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Influences of Polypropylene Fiber and SBR Polymer Latex on Abrasion Resistance of Cement Mortar

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Journal of Wuhan University of Technology(materials Science) 2010年第4期25卷 624-627页

作者：徐方 key laboratory of Silicate {2. Science and Engineering of ministry of education Wuhan University of Technology

Influences of polypropylene （PP） fiber and styrene-butadiene rubber （SBR） polymer latex on the strength performance, abrasion resistance of cement mortar were studied. The experimental results show that the flexural strength, brittleness index （σF/σC） and abrasion resistance can be improved significantly by the addition of PP fiber and SBR polymer latex. The relationship between the flexural strength and abrasion resistance was analyzed, showing a good linear relationship between them. The reinforced mechanism of PP fiber and SBR polymer latex on cement mortar was analyzed by some microscopic tests. The test results show that the addition of SBR polymer latex has no significant influence on the cement hydration after 7 d curing. Adding SBR polymer latex into cement mortar can form a polymer transition layer in the interfaces of PP fiber and cement hydrates, which improves the bonding properties between the PP fiber and cement mortar matrix effectively.

关键词： polypropylene fiber SBR polymer latex cement mortar brittleness index abrasion resistance

Polyurethane Grafted Attapulgite as Novel Fillers for Nylon 6 Nanocomposites

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Journal of Wuhan University of Technology(materials Science) 2011年第4期26卷 615-619页

作者：史建设杨绪杰 key laboratory for Soft Chemistry and Functional {2. of the ministry education Nanjing University of Science and Technology

Attapulgite fibers were modified by polyurethane, forming polyurethane grafted attapulgite （AT-PU）, which was confirmed by Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS）. Nylon 6/AT-PU nanocomposites of different modified attapulgite loadings were prepared by melt blending in a twin screw extruder. Scanning electron microscopy （SEM） observation on the fracture surfaces of the nanocomposites showed not only a uniform dispersion of AT-PU but also a strong interfacial adhesion with the matrix. Differential scanning calorimeter （DSC） and Thermogravimetric analyzer （TGA） were used to illustrate the infiuence of AT-PU particles on the thermal properties of the nylon 6/AT-PU nanocomposites. The results indicated that the addition of attapulgite probably induced the heterogeneous nucleation and was favorable for the formation of γ -crystalline form, and that the higher thermal stability was obtained for the composites.

关键词： polyurethane grafted attapulgite nylon 6 nanocomposites

Preparation, Properties and Characterization of Modified CeO_2.La_2.r_2._7 Buffer Layers

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稀有金属材料与工程 2011年第S3期40卷 350-353页

作者： Cheng Yanling, Suo Hongli, Liu Min, Ma Lin, Zhang Teng key laboratory of Advanced Functional {2.s, ministry of education, Beijing University of Technology, Beijing 10012., china Beijing Univ Technol Coll Mat Sci & Engn Minist Educ Key Lab Adv Funct Mat Beijing 100124 Peoples R China

The metal organic deposition (MOD) method was used for the epitaxial growth of the CeO2.La2.r2.7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer. The material phase and the macro-orientations were analyzed by XRD. The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES. The grain orientation and the crystallographic growth mode of the CeO2.layer were first characterized by electron backscattering diffraction (EBSD). The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2.LZO buffer layers, and the CeO2.LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier. The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample, the percentage of {001} rotated cube texture of CeO2.layer reaching 97.4% at the accelerating voltage of 15 kV, thus showing epitaxial deposition with a high texture.

关键词： coated conductor buffer layer La2.r2.7 seed layer CeO2 rotated cube texture accelerating voltage

Atom Transfer Radical Polymerization of Methyl Methacrylate in [Hmim][HCOO]/THF Mixtures

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Journal of Wuhan University of Technology(materials Science) 2010年第5期25卷 785-788页

作者：胡自强来国桥 key laboratory of Organosilicon Chemistry and {2. Technology of ministry of education Hangzhou Normal University

The atom transfer radical polymerization （ATRP） of methyl methacrylate （MMA） employing ethyl 2.bromoisobutyrate （EBiB）/CuBr as the initiating system was analyzed at 30, 40, 50 and 60 ℃ in N-methylimidazolium formate （[Hmim][HCOO]）/THF mixtures. The polymerization was performed in a well-controlled manner as evidenced by kinetic study and the chain extension result. The apparent activation energy and the enthalpy of equilibrium for the preequilibrium were also investigated. Results show that Ea（app）=47.86 kJ/mol, △Heq^0=2..67 kJ/mol.

