Jorunal of Functional Materials

Select

Progress in Research on Synthesis Methods and Growth mechanism of Aligned Carbon Nanotubes

XU Xian-feng;HONG Long-long

. 2013, 44(02): 153-156.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Progress in research on synthesis of aligned carbon nanotubes are summarized in detail at home and abroad in this paper.The preparation methods of aligned carbon nanotubes are introduced,especially templated synthesis,and the growth mechanism is also presented.The existing problems in China and research prospect on CNTs around the world are briefly described.

Select

Preparation and Properties of acrylic acid and acrylamid superabsorbent copolymer

LIU Yu-gui;ZHANG Jin;ZHU Zhong-qi;LIU Qiang;LIU Qing-ju

. 2013, 44(02): 157-160.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The acrylic acid and acrylamide (PAA-AM) superabsorbent copolymer was synthesized by inverse-suspension polymerization with cyclohexane as dispersant, Span80 as suspension stabilizer, acrylic acid (AA) and acrylamide (AM) as comonomer, potassium persulfate as initiator, N,N'-methylene-bis-acrylamide as crosslinking agent. The influence of neutralization degree of AA, mass ratio of acrylic acid (AA) to acrylamide (AM), the amount of crosslinking agent and initiator, and reaction temperature on the absorption capability of water and salt solution were investigated. The results show that the water absorbency of the superabsorbent polymer prepared at the optimum condition in deionized water and in 0.9%NaCl solution is about 1282g/g and 109g/g, respectively, and under the same conditions, The sample has more excellent water absorption and salt-resistance, which compares with the similar products of the SNF (French) production.

Select

Zinc oxide nanopowders prepared by microwave-hydrothermal method

LIU Gui-xiang;XIE Ming;XU Guang-liang;LUO Qing-ping;LAI Zhen-yu;MA Han-bing

. 2013, 44(02): 161-165.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Using zinc nitrate and sodium hydroxide as raw materials, ZnO nanopowders were successfully prepared by microwave-hydrothermal method. The product prepared by the microwave-hydrothermal method was characterized by X-ray diffraction(XRD), scanning electron microscope (SEM), laser particle size analysis and specific surface analysis. The influencing factors such as the pH value of solution, the microwave-hydrothermal reaction temperature and reaction time were discussed in detail. The results showed that the pH value of solution and the microwave-hydrothermal reaction temperature had great effect on the particle-size distribution of powders prepared. The optimum process conditions of ZnO nano-crystal prepared by the microwave-hydrothermal method were the pH value of solution of 5, the microwave-hydrothermal reaction temperature of 130 ℃, and the reaction time of 10 min. The ZnO powder prepared at the optimum process conditions possesses the specific surface area of 18.53m2/g, the average particle size of 61 nm, the narrow granularity distribution and the high crystallinity.

Select

The deposition behavior of nHA induced by TiO2 nanotube array in simulated body fluid

TIAN Ang;XUE Xiang-xin;YANG He;RU Hong-qiang;WANG Mei

. 2013, 44(02): 166-171.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The TiO2 nanotube array (TNT) coatings with different caliber growing perpendicular to the titanium surface were prepared by electrochemical anodized method. The nHA/TNT composite coatings were fabricated by soaking in simulated body fluid (SBF). The forming process and mechanism were studied in this paper. Ti-OH functional group was the inducement of the nHA nucleary on the TNT. The matching structure between TiO2 and nHA could improve the nucleation rate of the nHA, the tubes with biphase mixed by anatase and rutile clearly induce nHA growth more efficient than that in their amorphous. The wettability of TNT was controlled by the caliber, and influenced the rate of nHA formation. The results indicated that enhancing the hydrophily of TNT could help to deposit nHA.

