Effect of Sidewall Fluorination on the Mechanical Properties of Catalytically Grown Multi-Wall Carbon Nanotubes

2011 ◽  
Vol 1284 ◽  
Author(s):  
Yogeeswaran Ganesan ◽  
Cheng Peng ◽  
Lijie Ci ◽  
Valery Khabashesku ◽  
Pulickel M. Ajayan ◽  
...  

ABSTRACTWe report on the usage of a simple microfabricateddevice, that works in conjunction with a quantitative nanoindenter inside a scanning electron microscope (SEM), for the in situ quantitative tensile testing of individual sidewall fluorinated multi-wall carbon nanotubes (MWNTs). The stress vs. strain curves and the tensile strength values for five fluorinated specimens have been presented and compared to those of pristine MWNT specimens (data reported earlier). The fluorinated specimens were found to deform and fail in a brittle fashion similar to pristine MWNTs. However, sidewall fluorination was found to have considerably degraded the mechanical properties (tensile strength and load bearing capacity) of the MWNTs.

2018 ◽  
Vol 18 (06) ◽  
pp. 1850035
Author(s):  
Punyapriya Mishra ◽  
Narasingh Deep ◽  
Sagarika Pradhan ◽  
Vikram G. Kamble

Carbon nanotubes (CNTs) are widely explained in fundamental blocks of nanotechnology. These CNTs exhibit much greater tensile strength than steel, even almost similar to copper, but they have higher ability to carry much higher currents, they seem to be a magical material with all these mentioned properties. In this paper, an attempt has been made to incorporate this wonder material, CNT, (with varying percentages) in polymeric matrix (Poly methyl methacrylate (PMMA)) to create a new conductive polymer composite. Various mechanical tests were carried out to evaluate its mechanical properties. The dielectric properties such as dielectric loss and dielectric constant were evaluated with the reference of temperature and frequency. The surface structures were analyzed by Scanning Electron Microscope (SEM).


2011 ◽  
Vol 690 ◽  
pp. 339-342
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hiroyuki Fukuda ◽  
Junko Umeda

By using light metal (Mg, Al, Ti) powders coated with un-bundled multi-wall carbon nanotubes (MWCNTs) via wet process, powder metallurgy (P/M) light metal matrix composite reinforced with un-bundled nanotubes was prepared by spark plasma sintering (SPS) and subsequently hot extrusion process. The microstructure and mechanical properties of the composites were evaluated. In the case of pure titanium, the distribution of CNTs and in-situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyzer. The mechanical properties of TMC were significantly improved by the additive of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of tensile specimens were analyzed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed. In the case of Mg-Al alloys, in-situ formation of Al2MgC2compounds at the interface between CNTs and Mg-matrix occurred and effective for the tensile transfer loading, and resulted in the increment of tensile strength of the composite material.


2000 ◽  
Vol 9 (4) ◽  
pp. 096369350000900 ◽  
Author(s):  
C. Gonzalez ◽  
J. Llorca

The effect of processing on the mechanical properties of Sigma 1140+ SiC fibres was studied through tensile tests carried out on pristine Sigma 1140+ SiC fibres and on fibres extracted from a Ti-6A1-4V-matrix composite. The elastic modulus and the tensile strength were computed after measuring carefully the fibre diameter. The characteristic fibre strength was reduced by 20% and the Weibull modulus by half during composite processing. The analysis of the fracture surfaces in the scanning electron microscope showed that the strength-limiting defects were located around the tungsten core in pristine fibres and predominantly at the surface in fibres extracted from the composite panels. These latter defects were nucleated by the mechanical stresses generated on the fibres during the panel consolidation.


Author(s):  
B. F. Luan ◽  
L. Q. Yang ◽  
T. G. Wei ◽  
K. L. Murty ◽  
C. S. Long ◽  
...  

To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.


2011 ◽  
Vol 1297 ◽  
Author(s):  
Michael S. Lowry ◽  
Alfredo Rayms-Keller ◽  
Karen J. Long ◽  
Francisco Santiago ◽  
Victor H. Gehman ◽  
...  

ABSTRACTCarbon nanotubes (CNTs) are appealing materials for biomedical applications due to their unique chemical, electrical and mechanical properties. The emphasis of the present work is on controlling the structure and symmetry of carbon nanotubes by imposing an applied stress at the CNT growth site. CNTs were grown under these conditions using standard chemical vapor deposition (CVD) techniques and were subsequently characterized with a scanning electron microscope; the methodology and implications of this approach are discussed herein.


2013 ◽  
Vol 750-752 ◽  
pp. 671-674
Author(s):  
Rong Hua Zhang ◽  
Yong An Zhang ◽  
Bao Hong Zhu

In this paper, the Al-8.5Fe-1.3V-1.7Si alloys were fabricated by spray forming and extrusion process. The microstructure and mechanical properties of the alloy were investigated by means of metallographic, scanning electron microscope and tensile test. The results indicate that the tensile strength of the extrued alloys can reach 353MPa, the yield strength 300MPa, elongation 19.12%, at room temperature. At 250°C, the tensile strength of the extrued alloys can reach 221MPa, the yield strength 208MPa, elongation 13.33%.


