CAJ | 학술논문

分别以高纯碳纳米管( MWCNTs)、未纯化MWCNTs和盐酸纯化MWCNTs为原料,铅( Pb)和石墨( Gr)为压力传递媒介,在4 GPa和7.7 GPa高压和室温条件下制备块体碳纳米管。其直径约为6 nm,呈圆柱形块体。采用拉曼光谱仪、X-射线衍射仪、氮吸附仪和透射电镜表征样品。结果表明,含有MgO催化剂杂质的未纯化MWCNTs,以Pb为媒介时,在7.7 GPa下可获得最佳压缩样品。高压可引起MWCNTs压缩和剪切应力。 Pb容器作为准静压传递媒介可提供更多压缩应力,同时杂质能作为黏结剂,从而有利于得到致密化度较高的MWCNTs。
분별이고순탄납미관( MWCNTs)、미순화MWCNTs화염산순화MWCNTs위원료,연( Pb)화석묵( Gr)위압력전체매개,재4 GPa화7.7 GPa고압화실온조건하제비괴체탄납미관。기직경약위6 nm,정원주형괴체。채용랍만광보의、X-사선연사의、담흡부의화투사전경표정양품。결과표명,함유MgO최화제잡질적미순화MWCNTs,이Pb위매개시,재7.7 GPa하가획득최가압축양품。고압가인기MWCNTs압축화전절응력。 Pb용기작위준정압전체매개가제공경다압축응력,동시잡질능작위점결제,종이유리우득도치밀화도교고적MWCNTs。
High-pressure compaction was used to produce monolithic multiwall carbon nanotubes ( MWCNTs ) from different sources:(1) high-purity commercial Baytubes? , (2) chemical-vapor deposited MWCNTs without purification at the Laboratory of Production of CNT/UNIFRA, and (3) the same MWCNTs as (2) purified with HCl. Pressures of 4. 0 GPa and 7. 7 GPa were ap-plied at room temperature using two different pressure-transmitting media, lead and graphite. Cylindrical monolithic MWCNTs with diameters of about 6 mm were obtained. The samples were characterized by Raman spectroscopy, X-ray diffraction, elemental anal-ysis, N2 adsorption and transmission electron microscopy. Results showed that the best sample was obtained with MWCNTs without purification, containing residues of MgO catalyst, and using lead as the pressure-transmitting medium at 7. 7 GPa. High-pressure may cause compressive stress and shear stress for the MWCNTs. The lead container, as a quasi-hydrostatic pressure-transmitting medium, provided more compressive stress than shear stress while the impurities acted as binding materials. Both helped to obtain better densification of the MWCNTs.