Select

Preparation，properties and mechanism of Ag-TiO2 photocatalyst

ZHANG Ying;YAN Ning-ning;ZHU Zhong-qi;ZHANG Jin;LIU Qing-ju

. 2013, 44(02): 172-176.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Abstract : The Ag-TiO2 photocatalysts were prepared by sol-gel method. The influences of different preparation condition on properties were studied. The photocatalytic activity of Ag-TiO2 was investigated by measuring the degradation rate of methylblue (MB) under the irradiation of fluorescent lamp. The results show that Ag doping broadens the absorption region to visible light and inhibits the recombination of the photo-generated electrons and holes. The photocatalytic activity of the sample with n(Ag):n(TiO2)=1:1000 and sintered temperature at 400℃ is the best under the irradiation of fluorescent light, and it is higher than that of Degussa P25. The mechanism of Ag doped TiO2 for enhancement of photocatalytic activity is analyzed.

Select

Research on Property of Absorptive Functional Fiber Based on Polymethacrylate Prepared via Reactive Extrusion and Melt-spinning

MA Xiao;XU Nai-Ku;XIAO Chang-fa;ZHAO Jian

. 2013, 44(02): 177-181.

Abstract ( )

Download PDF ( )

Knowledge map

Save

N-butyl methacrylate (BMA) homopolymer was synthesized by aqueous suspension polymerization using polyvinyl alcohol as a dispersing agent and benzoyl peroxide (BPO) as an initiator. BMA homopolymer melt and hydroxyethyl methacrylate (HEMA) monomer containing the initiator (BPO) were reacted in the twin-screw extruder by means of the reactive extrusion. Polymethacrylate fiber with three-dimensional network crosslink structure which was built by hydrogen bonding interactions of hydroxyl groups of HEMA in the macromolecules was prepared via melt spinning. The microstructure and related properties of the fiber samples were characterized through absorption performance test, gel fraction test, fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and differential scanning calorimetry (DSC). The results show that the comprehensive properties of the obtained fiber are best when the mass ratio of HEMA monomer to BMA homopolymer was equal to 3:7, and the saturated absorbency for trichloroethylene and chloroform are 12.16g/g and 10.97g/g, respectively.

Select

MA/AA/AM/AMPS quadripolymer inhibitor for sulphate and carbonate scales

MOU Jing;LI Xiao-rui;FEI Gui-qiang;Wang Hai-hua;SHUI Xiao-jun;YANG Shan-shan

. 2013, 44(02): 182-186.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Select

Synthesis and Properties of Cationic Polyacrylate Latex by Soap-Free Emulsion Polymerization

GAO Dang-ge;HOU Xue-yan;LV Bin;MA Jian-zhong

. 2013, 44(02): 187-190.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Polymer diallydimethyl ammonium chloride-butylacrylate-methyl methacrylate (PDMDAAC-BA-MMA) was prepared by emulsifier-free emulsion copolymerization .In single factor experiment method, the influence of synthetic conditions,such as the dosage of initiator, system temperature and the content of diallyldimethyl ammonium chloride on the properties of latex was investigated in details. The latex was characterized by Fourier Transform Infrared Spectroscopy(FT-IR), Dynamic Laser Scattering(DLS) and Transmission Electron Microscope(TEM). FT-IR indicated that polymerization was happened. DLS and TEM indicated that the average diameter of the polyacrylate latex particles was about 800nm with core-shell structure. Tensile strength, water absorption and dry and wet rub fastness of leather finished by PDMDAAC-BA-MMA was similar to leather finished by market products, elongation at break of leather was improved.

Select

The effect of carbon content on the electrochemical performance

GENG Hai-long;W Jun;JU Hua;LI Shen-fan;WANG Zhen-wei;XU Yan-hua

. 2013, 44(02): 191-193.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Select

Influence on polyacrylate emulsion and film performance on ketone-hydrazide crosslinking

ZHANG Juan;SHEN Yi-ding;WANG Hai-hua;FEI Gui-qiang

. 2013, 44(02): 194-196.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Polyacrylate emulsion containing active Keto groups was prepared by diacetone acrylamide as function monomer in periment .Then the coating used as air conditioning aluminum foil was obtained by blending polyacrylate emulsion and adipic dihydrazide. Crosslinking degree on the effect of film on the emulsion stability, waterresisting properties ,delimit resistance and corrosion resistance was diacussed.In addition, using FTIR to characterize the polymer. The results shows that, with the increase of the dosage of diacetone acrylamide，gel rate increases and stability becomes poor，the waterresisting properties ,delimit resistance and corrosion resistance increase,while thermal stability decreases.