2013 ◽  
Vol 1493 ◽  
pp. 139-144 ◽  
Author(s):  
Punya A. Basnayaka ◽  
Pedro Villalba ◽  
Manoj K. Ram ◽  
Lee Stefanakos ◽  
Ashok Kumar

AbstractIn the present study, we have studied photoelectrochemical properties of poly(3-octathiophene) (P3OT), blending with multi-wall carbon nanotubes (MWCNTs). P3OT blended with MWCNTs was characterized using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Raman spectroscope, and Cyclic Voltammetry (CV) techniques, respectively. The photoelectrochemical current of the MWCNs-P3OT based cell under illumination was investigated by applying a voltage. The blend consisting of 10% MWCNTs in P3OT gave the promising photocurrent in 0.2 M tetra-butyl-ammonium-tetrafluoroborate (TBATFB), electrolyte. Experimental results indicate that photocurrent obtained from MWCNT-P3OT was three times higher than simple P3OT-based conducting polymer. The electrochemical responses of MWCNT-P3OT films in different electrolytes such as 0.2M TBATFB, 0.2 M LiClO4, 1 M H2SO4 and 0.2 M LiBF6 were investigated for comparative photocurrent properties of the photoelectrochemical cell.


2007 ◽  
Vol 546-549 ◽  
pp. 1515-1520
Author(s):  
Zhuo Zhang ◽  
Hong Jun Guo ◽  
Wei He ◽  
Wen Xion Zhang

The thermotropic liquid crystalline copolyamide (TLCPa) was synthesized and the in situ composites for TLCPa/Polyamides 66 (PA66) were prepared by melting extrusion. As revealed by differential scanning calorimeter (DSC), depression of the melting point and the crystallinity of PA66 indicated that the miscibility was enhanced via intermolecular H-bonds. Characteristic absorption shifts of C=O groups of TLCPa/PA66 in Fourier transform infra-red spectra (FTIR) confirmed the existence of H-bonds. Scanning electron microscope (SEM) observation showed that the shape of TLCPa phase change in matrix with increasing TLCPa content. Mechanical properties of blends were significantly improved by good interface adhesion and TLCPa fibrils generation.


2016 ◽  
Vol 3 (01) ◽  
Author(s):  
Holia Onggo ◽  
Rike Yudianti ◽  
Endang Ruchiat

Carbon nanotube-rayon composite filaments was fabricated by spinning and coagulation of the mixture of 100mL functionalized carbon nanotube dispersion (containing 0.72 g FCNT) and cellulose xanthate in NaOH solution using viscose process. In the process, CNT was functionalized using mixture of acidic solution ( H2SO4/HNO3, 3:1 v/v). Influence of functionalized (FCNT) and non-functionalized carbon nanotubes (nFCNT) on the fabrication of rayon nanocomposite filament was studied. Physical and morphological properties of the nanocomposite filaments were characterized by single filament tenacity tester, photo micrograph, scanning electron microscope (SEM) and transmission electron microscope (TEM). Filterability and mechanical properties of FCNT-rayon nanocomposite filament greatly improved by reducing clogging constant from 1689 to 153 and increasing tenacity from 2.72 to 3.01 g/denier and decreasing elongation from 57.1 to 36.5% respectively compared with those of nFCNT-rayon nanocomposite filament.Keywords: functionalized multi-walled carbon nanotubes, nanocomposite filament, mechanical properties, filterability, dispersion  ABSTRAKRayon nanocomposite filaments telah dibuat melalui proses pemilinan (spinning) dan koagulasi (coagulation) dari campuran 100 mL larutan functionalized carbon nanotube dispersion (FCNT=0,72 g), selulosa santat dalam larutan NaOH melalui proses viskosa. CNT di functionalisasi (FCNT) menggunakan campuran larutan asam (H2SO4/HNO3, 3:1 v/v). Pengaruh fungsionalisasi CNT pada pembuatan rayon nanocomposite filaments dipelajari dengan cara membandingkannya dengan CNT tanpa fungsionalisasi (nFCNT). Sifat fisik dan morfologi dari rayon-nanocomposite filaments dikarakterisasi menggunakan tenacity tester, photo micrograph, scanning electron microscope (SEM) dan transmission electron microscope (TEM). Viskosa FCNT memiliki daya saring (Kw) cukup baik yaitu 155, sedangkan viskosa nFCNT  memiliki daya saring 1689 (tidak baik). Kekuatan mekanik dari FCNT-rayon nanocomposite filaments berturut turut adalah 3,01 g/denier (tenacity), dan 36,5% (elongation), lebih baik dibandingkan dengan nFCNT-rayon nanocomposite filament: 2,72 g/denier (tenacity) dan 57,1% (elongation).Kata kunci: fungsionalisasi multi-walled carbon nanotubes, rayon-nanocomposite filament, sifat mekanik, daya saring, dispersi


2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaojian Cao ◽  
Han Zhang ◽  
Jun Yu ◽  
Tianchong Yu ◽  
Yuxing Qing

Determination of the mechanical properties of rock containing pre-existing cracks under tension condition is of great significance to understand the failure process of rock in engineering. This paper presents the experimental results of sandstone containing pre-existing cracks under Brazilian compression. The characteristics of the microcracks were analyzed by a scanning electron microscope. The results show that the rock containing pre-existing cracks has an obvious anisotropic characteristic. When the crack inclination is 45°, the rock has the minimum tensile strength and the weakest axial deformation resistance.


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