关键词： ATRP methyl methacrylate ionic liquids activation energy

Improved electrochemical performances of polyaniline nanotubes-poly-L-lysine composite for label-free impedance detection of DNA hybridization

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Science china Chemistry 2010年第6期53卷 1371-1377页

作者： YANG Tao,JIANG Chen,ZHANG Wei & JIAO Kui key laboratory of Eco-chemical Engineering,{2. of education College of Chemistry and Molecular Engineering,Qingdao University of Science and Technology,Qingdao 2.6042.china key laboratory of Eco-chemical Engineering Ministry of Education College of Chemistry and Molecular Engineering Qingdao University of Science and Technology Qingdao China

A sensitive label-free DNA hybridization biosensing platform was fabricated based on the synergistic effect of polyaniline nanotubes (PANInt) and poly-L-lysine (pLys).The composite of pLys and PANInt was coated onto the carbon paste electrode (CPE) to form a uniform and very stable nanocomposite *** pLys in the composite film not only acts as a membrane to retain good electron transfer capability of PANInt even at physiological pH,but also possesses fine biocompatibility for *** probes with negatively charged phosphate groups were readily linked to the positively charged pLys surface due to the strong electrostatic *** synergistic effect of PANInt and pLys could significantly enhance the sensitivity of DNA hybridization *** phosphinothricin acetyltransferase (PAT) gene fragment from transgenic corn and the polymerase chain reaction amplification of the terminator of nopaline synthase gene from the real sample of a kind of transgenic soybean were detected by this DNA electrochemical biosensor via label-free impedance *** stable composite gives convenient permselectivity properties as a transducer material for the design of modern electrochemical impedance biosensor using [Fe(CN)6]3-/4as an indicator.

关键词： poly-L-lysine polyaniline nanotubes DNA electrochemical biosensor PAT gene NOS gene

Preparation of nanocrystalline BaTiO_3 ceramics

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Science china(Technological Sciences) 2009年第6期52卷 1730-1734页

作者： DENG XiangYun1,2.LI DeJun1,LI JianBao2.WANG XiaoHui3 & LI LongTu3 1 College of Physics and Electronic Information,Tianjin Normal University,Tianjin 300387,china 2.materials and Chemical Engineering Institute,{2. laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering material of ministry of education,Hainan Provincial {2. laboratory of Research on Utilization of Si-Zr-Ti,Hainan University,Haikou 5702.8,china 3 Department of materials Science and Engineering,Tsinghua University,Beijing 100084,china College of Physics and Electronic Information Tianjin Normal University Tianjin China materials and Chemical Engineering Institute Key Laboratory for Hainan Advantage Resources and Applied Technology in Chemical Engineering Material of Ministry of Education Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Hainan University Haikou China Department of materials Science and Engineering Tsinghua University Beijing China

The high-dense nanocrystalline BaTiO3(BT)ceramics with grain size smaller than 100nm have been successfully prepared by the two step sintering and the spark plasma sintering(SPS)*** successive transitions in nanograin BT ceramics from rhombohedral to orthorhombic,tetragonal and cubic transitions,similar to those in coarse BT ceramics,were revealed by in-situ temperature dependent Raman *** multiphase coexistence and the diffused phase transition character were demonstrated in the 8nm nanocrystalline BT ceramics.

关键词： nanocrystalline BaTiO3 ceramics preparation microstructure size effect

Performance characterization of rigid polyurethane foam with refined alkali lignin and modified alkali lignin

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Journal of Forestry Research 2009年第2期20卷 161-164页

作者： LIU Zhi-ming, YU Fei, FANG Gui-zhen, YANG Hui-jun key laboratory of Bio-based {2. Science and Technology, ministry of education, Northeast Forestry University, Harbin 150040, P.R.china key laboratory of Bio-based {2. Science and Technology Ministry of Education Northeast Forestry University Harbin P.R. China

The two kinds of rigid polyurethane(PU) foams were prepared with respectively adding the refined alkali lignin and alkali lignin modified by 3-chloro-1,2.epoxypropane to be instead of 15% of the polyether glycol in *** indexes of mechanical performance, apparent density, thermal stability and aging resistance were separately tested for the prepared PU *** results show that the mechanical property, thermal insulation and thermal stability for PU foam with modified alkali lignin are excellent among two kinds of PU foams and control *** additions of the refined alkali lignin and modified alkali lignin to PU foam have little effect on the natural aging or heat aging resistance except for decreasing hot alkali resistance ***, the thermal conductivity of modified alkali lignin PU foam is lowest among two kinds of PU foams and control *** alkali lignin PU foam modified by 3-chloro-1,2.epoxypropane could be applied in the heat preservation field.