Select

Study on swelling and drug release properties of biocompatible chitosan/montmorillonite composite microspheres

LI Zhi-hui;LIU Wen-tao;CUI Hai-tao;LI Zhong-yuan;GAO Xu-jing;HE Su-qin;ZHU Cheng-shen

. 2013, 44(02): 197-201.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Chitosan/montmorillonite composite microspheres with good biocompatibility were prepared by inverse emulsion polymerization, and modified montmorillonite was introduced as intercalation modifier. The structure of modified montmorillonite was analyzed by X-ray diffraction and infrared spectroscopy. Drug-loaded chitosan/montmorillonite microspheres were prepared with aspirin as the model drug by drug entrapment method and drug release properties were discussed. The results are as follows. The interlayer distance of modified montmorillonite becomes larger. The swelling rate and drug release rate of composite microspheres reduces with the content of montmorillonite increasing. The release mode of drug-loaded chitosan/montmorillonite microspheres is Fickian diffusion type at pH1.2. The release mode is non-Fickian diffusion type at pH7.4. Chitosan/montmorillonite composite microspheres have great potential as a drug carrier.

Select

Microstructure and Thermal Stability of an Ultrathin α-Ta(N)/TaN Bi-layer Diffusion Barrier

LIU Chun-Hai;CUI Xue-jun;JIN Yong-zhong;YANG Rui-song;WANG Su-juan;YE Song

. 2013, 44(02): 202-205.

Abstract ( )

Download PDF ( )

Knowledge map

Save

An ultrathin α-Ta(N)/TaN bi-layers diffusion barriers with lower resistance were prepared by a magnetron sputtering method with using low N concentration. This deposition method can avoid effectively the high resistivity of bi-layer barrier films resulted from the N integration and the introduction of heterogeneous elements for the formation of ultrathin α-Ta. Four-point probe (FPP), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for characterization of the diffusion barriers microstructure before and after annealing The results show that the as-deposited α-Ta(N)/TaN bi-layer films have lower resistivity and good crystallinity，and the α-Ta(N)/TaN bi-layer diffusion barrier has an excellent thermally stability. Its failure temperature can be up to 600 °C

Select

Preparation of ultra-fine silver powder for solar cell grid electrode

LI Ji;HUANG Hui;GUO Zhong-cheng

. 2013, 44(02): 206-211.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Select

Study on the performance and of hydrophobic starch modified by ASA and its application as surface sizing agent

YANG Xiao-wu;SHEN Yi-ding;LI Pei-zhi;HUANG Fang

. 2013, 44(02): 212-215.

Abstract ( )

Download PDF ( )

Knowledge map

Save

In order to prepare a kind of environment-friendly surface sizing agent, the starch was modified by alkenyl succinic anhydride (ASA), and the performances were characterized by the infrared spectrum (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), surface tension meter and so on, and the surface sizing effect of hydrophobic starch modified by ASA was studied. The results showed that, the hydrophobic long chain was introduced onto the guar gum successfully, the morphology of starch granules changed. As the dosage of modified guar gum was 5%, the sizing degree was up to 206 seconds, and the dynamic contact angle (DCA) was more than 120°.

Select

Preparation and the Study of γ-ray Protective Properties of Activated Bi2O3 / rubber Composite

WEI Xia;ZHOU Yuan-lin;LI Ying-jun

. 2013, 44(02): 216-220.

