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Mechanical and microstructural characterization of Al7075/SiC nanocomposites fabricated by dynamic compaction

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International Journal of Minerals,Metallurgy and Materials 2014年第3期21卷 295-303页

作者： A.Atrian G.H.Majzoobi M.H.Enayati H.Bakhtiari Mechanical Engineering Department Bu-Ali Sina University Department of Materials Engineering Isfahan University of Technology

This paper describes the synthesis of Al7075 metal matrix composites reinforced with SiC, and the characterization of their microstructure and mechanical behavior. The mechanically milled Al7075 micron-sized powder and SiC nanoparticles are dynamically compacted using a drop hammer device. This compaction is performed at different temperatures and for various volume fractions of SiC nanoparticles. The relative density is directly related to the compaction temperature rise and indirectly related to the content of SiC nanoparticle reinforcement, respectively. Furthermore, increasing the amount of SiC nanoparticles improves the strength, stiffness, and hardness of the compacted specimens. The increase in hardness and strength may be attributed to the inherent hardness of the nanoparticles, and other phenomena such as thermal mismatch and crack shielding. Nevertheless, clustering of the nanoparticles at aluminum particle boundaries make these regions become a source of concentrated stress, which reduces the load carrying capacity of the compacted nanocomposite.

关键词： nanocomposites metallic matrix composites silicon carbide nanoparticles compaction

POLYMER-CLAY nanocomposites:CHEMICAL GRAFTING OF POLYSTYRENE ONTO CLOISITE 20A

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Chinese Journal of Polymer Science 2012年第6期30卷 815-823页

作者： Yagoub Mansoori Khadijeh Roojaei Mohammad RezaZamanloo Gholamhassan Imanzadeh Department of Applied Chemistry Faculty of ScienceUniversity of Mohaghegh ArdabiliArdabil 56199-11367Iran

An account of the experiments on preparing polystyrene （PS） nanocomposites through grafting the polymer onto organophilic montmorillonite is reported. Cloisite 20A was reacted with vinyltrichlorosilane to replace the edge hydroxyl groups of the clay with a vinyl moiety. Because the reaction may liberate HC1, it was performed in the presence of sodium hydrogencarbonate to prevent the exchange of quaternary alkylammonium cations withH＋ ions. Only the silanol groups on the edge of the clay react with vinyltrichlorosilane. The radical polymerization of the product with styrene as a vinyl monomer leads to chemical grafting of PS onto the montmorillonite surface. The homopolymer formed during polymerization was separated from the grafted organoclay by Soxhlet extraction. Chemical grafting of the polymer onto Cloisite 20A was confirmed by infrared spectroscopy. The prepared nanocomposite materials and the grafted nano-particles were studied by XRD. Exfoliated nanocomposites may be obtained for 0.5 wt%-1wt% clay content. The nanocomposites were studied by thermogravimertic analysis （TGA） dynamic thermal analysis （DTA） and dynamic mechanical analysis （DMTA）.

关键词： Grafting Polystyrene nanocomposites Cloisite 20A Organophilic clay.

SYNTHESIS OF EXFOLIATED ISOTACTIC POLYPROPYLENE/FUNCTIONAL ALKYL-TRIPHENYLPHOSPHONIUM-MODIFIED CLAY nanocomposites BY IN SITU POLYMERIZATION

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Chinese Journal of Polymer Science 2013年第11期31卷 1501-1508页

作者： Kai Du 贺爱华 Fu-yong Bi Charles C.Han Fine Chemicals Department Beijing Research Institute of Chemical IndustrySINOPEC State Key Laboratory of Polymer Physics and Chemistry Joint Laboratory of Polymer Science and MaterialsBeijing National Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsSchool of Polymer Science and EngineeringQingdao University of Science and Technology State Key Laboratory of Polymer Physics and Chemistry Joint Laboratory of Polymer Science and MaterialsBeijingNational Laboratory for Molecular ScienceInstitute of ChemistryChinese Academy of Sciences

Diphenyl （4-hydroxyphenyl） hexadecyl phosphonium bromide （POH） -modified montmorillonite （POHMMT） was used to prepare a novel TiC14/MgC12/POHMMT compound catalyst and exfoliated iPP/POHMMT nanocomposites were prepared by the in situ intercalative polymerization of propylene with the TiC14/MgC12/POHMMT compound catalyst. The POH surfactants don＇t change the catalytic characteristic of the Z-N catalyst and the obtained PP presents high isotacticity, normal molecular weight and molecular weight distribution. The WAXD, SAXS and TEM results demonstrate the highly exfoliated iPP/POHMMT nanocomposites were produced by the in situ polymerization with this novel catalyst, while the intercalated iPP/Na＋MMT nanocomposites were produced with the TiC14/MgC12/Na＋MMT compound catalyst. Through this approach, in situ propylene polymerization can actually take place between the silicate layers and lead not only to PP with high isotacticity and molecular weight, but also to highly exfoliated PP nanocomposites.

