PVP) as stabilizer in the presence of oil-base Fe3O4 nanoparticles.The effect of the ratio of ethanol to water,amount of AIBN,PVP and DVB on the microsphere formation were investigated.The optimum recipe was finally obtained.The structures,morphologies,diameter,diameter distribution and magnetic amount of the magnetic composite microspheres were characterized.
WANG Nuan-xia, SUN Cheng-hua, HU Xiu-jie, CHEN Ping, ZHOU Shu-yun. Fabrication of ZnO/TiO2 Heterojunctions Via a Facile Two-step Method[J]. Journal of Materials Engineering, 2008, 0(10): 350-352.
Three-dimensional ZnO/TiO2 hierarchical structures with high density of secondary ZnO nanostructures grown on primary TiO2 fibers were obtained by the combination of electrospinning and hydrothermal technique.The dependence of the nanorods scales with the reaction time was investigated.The as-prepared samples were studied by SEM,TEM and XRD,respectively.
PENG Si, YAN Hua, LIU Shan-tang. Coating Process of PVP Layer on Nearly Monodisperse Aqueous Dispersions of Gold Nanoparticles[J]. Journal of Materials Engineering, 2008, 0(10): 353-355.
The coating process of the poly(vinyl-pyrrolidone)(PVP) layer on nearly monodisperse aqueous dispersions of gold nanoparticles was studied by UV-Vis absorption spectroscopy.The obtained results demonstrated that the position of the absorption peak of the gold nanoparticles had a redshift of 15nm when PVP was adsorbed on the surface of the gold nanoparticles.A possible mechanism of the coating process of the PVP molecules on nearly monodisperse aqueous dispersions of gold nanoparticles was proposed on the basis of the amount of PVP added in the gold colloid and the shift of absorption peak.
Menggentuya, CAO Xing-Hui, JIA Mei-lin, BAO Zhaorigetu. Preparation of Nano Au/Fe2O3-MOx Catalyst and Its Catalytic Performance for CO Low Temperature Oxidation[J]. Journal of Materials Engineering, 2008, 0(10): 356-357,362.
A series of Au/Fe2O3-MOx(M=La & Ce) catalysts were prepared by deposition-precipitation method and the catalytic performance for CO low temperature oxidation over these catalysts was investigated.In order to analysis the influence of the addition of rare earth oxide,these catalysts were characterized by XRD,BET and AAS.The results indicated that the addition of CeO2 could improve the activity while no obvious effect was found with addition of La2O3.
ZHAO Yuan-bi, QIU Zu-min, LIU Zhong-wei, HUANG Jia-ying. Preparation and Characteristics of Composite Magnetic Chitosan Microspheres Used as Carrier of Targeted-drug[J]. Journal of Materials Engineering, 2008, 0(10): 358-362.
Using FeCl3·6H2O and FeCl2·4H2O as reactants and NH4OH as precipitation reagent,the magnetic Fe3O4 nanoparticles were prepared by chemical co-precipitation.And then using the emulsification cross-linking technique to got composite magnetic chitosan microspheres was got by adding proper amount of glutaraldehyde into chitosan solution which contains dispersed Fe3O4 nanoparticles.The average size of prepared composite magnetic microsphere was about 10μm,due to the spherical,dispersive,magnetic-responsive and biodegradable characteristic,the composite magnetic chitosan microsphere can be used as functional material or carrier for targeted delivery of drugs.
FAN Wei-wei, LÜ Yong-kang, BAO Wei-ren, ZHAO Juan, FAN Bao-yun. Preparation of Coal-based Carbon Nanotube with FeS-Co2O3 as Catalyst[J]. Journal of Materials Engineering, 2008, 0(10): 363-365,369.
Carbon nanotubes were synthesized from coal by arc discharge method with FeS-Co2O3 as catalyst.The effect of catalyst on the generation of carbon nanotubes was investigated.As-prepared CNTs were characterized by SEM,HRTEM,Raman spectroscopy techniques.The results showed that carbon nanotubes can get a high quality when the ratio of coal:FeS:Co2O3 was 1:0.3:0.3.And the effects of catalyst on the Yangcheng coal and Datong Coal were similar.In addition,the effects of FeS and Co2O3 in the growth of carbon nanotubes were also proposed.
MA Shi-yu, ZHENG Shao-hua, GUO Hong-na, DING Hai-yang. Surface Modification of Amorphous ZrO2 Nano-particles[J]. Journal of Materials Engineering, 2008, 0(10): 366-369.
At first,57nm ZrO2 was produced by the sol-gel methods.The nano-meter ZrO2 was modified with KH-560,KH-570,A151,titanate and stearic acid.Then the powder was analyzed by laser particle analyser,IR pattern,SEM,TEM,XRD.Results indicated that A151 was the best modifier,surface-modified nano-particles ZrO2 had a good dispersity in organic solvents exhibit a rather uniform size distribution.
XUE Liang, LI Huai-xiang, YU Lei, HU Ming-bo, CHEN Shan-shan. Study of Porous Silicon Treated by Silver Nitrate Solution[J]. Journal of Materials Engineering, 2008, 0(10): 370-373,377.
Porous silicon(PS) was formed by etching n type silicon photo-electrochemically and its visible photoluminescence(PL) was affected by immersing in silver nitrate solution.Self-assembled silver nano-islands on the surface of immersed PS has been obsevered by scanning electron microscopy(SEM).Measurement results of Fourier transform infrared(FTIR) spectroscopy and the X-ray photoelectron spectroscopy(XPS) showed that PL enhancement of the PS might be attributed to Si-O structure,which was formed by the interaction between the rare silver islands and silicon and played effective luminescence centers.And the PL intensity decayed more dramatically with the increasing concentration of the silver islands which are non-radiative carrier-recombination centers.
AN Qing-qing, HU Si-xiao, WANG Yan-ping, WANG Yi-min. Preparation of Mesoporous Silica SBA-15/Hyperbranched Polyurethane Hybrids and Its Structure and Properties[J]. Journal of Materials Engineering, 2008, 0(10): 374-377.
SBA-15/HPU hybrids was synthesized by grafting hyperbranched polyurethane on the surface of amine-modified mesoporous silica SBA-15.XRD,FTIR,SEM,TEM,BET,TGA were used to characterize the microstructure of the hybrids obtained.The results show that,hyperbranched polyurethane has been successfully grafted onto the surface of mesoporous silica SBA-15(mass fraction of organic load is about 30%).Furthermore,the grafting of organic moieties don't destroy the pore structure of SBA-15,hybrids still keep the high ordered hexagonal mesostructure with the decrease of pore volume,pore diameter and surface area in a certain extent.Chemical reaction activity of mesoporous SBA-15 was effectively increased by grafting a mass of end group.
