scholarly journals Microscopy and Spectroscopy Characterization of Carbon Nanotubes Grown at Different Temperatures Using Cyclohexanol as Carbon Source

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Elsa G. Ordoñez Casanova ◽  
Héctor A. Trejo Mandujano ◽  
Manuel Román Aguirre
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Morphological Changes ◽  
Spray Pyrolysis Technique ◽  
Product Yield ◽  
Structural Morphology ◽  
Transmission Electron ◽  
Different Temperatures

We present the structural and spectroscopy characterization of carbon nanotubes (CNTs) grown by the spray pyrolysis technique, using ferrocene as catalyzer and cyclohexanol as the carbon source, and synthetized in a temperature range of 750 to 1000°C. The structural morphology was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The spectroscopy response was obtained by UV-Vis and Raman spectroscopy. We observed morphological changes and found that the product yield seems to increase with temperature. The optical characterization corroborated the presence of n – π∗ transitions and Van Hove singularities as result of possible electrical conductivity changes.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

scholarly journals Fabrication and Characterization of Solid Composite Yarns from Carbon Nanotubes and Poly(dicyclopentadiene)

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 717 ◽  
Author(s):  
Wenbo Xin ◽  
Joseph Severino ◽  
Arie Venkert ◽  
Hang Yu ◽  
Daniel Knorr ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Strengthening Mechanism ◽  
Composite Yarn ◽  
Transmission Electron ◽  
Frictional Forces ◽  
Mechanical Consolidation

In this report, networks of carbon nanotubes (CNTs) are transformed into composite yarns by infusion, mechanical consolidation and polymerization of dicyclopentadiene (DCPD). The microstructures of the CNT yarn and its composite are characterized by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and a focused ion beam used for cross-sectioning. Pristine yarns have tensile strength, modulus and elongation at failure of 0.8 GPa, 14 GPa and 14.0%, respectively. In the composite yarn, these values are significantly enhanced to 1.2 GPa, 68 GPa and 3.4%, respectively. Owing to the consolidation and alignment improvement, its electrical conductivity was increased from 1.0 × 105 S/m (raw yarn) to 5.0 × 105 S/m and 5.3 × 105 S/m for twisted yarn and composite yarn, respectively. The strengthening mechanism is attributed to the binding of the DCPD polymer, which acts as a capstan and increases frictional forces within the nanotube bundles, making it more difficult to pull them apart.

Efficient synthesis of carbon nanotubes with improved surface area by low-temperature solvothermal route from dichlorobenzene

2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Gantigaiah Krishnamurthy ◽  
Sarika Agarwal
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Source ◽  
Surface Area ◽  
Heating Temperature ◽  
Outer Diameter ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractThe synthesis of well-aggregated carbon nanotubes in the form of bundles was achieved by the catalytic reduction of 1,2-dichlorobenzene by a solvothermal approach. The use of 1,2-dichlorobenzene as a carbon source yielded a comparably good percentage of carbon nanotubes in the range of 60–70 %, at a low reaction temperature of 200°C. The products obtained were analysed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy techniques. The X-ray diffraction studies implied the presence of pure, crystalline, and well-ordered carbon nanotubes. The scanning electron and transmission electron microscopic images revealed the surface morphology, dimensions and the bundled form of the tubes. These micrographs showed the presence of multi-walled carbon nanotubes with an outer diameter of 30–55 nm, inner diameter of 15–30 nm, and lengths of several hundreds of nanometers. Brunauer-Emmett-Teller-based N2 gas adsorption studies were performed to determine the surface area and pore volume of the carbon nanotubes. These carbon nanotubes exhibit a better surface area of 385.30 m2 g−1. In addition, the effects of heating temperature, heating time, amount of catalyst and amount of carbon source on the product yield were investigated.