关键词： Clay nanocomposites Poly(propylene) (PP) Ziegler-Natta polymerization.

Oligoaniline Assisted Dispersion of Carbon Nanotubes in Epoxy Matrixfor Achieving the nanocomposites with Enhanced Mechanical, Thermaland Tribological Properties

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Chinese Journal of Polymer Science 2017年第3期35卷 446-454页

作者： Bin Chen Jia Chen Jing-yu Li Xin Tong 赵海超王立平 School of Materials Science and Engineering Shenyang University of Chemical Technology Shenyang 11 O142 China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials andProtective Technologies Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China

A critical challenge for initiating many applications of the carbon nanotubes(CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes(CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer(AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.

关键词： Carbon nanotubes Epoxy Mechanical Tribological nanocomposites

Preparation and property of CL-20/BAMO-THF energetic nanocomposites

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Defence Technology（防务技术） 2019年第3期15卷 306-312页

作者： Teng Chen Yan Zhang Shuang-feng Guo Liu-ming Zhao Wei Chen Ga-zi Hao Lei Xiao Xiang Ke Wei Jiang National Special Superfine Powder Engineering Research Center of China School of Chemical Engineering Nanjing University of Science and Technology Nanjing 210094 PR China Xi'an Modern Chemistry Research Institute Shaanxi 710065 PR China

A sol-gel freezing-drying method was utilized to prepare energetic nanocomposites based on 2, 4, 6, 8,10, 12-hexanitro-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane(CL-20) with 3, 3-Bis(azidomethyl) oxetanetetrahydrofuran copolymer(BAMO-THF) as energetic gel matrix. Scanning electron microscopy(SEM),X-ray diffraction(XRD), Raman, Fourier-transform infrared spectroscopy(FT-IR) and differential thermal analyser(DTA) were utilized to characterize the structure and property of the resultant energetic nanocomposites. Compared with raw CL-20, the average particle sizes of CL-20 in CL-20/BAMO-THF energetic nanocomposites were decreased to nano scale and the morphologies of CL-20 were also changed from prismatic to spherical. FT-IR detection revealed that CL-20 particles were recrystallized in BAMO-THF gel matrix during the freezing-drying process. The thermal decomposition behaviors of the energetic nanocomposites were investigated as well. The thermolysis process of CL-20/BAMO-THF nanocomposites was enhanced and the activation energy was lower compared with that of raw CL-20,indicating that CL-20/BAMO-THF nanocomposites showed high thermolysis activity. The impact sensitivity tests indicated that CL-20/BAMO-THF energetic nanocomposites presented low sensitivity performance.

关键词： CL-20/BAMO-THF nanocomposites Kinetic Thermodynamic Impact sensitivity

STRUCTURE AND PROPERTIES OF ISOBUTYLENE-ISOPRENE RUBBER/SWOLLEN ORGANOCLAY nanocomposites PREPARED BY SHEAR MIXING

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Chinese Journal of Polymer Science 2011年第2期29卷 225-231页

作者：梁玉蓉张立群 The Institute of Materials Engineering Taiyuan Institute of Technology Key Lab for Nanomaterials Ministry of EducationBeijing University of Chemical Technology

A new approach was developed to prepare high-performance isobutylene-isoprene rubber/swollen organoclay nanocomposites by shear *** with traditional melt compounding method,better dispersion of nanoclay layers in rubber matrix was verified through transmission electron microscopy（TEM） and X-ray diffraction（XRD）.The nanocomposites also exhibit significantly improved mechanical properties and gas barrier *** a mechanism,the molecules of organic swelling agent play a vital role in accelerating the diffusion and intercalation of the matrix molecules.

关键词： Isobutylene-Isoprene rubber Clay nanocomposites Shear mixing

Facile sonochemical synthesis and photocatalysis of Ag nanoparticle/ZnWO4-nanorod nanocomposites

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Rare Metals 2019年第7期38卷 601-608页

作者： Phattranit Dumrongrojthanath Anukorn Phuruangrat Somchai Thongtem Titipun Thongtem Department of Chemistry Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand Department of Materials Science and Technology Faculty of Science Prince of Songkla University Hat Yai Songkhla 90112 Thailand Department of Physics and Materials Science Faculty of Science Chiang Mai University. Chiang Mai 50200Thailand Materials Science Research Center Faculty of Science Chiang Mai University Chiang Mai 50200 Thailand