Abstract ( )

Download PDF ( )

Knowledge map

Save

By adding different surfactants and using mechanical milling method, in this study, we prepared the activated Bi2O3 micro/nano powder with uniform particle size distribution, and then added them into natural rubber latex in the form of slurry to prepare the activated Bi2O3/ rubber composites with good mechanical properties and γ-ray protective performance. Using the laser particle size analyzer, XRD, fluorescence(PL), FT-IR, SEM, electronic universal testing machine, NaI(Tl) detectors, this study analyzed and characterized the chemical composition of the particles, particle size distribution, light-induced luminescence, the mechanical properties of composite rubber and γ-ray protective performance. The results showed the activated Bi2O3 particles modified by casein-based composite surfactants has average particle size of 120nm and good dispersion stability; The γ-ray shielding rate of activated Bi2O3/rubber composite increased to 23.97% at 241Am point source of 59.5keV γ-ray, the mechanical strength was significantly higher than those natural rubber without adding activated Bi2O3.

Select

Drug Loaded Microparticles with Core-Shell Structure and their Drug Release Property

;;Jianhua Rong

. 2013, 44(02): 221-225.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Core-shell drug loaded microspheres were prepared by the layer-by-layer self-assembly technique in which sodium polystyrene sulfonate (PSS), poly(diallyl dimethyl ammonium chloride) (PDDA) and clay particles (laponite) were alternatively adsorbed on the calcium carbonate (CaCO3) template particles. PSS was also used in the preparation of CaCO3 template to control its structure. Ibuprofen (IBU) as model drug was then loaded in the pore of CaCO3 through physical absorption. At last the polyelectrolytes and/or laponite particles were assembly on the drug loaded CaCO3 particles to block the drug releasing. The laponite could be dispersed into monolayer round sheet with the diameter and thickness about 25nm and 1nm respectively in the water, which used in the shell of microspheres here to promote the properties of drug releasing. The morphology, structure and drug release property of the microspheres were characterized by the scanning electron microscope (SEM), the transmission electron microscope (TEM), Zeta potential analyzer, X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR) and ultraviolet spectrophotometer (UV). The results showed that PSS played an important role in the synthesis of CaCO3 microspheres, by which not only the spherical morphology was controlled, but also its crystal type was changed from calcite to vaterite. The IBU loading in CaCO3 could reach 28.6mg/g. The thin shell of polyelectrolyte or polyelectrolyte/laponite could be formed on the surface of CaCO3 by layer-by-layer assembly, which was verified by the polyelectrolyte/laponite microcapsules obtained after removing the core of CaCO3. The result of cumulative drug releasing showed that the shell of polyelectrolyte and laponite particles could effectively extend the time of drug releasing.

Select

Study on Silk Fibroin/Nano-bioactive Glass porous Composite Scaffolds

XUAN Xiao-na;ZHU Hai-lin;CHEN Jian-yong

. 2013, 44(02): 226-231.

Abstract ( )

Download PDF ( )

Knowledge map

Save

In this paper, the silk fibroin/nano-bioactive glass(SF/NBG) porous composite scaffolds were prepared by freezing-drying and characterized by X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and Scanning electron microscopy(SEM). The results showed that SF/NBG composite scaffolds had better interconnected porous structures, and the pore size was about 150um to 300um, the porosity was between 80.6% and 90.3%. Simultaneously, the conformation of silk fibroin was promoted to change from random coil to β-sheet structure with NBG added into it. Porous composite scaffolds had higher compressive strength and compressive modulus compared to pure SF porous scaffold. The bioactivity in vitro of composite scaffolds were studied through immersing it into simulated body fluid, the samples were also characterized by XRD, FTIR and FESEM. The results indicated that hydroxyapatite(HA) layers were formed on the porous composite scaffolds after immersed in SBF for seven days, the speed of HA deposition was accelerated with NBG adding into SF. The result was that SF/NBG porous composite scaffolds were expected to be as good bioactivity materials for bone tissue repairing.

Select

Research on preparation and lamination of cordierite green tapes

WANG Shao-hong;ZHOU Dan;HOU Zhao-xia;WANG Mei-han;HU Xiao-dan;NIU Chang-lei

. 2013, 44(02): 232-235.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Water based tape casting slurry of cordierite with good performances of fluidity and stability was acquired via the research of slurry system. The tapes prepared by the slurry could be sintered at low temperature. Moreover, the compactness is better, the relative density is higher and the dielectric properties are good. Lamination of green tapes was studied mostly. The results showed that the tapes could be laminated well at ambient temperature. Five green tapes could be bonded well at 2.5MPa. However, pores would appear when the layers increased to 10 and the sintering properties would become worse. The sintering properties could be improved with increasing pressure. Compared with thermo-pressure lamination, the pressure and temperature during lamination are lower; with solvent or gluing based lamination, additional additives are not needed.