Synthesis and Characterization of Superfine Nanostructure Manganese Dioxide Spontaneously Coated onto Carbon Nanotubes

2011 ◽  
Vol 364 ◽  
pp. 398-401
Author(s):  
Johari Md Salleh ◽  
Aziah Buang Nor ◽  
Muhammad Zamir Othman
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Manganese Dioxide ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Transmission Electron ◽  
Before And After ◽  
Cnts Surface ◽  
Thermal Stability Of

Manganese dioxide nanostructered (MnO2) was coated onto carbon nanotubes (CNTs) by simple immersion of the CNTs into a KMnO4 aqueous solution. The morphology of the CNTs before and after MnO2 deposition was examined using field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The superfine coral-like MnO2 deposited and fully covered on the CNTs surface at pH 8. At pH 2 and 6 the MnO2 deposited as the superfine nanorod structure. The superfine MnO2 phase was identified as Birnessite-type MnO2 by X-ray powder diffraction and FESEM. The thermal stability of the superfine nanostructure MnO2 coated CNTs is increase based on the TGA with the weight loss of 4% at 400°C to 900°C.

scholarly journals Imaging and Characterization of Molecules and One-Dimensional Crystals Formed within Carbon Nanotubes

MRS Bulletin ◽  
2004 ◽  
Vol 29 (4) ◽  
pp. 265-271 ◽  
Author(s):  
J. Sloan ◽  
D.E. Luzzi ◽  
A.I. Kirkland ◽  
J.L. Hutchison ◽  
M.L.H. Green
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Single Walled Carbon Nanotubes ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
One Dimensional ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

AbstractThe imaging and characterization of individual molecules and atomically thin, effectively one-dimensional crystals of rock salt and other halides encapsulated within single-walled carbon nanotubes are reviewed in this article. These species were imaged by conventional and super-resolved high-resolution transmission electron microscopy and by scanning tunneling microscopy, revealing the detailed atomic structure of these nanoscopic species.

Synthesis and Electrical Characterization of Tin Oxide Nanostructures

2009 ◽  
Vol 1178 ◽  
Author(s):  
Olivia Maria Berengue ◽  
Cleocir J. Dalmaschio ◽  
Tiago G. Conti ◽  
Adenilson J. Chiquito ◽  
Edson R. Leite
Keyword(s):  
Electron Microscopy ◽  
Electrical Characterization ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Current Voltage ◽  
Different Temperatures ◽  
Light Excitation ◽  
Resistance Curves

AbstractSn3O4 nanobelts were grown by a carbothermal evaporation process of SnO2 powders in association with the well known vapour-solid mechanism (VS). The nanobelts crystal structure was investigated by x-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), raman spectroscopy and field emission gun scanning electron microscopy (FEG-SEM). The structural and morphological characterization has confirmed the growth of single crystal nanobelts. The electrical characterization (current-voltage, temperature-dependent resistance curves) of individual Sn3O4 nanobelts was performed at different temperatures and light excitation. The experiments revealed a semiconductor – like character as evidenced by the resistance decreasing at high temperatures. The transport mechanism was identified as the variable range hopping.

scholarly journals Green Synthesis and Characterization of Carbon Nanotubes/Polyaniline Nanocomposites

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Van Hoa Nguyen ◽  
Jae-Jin Shim
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Interfacial Polymerization ◽  
Nickel Foam ◽  
Green Solvents ◽  
X Ray ◽  
Transmission Electron ◽  
Two Phases

Carbon nanotubes/polyaniline (CNT/PANI) nanocomposites were synthesized by the interfacial polymerization of aniline in the presence of CNTs using two green solvents, water and an ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF4]), as the two phases. The formation and incorporation of PANI on the surface of the CNTs were confirmed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy. The analyses showed that the surface of the CNTs was coated with different morphologies of thin PANI layers depending on whether a HCl or HNO3solution was used. The thermal stability of the composites was much better than that of the bare CNTs and pure PANI. The as-prepared composites were also used to modify the nickel foam electrodes for characterization of the electrochemical properties.

Synthesis and Characterization of Ni/CNTs Electrodes and their Supercapacitors Performance

2012 ◽  
Vol 507 ◽  
pp. 48-51
Author(s):  
Fu Liu ◽  
Qian Qian Li ◽  
Si Han Zhang ◽  
Cao Ma ◽  
Quan Zhuang Ren ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Specific Capacitance ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Transmission Electron ◽  
Effective Path ◽  
Nano Size

The Ni/Carbon nanotubes (CNTs) composites for supercapacitor electrode have been synthesized by electroless deposition method. The morphology and structure of Ni/CNTs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The nano-size Ni particles coated the surface of carbon nanotubes. Electrochemical performances of the synthesized composites were investigated by cyclic voltammetry and galvanostatic charge/discharge measurement. The specific capacitance of prepared electrode is up to 281 F/g, which is much higher than acetylene black electrode and pure carbon nanotubes electrode, indicating an effective path for increasing specific capacitance of carbon materials for the appplication of supercapacitors.

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