Papers by Keyword: MWNTs

Abstract: Polyacrylonitrile（PAN）/multi-walled carbon nanotubes (MWNTs) composite fibers were prepared by melt spinning using ionic liquids (ILs) as a plasticizer. The effects of different MWNTs contents on the morphology, mechanical and conductive properties of the composite fibers were discussed. The results showed that property improvements have occurred with the adding of MWNTs. When the content of MWNTs reached 10%, the conductivity of PAN/MWNTs was 8.65×10-3 S/cm.

Abstract: Oxidized MWNTs were obtained by the oxidization in the mixture of concentrated HNO3 and H2SO4. Amino-functionalized MWNTs were obtained by the oxidized MWNTs reacting with aliphatic amines. The structure and properties of functionalized MWNTs were characterized by FT-IR, TGA, XRD and nanoparticle size analyzer.

Abstract: The filling of carbon nanotubes with Fe-Mn oxide via wet chemistry was presented. IR, XRD and TEM were used to characterize the structural features and the morphology. Cyclic voltammetry was used to investigate the electrochemical behavior of the samples. Results shows that the Fe2O3 and MnO2 were filled the tube inner cavity successfully and the nanocomposites were valuable for supercapacitor materials.

Abstract: Multi-walled carbon nanotubes (MWNTs) were used as filler to enhance thermal conductivity of Ethylene propylene diene monomer (EPDM) polymers. In order to study the thermal conductivity of the MWNTs/EPDM composites in three different directions, an experiment was conducted by the heat probe method. The results show the general average thermal conductivity of MWNTs/EPDM composites is 0.323 W/m•K，which is significantly higher than EPDM polymers. The maximum difference of thermal conductivity between two directions is 8.7% relative to the general average, indicating obvious anisotropic behavior.

Abstract: This paper discusses the processing of a hybrid of TPNR-MWNTs-OMMT nanocomposites with different percentages of filler to determine the optimum mechanical properties of the hybrid nanocomposites. Three types of hybrid nanocomposites with various MWNTs-OMMT compositions (1%wt MWNTs+3%wt OMMT), (2%wt MWNTs+2%wt OMMT) and (3%wt MWNTs+1%wt OMMT) were prepared. The OMMT layers were found to be separated further with higher nanotubes content as exhibited by X-ray diffraction. The result of tensile test showed that tensile strength and Young's modulus increase in the presence of nanotubes and maximum value were obtained for the nanocomposites with highest nanotubes (3%wt) which increased about 33% and 36%, respectively compared with pure TPNR matrix. On other hand, the elongation at break considerably decreased with increasing the percentage of MWNTs. TEM micrographs revealed aspect ratio and fillers orientation in the TPNR matrix also promoted strongly to interfacial adhesion between fillers and the matrix which contributed significantly to the improvement of the mechanical properties

Abstract: Consecutive PA6/MWNTs nanofiber filaments were successfully fabricated by an improved electrospining method in this paper. The microstructure and the arrangement of MWNTs in the nanofibers both with the conductivities of the filaments in different MWNTs contents were studied. The results show that the orientation arrangement of the nanofiber and MWNTs in the fibers were both fine at different MWNTs contents .Besides, with the increase of the MWNTs contents, the diameters of the nanofiber increased, while the conductivity of the filaments increased and MWNTs became gathered in the fibers.

Abstract: A series of polyimide composites with various mass fractions of multi-walled carbon nanotubes (MWNTs) were prepared by in situ polymerization. MWNTs were treated with an acid mixture and sulfoxide chloride in turn to increase the chemical compatibility of carbon nanotubes with the polyimide matrix. The modified MWNTs are dispersed homogeneously in the matrix while the structure of the PI and MWNTs structures are stable in the preparation process. The composite films hold preferable thermal stability as same as the pure PI. The dielectric constants of the composites decreased with the increasing frequency and increase sharply with the adding of MWNTs.

Abstract: Electrospining technique is one of the hotest topics all over the world. The main form of the electrospun products is generally nonwoven fiber web with the poor mechanical properties. Consecutive PA6/MWNTs nanofiber filaments were successfully fabricated by an improved electrospining method. Peregal O was used as the bath to post-draw the as-spun filaments and the effects of draw ratio on their structures and properties were studied. The results show that with the increase of the draw ratio, the diameters of filament and fiber decrease; while the degree of orientation arrangement and crystallinity of the fibers is obviously improved and the breaking strength and initial modulus of the filaments increase. As the maximum draw ratio reaches 1.7, the breaking strength and initial modulus of the filament are 2.64 times and 4.2 times as compared to those of the control sample respectively.

Abstract: The Polyvinyl alcohol (PVA)/ multiwall carbon nanotubes (MWNT) nanofibers were prepared by electrospun assisted by high-energy sonication. The morphological structures and characterized of the nanofibers were observed via scanning electronic microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR). Electrical properties and mechanical properties of the film have been tested. The results indicate that the introduction of ATO nanoparticles into the polymer matrix has a significant effect on the thermal stability properties of PVA and a strong interaction between PVA and MWNTs.