关键词： refined alkali lignin modified alkali lignin rigid PU foam mechanic performance thermal stability

Factors impacting nanoindentation testing results of the cuticle of dung beetle Copris ochus Motschulsky

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Journal of Bionic Engineering 2004年第4期1卷 221-230页

作者： TONG Jin , SUN Ji-yu , CHEN Dong-hui , ZHANG Shu-jun 1 1 1 2.1. key laboratory for Terrain-Machine Bionics Engineering ({2. of education, china), Jilin University, 5988 Renmin Street, Changchun 13002., P. R. china 2. Department of Multi-media and Computing, University of Gloucestershire, Cheltenham, The Park, GL50 2.F, UK. 1 key laboratory for Terrain-Machine Bionics Engineering({2. of education China) Jilin University 5988 Renmin Street Changchun 130022 P. R. China Department of Multi-media and Computing University of Gloucestershire Cheltenham The Park GL50 2QF UK.

The cuticle of dung beetle is a layered composite material in micro- or nano-scale. Dung beetle can fly, walk and dig. It can shovel and compact dung of mammals into balls. It use foreleg to walk, midleg and hindleg to hold and impel dung ball. Its two foreleges as digging legs are developed. The factors impacting the nanoindentation testing results of the femur cuticle of forelegs of dung beetle Copris ochus Motschulsky were examined. The nanomechanical test instrument used for the tests was Hysitron nanomechanical system. The results shown that the holding time and loading time are important factors im- pacting the accuracy of such indentation properties as reduced modulus (Er) and the harness ( H ) of the femur cuticle of the forelegs of dung beetle Copris ochus Motschulsky in nanoscale. There exists a threshold holding time of 2. s for the reduced modulus of the femur cuticle. The tests of nanoindentation creep property and the regression analysis of relationship between the depth increment at the maximum load and the time further confirmed the correction of the above threshold holding time. There exist visco-elastic-plastic behaviour and creep phenomenon in the femur cuticle during indenting. Its creep property during the holding procedure at maximum load can be regressed by a general logarithmic equation. The equation fitted by the testing data is ? h = 54.83452.ln(0.0072.t +1.00486), where, ? h is the depth increment at the maximum load and t is the time.

关键词： insect dung beetle cuticle nanoindentation holding time loading time creep 1

Preparation of Li_4Ti_5O_(12. submicrospheres and their application as anode materials of rechargeable lithium-ion batteries

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Science china Chemistry 2011年第6期54卷 936-940页

作者： ZHANG Ai, ZHENG ZongMin, CHENG FangYi, TAO ZhanLiang & CHEN Jun key laboratory of Advanced Energy {2.s Chemistry, ministry of education College of Chemistry, Nankai University, Tianjin 300071, china key laboratory of Advanced Energy {2.s Chemistry Ministry of Education College of Chemistry Nankai University Tianjin China

We report on the preparation of spinel Li4Ti5O12.submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12.submicrospheres are synthesized with three steps of the hydrolysis of TiCl4 to form rutile TiO2. the hydrothermal treatment of rutile TiO2.with LiOH to prepare an intermediate phase of LiTi2.4+δ, and the calcinations of LiTi2.4+δ to obtain spinel Li4Ti5O12. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters of Li4Ti5O12.submicrospheres with novel hierarchical microstructures are about 2.0–300 nm with the assembly of 2.–30 nm nanoparticles. The electrochemical properties of Li4Ti5O12.submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li4Ti5O12.display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li4Ti5O12.is calculated to be 1.03 × 10-7 cm2.s. The present results indicate that the as-prepared Li4Ti5O12.submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications.

关键词： Li4Ti5O12 TiO2 TiCl4 anode material lithium-ion battery