Select

Bi-stable Characteristics of Orthogonal Unsymmetric Carbon-fiber Composite Structure

ZHANG Zheng;WU He-long;WU Hua-ping;BAO Yu-mei;CHAI Guo-zhong

. 2013, 44(02): 236-239.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The bi-stable characteristics of [0o/90o] layup orthogonal unsymmetric carbon-fiber composite structure for different geometrical size are studied in this paper. Based on the analysis of the bi-stable mechanism and theoretical method of this kind unsymmetric composite，the carbon-fiber/epoxy resin(T700/3234) specimens which own bi-stable properties were fabricated successfully. The total snap processes including curing and cooling to first stable state, snapped from one stable shape to another and back to the first stable is given. The variation law of the coiled-up radius, out-of-plane displacement, maximum snap-through and snap-back loads, and load-displacement curvatures is analyzed finally.

Select

Preparation and photocatalytic degradation properties on dyes of TiO2 nanofibers

GAO Chun-tao;CAI Yi-bing;WANG Qing-qing;WEI Qu-fu;XU Yang

. 2013, 44(02): 240-243.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Combined with sol-gel technique and electrospinning methods, the electrospun precursor solution was prepared through mixing the PVP and tetrabutyl titanate; and then PVP/TiO2 composite nanofibers were prepared by electrospinning. The TiO2 nanofibers as photo catalysis were prepared by calcinating PVP/TiO2 composite nanofibers at 500oC. The photocatalytic degradation properties of TiO2 nanofibers were studied through taking different kinds of dyes (Cationic Brilliant Red 5GN, Weak Acid Yellow GN、Remazol Blue RR) as organic pollutant model. The structural morphology of the PVP/TiO2 andTiO2 nanofibers was characterized by SEM. The composition and crystal structure of TiO2 nanofibers were analyzed by FT-IR spectra and XRD. The experimental results indicated that TiO2 nanofibers processed desired morphology, anatase-TiO2 crystal structure and good photocatalytic degradation properties on different dyes.

Select

The effect of Cu content on the properties and electrochemical behavior of electroless Ni-Cu-P coatings

XU Yang;ZOU Yong;LUAN Tao

. 2013, 44(02): 244-248.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Ni-Cu-P coatings with different Cu content were prepared by changing the concentrations of Cu ions and additives in the plating baths. SEM, XRD, DSC and electrochemical tests were employed to investigate the relationship between Cu content and the properties of the coatings. It’s indicated that the increase of Cu content promotes the deposited particles fine and the coating structure dense. The introduction of Cu to the coating decreases the P content and increases the ordered degree of the coating. Polarization curves of the coatings showed that the coatings with higher Cu content exhibited higher corrosion resistance with lower porosity, higher corrosion potential and lower corrosion current density. The results of EIS tests confirmed this result and revealed that the corrosion behavior changed along with the increase of the Cu content of the coating.

Select

The Analysis of the Fractions of WPCB vacuum pyrolysis oil

YANG Fan;SUN Shui-yu;LIU Jing-yong;XU Dong-jun;ZHANG Rong-xue;ZHONG Sheng;LI Shen-yong;WU Jia-qi;WANG Yi

. 2013, 44(02): 249-252.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Pyrolysis is known as a promising technique for resoure utilization of WPCB. The pyrolytic oil (PO) should be utilized according to the potential value of recycling. But it has not been applied in large-scale due to its complicated chemical composition. This paper focused on the analysis of the fractions of PO, which the fractions was obtained by the distillation of pyrolytic oil and analysed by elemental analyzer, GC-MS and FTIR. The results showed that all the fractions consisted of over 50% of C and 6% of H. The phenolic compounds, which contains Phenol, 4-(1-methylethyl)-Phenol and 2-(1-methylethyl)-Phenol, accounting for 60% of pyrolytic oil. The spectrogram of the fractions of PO appeared characteristic peak such as CH2, CH-OH. Besides, less than 10% of Br, which existed in bromophenolic compounds, was analysed in the pyrolytic oil. This works could provide theoretical basis for further research on the utilizing of all the components from pyrolysis of WPCB.