A facile sonochemical method was developed to synthesize metallic Ag spherical nanoparticles on the surface of ZnWO4 nanorods by forming heterostructure Ag/ZnWO4 *** Ag/ZnWO4 nanocomposites were characterized by X-ray powder diffraction (XRD),Fourier transform infrared spectroscopy (FTIR),field emission scanning electron microscopy (FESEM),transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).The experimental results showed that fcc metallic Ag nanoparticles were supported on surface of monoclinic sanmartinite ZnWO4 *** Ag 3d3/2 and Ag 3d5/2 peaks have well-separated binding energies of 6.00 eV,certifying the existence of metallic *** Ag/ZnWO4 nanocomposites were evaluated for photodegradation of methylene blue (MB) induced by ultraviolet-visible (UV-Vis) *** this research,heterostructure 10 wt% Ag nanoparticle/ZnWO4-nanorod composites have the highest photocatalytic activity of 99% degradation of MB within 60 *** increase in photocatalytic activity was the result of photoinduced electrons in conduction band of ZnWO4 that effectively diffused to metallic Ag spherical nanoparticles and the inhibition of electron-hole recombination process.

关键词： Ag/ZnWO4 nanocomposites Photocatalysis Nanostructure materials Semiconductor

Microstructure evolution of hot-deformed SmCo-based nanocomposites induced by thermo-mechanical processing

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Journal of Materials Science & Technology 2023年第7期138卷 193-202页

作者： Yuan Teng Yuqing Li Xiaochang Xu Ming Yue Weiqiang Liu Dongtao Zhang Hongguo Zhang Qingmei Lu Weixing Xia Faculty of Materials and Manufacturing Key Laboratory of Advanced Functional MaterialsMinistry of Education of ChinaBeijing University of TechnologyBeijing 100124China Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo 315201China

Nanocomposite permanent magnets have ultra-high theoretical magnetic energy products,due to cou-pling of the soft/hard magnetic phases,inciting strict microstructural *** this study,the microstructure evolution,including the phase transition,morphological changes,and texture formation,of hot-deformed SmCo-based nanocomposites under thermal-stress-strain coupling was characterized to determine a possible strategy for achieving high *** SmCo_(5)/α-Fe nanocomposites precursor contained fine and dispersed Sm(Fe,Co)_(5)and Fe-Co grains and exhibited a two-stage phase transforma-tion accompanied by grain *** the early stage of deformation at relatively low temperature,the adjacent Sm(Co,Fe)5 and Fe-Co phase formed the Sm_(2)(Co,Fe)_(17)-H phase,which was stable only with small grain *** the high-temperature deformation stage,the Sm_(2)(Co,Fe)_(17)-H phase transformed into the Sm_(2)(Co,Fe)_(17)-R phase with large grain *** addition,the strong c-axis texture formed in the Sm(Co,Fe)_(5)phase but not in the Sm_(2)(Co,Fe)_(17)-R ***,the phase transition process and texture formation mechanism were systematically analyzed by transmission electron *** ini-tiation of a slip system and/or preferential grain growth explained the formation of texture under the action of uniform stress and strain and assisted by dispersed Sm-rich *** Sm_(2)(Co,Fe)_(17)-R grains with poor orientations and large grain sizes did not achieve magnetic hardening,which also dam-age the magnetic *** to the results of this work,we also presented a new strategy to prepare high-performance SmCo-based nanocomposites magnets.

关键词： nanocomposites Phase transition Microstructure C-axis texture Hot deformation

High-performance supercapacitors based on Ni_(2)P@CNT nanocomposites prepared using an ultrafast microwave approach

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Frontiers of Chemical Science and Engineering 2021年第4期15卷 1021-1032页

作者： Yunrui Tian Haishun Du Shatila Sarwar Wenjie Dong Yayun Zheng Shumin Wang Qingping Guo Jujie Luo Xinyu Zhang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Department of Chemical Engineering Auburn UniversityAuburnAL 36849USA

We present a one-step route for the preparation of nickel phosphide/carbon nanotube(Ni_(2)P@CNT)nanocomposites for supercapacitor applications using a facile,ultrafast(90 s)microwave-based ***2P nanoparticles could grow uniformly on the surface of CNTs under the optimized reaction conditions,namely,a feeding ratio of 30:50:25 for CNT,Ni(NO_(3))_(2)-6H_(2)O,and red phosphorus and a microwave power of 1000 W for 90 *** study demonstrated that the single-step microwave synthesis process for creating metal phosphide nanoparticles was faster and simpler than all the other existing *** results showed that the specific capacitance of the optimal Ni2P@CNT-nanocomposite electrode displayed a high specific capacitance of 854 F•g^(-1) at 1 A•g^(-1) and a superior capacitance retention of 84% after 5000 cycles at 10 Ag^(-1).Finally,an asymmetric supercapacitor was assembled using the nanocomposite with activated carbon as one electrode(Ni_(2)P@CNT//AC),which showed a remarkable energy density of 33.5 W•h•kg^(-1) and a power density of 387.5 W·kg^(-1).This work will pave the way for the microwave synthesis of other transition metal phosphide materials for use in energy storage systems.

关键词： Ni_(2)P CNT supercapacitors nanocomposites microwave