Select

Effect of Interface control on Properties of Bamboo fibers/polylactic acid Composites

LI Xin-gong;ZHENG Xia;WU Yi-qiang

. 2013, 44(02): 253-257.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The interface of the bamboo fibers（BF）/ polylactic acid(PLA) was controlled by alkali（NaOH）treatment, isocyanate (MDI) treatment and alkali + isocyanate treatment, respectively. The results show that all of the three kinds of the interface control methods could improve the adhesion properties, tensile strenth, impact strength，and water resistance of BF / PLA composites were improved. After interface control, activation energy for flow of composites was increased, but thermal flow became somewhat difficult due to crosslinking between PLA and BF; glass transition temperature and crystallization temperature of composites were increased, and melting peak became narrow; thermal degradation temperature and heat stability of composites were increasee. NaOH + MDI combined treatment has the best positive interface control effects, and has more significant effect on properties of composites.

Select

Experimental study on mechanical behavior of superelastic shape memory alloy bar

Ren Wen-jie;WANG Li-qiang;JIA jun-sen;JIA Ru

. 2013, 44(02): 258-261.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Experiments on the mechanical behavior of the superelastic SMA bar are performed. Cyclic number, strain amplitude and loading frequency are considered to investigate their effects on the hysteretic curve and the mechanical parameters, such as energy dissipation per cycle, loss factor and residual strain. The results show that the stress-strain curve changes gradually to reach an approximately steady state with the increasing number of loading cycles. As strain amplitude increases, the energy dissipation and the loss factor increase. As loading frequency increases, the energy dissipation and the loss factor decrease. The steady superelastic SMA bar has the poor capabilities of superelasticity, energy dissipation and damping property, so the material can be used as recentering devices or restrainers in the civil engineering.

Select

Effect of Isotope on Irradiation Damage in Pure Iron

JIANG Shao-ning;WAN Fa-rong;LONG Yi;HE Jian-chao;WANG Shuai;OHNUKI Somei

. 2013, 44(02): 262-265.

Abstract ( )

Download PDF ( )

Knowledge map

Save

There are systematic works on the interaction between helium and irradiation defects, while not so many on hydrogen. Especially, the isotopic atoms of hydrogen, deuterium or tritium would exist in the environment of fusion reaction. However, few works were reported about the isotope effect of hydrogen on irradiation damage. This work used ion accelerator to implant ions of deuterium into the samples of pure iron at R.T., followed by annealing at high temperature to make the defects develop into large dislocation loops. The electron irradiation by high voltage electron microscope was carried out to check the nature of loops. The isotopic effect on the bias of dislocation loops was discussed.

Select

The effects of synthesis conditions on the morphology and optical properties of porous VO2 films

XU Yuan-jie;HUANG Wan-xia;SHI Qi-wu;ZHANG Yang;SONG Lin-wei

. 2013, 44(02): 266-269.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Abstract: Porous vanadium dioxide films have been fabricated in different conditions on muscovite (001) substrates with the addition of surfactant Cetyltrimethyl Ammonium Bromide (CTAB) by sol-gel method. SEM and FT-IR are used to investigate the morphology and therchromic properties of the VO2 films. The results reveal that annealing technical parameters have great effect on morphology, grain size and optical properties of porous VO2 films, and the synthesis of porous VO2 films is depend on annealing temperature, holding time and annealing atmosphere.

Select

High resolution transmission electron microscope and crystallization kinetics study of nanocrystallization of α-Fe in Fe83Zr7B9Mn1 amorphous alloy

HOU Kai;HUANG Qin;BI Xiao-fang

. 2013, 44(02): 270-274.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Crystallization process and non-isothermal crystallization kinetics of α-Fe nanophase for the annealed Fe83Zr7B9Mn1 amorphous alloy have been studied via high-resolution transmission electron microscopy (HRTEM) observation combined with differential scanning calorimetry (DSC) analysis. The α-Fe phase precipitated from Fe83Zr7B9Mn1 amorphous matrix is confirmed by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). For the alloy annealed at 903 K, the average size of α-Fe nanocrystals reaches over 20 nm. Based on Flynn-Wall-Ozawa method, exothermic peaks in the DSC are resolved and apparent activation energy is estimated to be Ea=260.3kJ/mol. It is further verified that the non-isothermal nanocrystallization process of α-Fe in Fe83Zr7B9Mn1 follows Sesták -Berggren autocatalytic model rather than JMA model, which gives the pre-exponential factor conversion function.

Select

Alkali and thermal treatment of titanium and its effect on the bioactivity

WANG Xiao-Hong;CAO Yang;ZHANG Li;CAO Xian-ying;JIN Chun-yang;CAO Feng

. 2013, 44(02): 275-280.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The dioxide thin films with different morphologies and different crystalline on the surface of titanium was prepared by NaOH solution. Part of the samples were annealed at 450°C and 700°C. Experimental results showed that the unannealed samples treated by alkali were mainly amorphous gel layer of titanium, annealed samples at 450°C were anatase-TiO2, annealed samples at 700°C were rutile-TiO2. The annealed samples at 700°C were good biological activity for the surface of 50nm-nanoparticles, which was favorable to hydroxyapatite formation, cell adhesion and proliferation for the nano-size effect. Annealed samples at 450°C induced the rapider growth of hydroxyapatite than the not annealing samples for the anatase-TiO2. Namely, anatase-TiO2 is better to induce the hydroxyapatite deposition than the amorphous gel of titanium. Unannealed samples were better to induce the hydroxyapatite deposition than the titanium only polished with emery paper because of the rough morphology and the emergence of hydroxyl group (–OH).

Select

Study on quantum transport properties of graphene Dirac fermions

YANG Jun;JIANG Kai-ming;WU Wen-yuan;CHEN Lei;REN Xing-hai

. 2013, 44(02): 281-284.

Abstract ( )

Download PDF ( )

Knowledge map

Save

We studied the graphene Dirac fermions barrier-dependence transport properties by using tight-binding model method. Taking account of graphene Dirac fermions incident angle, incident energy and the barrier height or barrier thickness, we analyzed the graphene Dirac fermions transmission coefficient of the barrier. Theoretical analysis and numerical calculations show that the tunneling coefficient of Dirac fermions in graphene appears a clear oscillation effect with height and thickness of the square barrier varing, and the dependence of tunneling coefficient and incident angle confirms Klein effects. Dirac fermions barrier transmission rate vaies form 0 to 1 with certain parameters as Dirac fermions of the incident energy changes.The change of conductance appears good " conductance switching effect", and this effect will have a good application prospect on microelectronic devices.

Select

Preparation of aqueous PS/PA LIPN chipping-resistant coating for automobile primer

CHEN Peng;WANG Jingyuan;LI Ya-peng

. 2013, 44(02): 285-388.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Aqueous Styrene-acrylic emulsion which formed latex interpenetrating polymer network (LIPN) were successfully synthesized by seed emulsion polymerization technology, and prepared a chipping-resistant coating composition for automobile primer which concluded thickening agent, inorganic fillings and water. The mechanical properties , size distribution of polymer particles, viscosity and thermal property of the emulsion having different mixture ratio were characterized by dynamic mechanical thermal (DMA), universal testing machine, dynamic light scattering-autosizer (DLS), rotary viscometer and thermal gravimetric analyzer（TGA）, respectively, and studied the application performance of the chipping-resistant coating. The results showed that the aqueous Styrene-acrylic emulsion we prepared had good viscosity, polymer particles distributed evenly in the latexes, and the grain size always distributed under 100 nanometers.The film of emulsion we prepared had good damping capacity and heat-stability, using different mixture ratio of monomers had different glass-transition temperatures. The coating we made had good application performance, can be used as chipping-resistant coating composition for automobile primer.

Select

Synthesis and Characterization of the PTMG Aliphatic Hyperbranched Polyurethane

;Longfang Ren;;

. 2013, 44(02): 289-293.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The isocyanate-terminated polyurethane prepolymer (PPU) was synthesized by step-growth polymerization using polytetramethylene ether glycol (PTMG, Mw=2000) with isophorone disocyanate (IPDI) as the monomers, dibutyltin dilaurate (DBTDL) as the catalyst. The appropriate reaction conditions were optimized by single factor experiments as follows. The reaction temperature was 75℃, the reaction time was 1.5h and the quantity of catalyst was equal to 0.007% of feedstocks. And then the hyperbranched polyurethane (HBPU) was synthesized by graft copolymerization using isocyanate-terminated polyurethane prepolymer (PPU) and hyperbranched poly (amide-ester) polyol (HPAE) as the raw materials. The appropriate reaction conditions were optimized by single factor experiments as follows. The reaction temperature was 75℃, the reaction time was 4.5h. The molecular structure of the monomers of PPU and HBPU were characterized by FTIR. The thermal stability of PPU and HBPU were characterized by thermogravimetry.

Select

Catalytic Oxidation of Acid Orange based on the Activation of Hydrogen Peroxide by Silk Fibers Supported Mentallophthalocyanine

ZHENG Bin-bin;HUANG Zhen-fu;ZHUN Shun;YAO Yu-yuan;LV Wang-yang;CHEN Wen-xing

. 2013, 44(02): 294-298.

Abstract ( )

Download PDF ( )

Knowledge map

Save

Cobalt tetrasulfophthalocyanine (CoPcS) was synthesized, characterized by Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectra (TOF-MS), Fourier Transform Infrared Spectra(FT-IR)and Ultraviolet and Visible Spectra (UV-Vis). CoPcS modified by cyanuric chloride was supported onto silk fibers(SF) to obtain a novel supported catalyst (CoPcS-SF). The catalytic oxidation activity for Acid Orange Ⅱ (AO2) was investigated in the presence of H2O2. The experimental results showed that AO2 could be efficiently decomposed in CoPcS-SF and H2O2, and more than 97% of AO2 in 60 min was eliminated at initial pH 7. Moreover, CoPcS-SF could be recycled. The effects of pH, the electrolyte of NaCl and temperature indicated the reaction could efficiently proceed in a wide pH range from 3 to 9, and the reaction rate could be obviously enhanced when NaCl was present, increasing with the elevation of the temperature. FT-IR and Gas Chromatography/Mass Spectrometry (GC-MS) analysis showed that AO2 was mainly oxidized into some small molecular biodegradable aliphatic carboxylic compounds such as maleic acid, fumaric acid, succinic acid, etc.

Select

Characterization of Ammoniation Modified AN-IA Copolymer and its Effect on the Preparation of Carbon Fiber

YU Kuan;ZHU Bo;WANG Qiang;LIU Huan-zhang;WU Yi-mim;ZHANG Shi-lei

. 2013, 44(02): 299-302.

Abstract ( )

Download PDF ( )

Knowledge map

Save

The AN-IA copolymer was modified by ammoniation and the structure of AN-IA copolymer after modification was characterized, the effect of ammoniation modification on the final performance of carbon fiber was studied. The results showed the infrared spectrum was changed with the ratio of IA increasing in some way, the moderate broad peaks appeared at 1730cm-1 and 1700cm-1 and the intensity of peaks increased. The oxygen content of preoxided fiber which prepared by ammoniation modified AN-IA copolymer was over 11%, the pre-oxidization ability significantly improved, and the intensity of carbon fiber after final carbonization can reach 3.76GPa.

Please choose a citation manager

Content to export

30 January 2013, Volume 44 Issue 02