scholarly journals Polystyrene-Fe3O4-MWCNTs Nanocomposites for Toluene Removal from Water

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5503
Author(s):  
Thamer Adnan Abdullah ◽  
Tatjána Juzsakova ◽  
Rashed Taleb Rasheed ◽  
Ali Dawood Salman ◽  
Viktor Sebestyen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Bet Surface Area ◽  
Solution Temperature ◽  
Toluene Removal ◽  
Toluene Concentration ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Walled Carbon Nanotubes

In this research, multi-walled carbon nanotubes (MWCNTs) were functionalized by oxidation with strong acids HNO3, H2SO4, and H2O2. Then, magnetite/MWCNTs nanocomposites were prepared and polystyrene was added to prepare polystyrene/MWCNTs/magnetite (PS:MWCNTs:Fe) nanocomposites. The magnetic property of the prepared nano-adsorbent PS:MWCNTs:Fe was successfully checked. For characterization, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and BET surface area were used to determine the structure, morphology, chemical nature, functional groups, and surface area with pore volume of the prepared nano-adsorbents. The adsorption procedures were carried out for fresh MWCNTs, oxidized MWCNTs, MWCNTs-Fe, and PS:MWCNTs:Fe nanocomposites in batch experiments. Toluene standard was used to develop the calibration curve. The results of toluene adsorption experiments exhibited that the PS:MWCNTs:Fe nonabsorbent achieved the highest removal efficiency and adsorption capacity of toluene removal. The optimum parameters for toluene removal from water were found to be 60 min, 2 mg nano-sorbent dose, pH of 5, solution temperature of 35 °C at 50 mL volume, toluene concentration of 50 mg/L, and shaking speed of 240 rpm. The adsorption kinetic study of toluene followed the pseudo-second-order kinetics, with the best correlation (R2) value of 0.998, while the equilibrium adsorption study showed that the Langmuir isotherm was obeyed, which suggested that the adsorption is a monolayer and homogenous.

scholarly journals Biocompatibility Characteristics of Titanium Coated with Multi Walled Carbon Nanotubes—Hydroxyapatite Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Sol Gel ◽  
Pure Titanium ◽  
Cell Proliferation And Differentiation ◽  
Transmission Electron ◽  
Proliferation And Differentiation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.

scholarly journals Carbon Nanofibers from Carbon Nanotubes by 1.2 keVAr+Sputtering at Room Temperature

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shuang-Xi Xue ◽  
Qin-Tao Li ◽  
Xian-Rui Zhao ◽  
Qin-Yi Shi ◽  
Zhi-Gang Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Carbon Nanofibers ◽  
Carbon Nanoparticles ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanowires

Multi-walled carbon nanotubes (MWCNTs) were irradiated by 1.2 keV Ar ion beams for 15–60 min at room temperature with current density of 60 µA/cm2. The morphology and microstructure are investigated by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The results show that carbon nanofibers are achieved after 60 min ion irradiation and the formation of carbon nanofibers proceeds through four periods, carbon nanotubes—amorphous carbon nanowires—carbon nanoparticles along the tube axis—conical protrusions on the nanoparticles surface—carbon nanofibers from the conical protrusions.

Ultrasound promoted green oxidation of alkenes with hydrogen peroxide in the presence of iron porphyrins supported on multi-walled carbon nanotubes

2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Hydrogen Peroxide ◽  
Heterogeneous Catalyst ◽  
Multi Wall Carbon Nanotubes ◽  
Mechanical Stirring ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes

In the present work, oxidation of alkenes with hydrogen peroxide in the presence of meso-tetrakis(4-hydroxyphenyl)porphyrinatoiron(III) chloride supported onto surface of functionalized multi-wall carbon nanotubes (FMWCNT), [ Fe ( THPP ) Cl@MWCNT ], is reported. The simple heterogeneous catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and also thermal analysis. The amount of the catalyst loaded on the nanotubes was determined by atomic absorption spectroscopy. This heterogeneous catalyst proved to be an efficient and green catalyst and was successfully able to activate hydrogen peroxide without any additive toward the oxidation of alkenes in ethanol as a green solvent. Performance of the catalyst in oxidation of various alkenes was inspected under reflux, ultrasonic irradiation and mechanical stirring. Moreover, the catalyst can be reused several times under similar conditions.

Synthesis and Characteristics of Hierarchical Nanostructure Fe3O4 Coated Multi-Walled Carbon Nanotubes

2014 ◽  
Vol 926-930 ◽  
pp. 258-261
Author(s):  
Jing Heng Deng ◽  
Kan Ping Yu ◽  
Jian Guo Xie
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Solvothermal Process ◽  
X Ray ◽  
Hierarchical Nanostructure ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Hierarchical nanostructure Fe3O4/multi-walled carbon nanotubes (Fe3O4/MWCNTs) were prepared by solvothermal process using acid treated MWCNTs and iron acetylacetonate in ethylene glycol as reduction reagent. The materials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET). The results showed that petal-like hierarchical Fe3O4 grew on MWCNTs and the Fe3O4 nanoparticles had diameters in the range of 55-110 nm. It was a facile approach to grow hierarchical nanoFe3O4.

Tribological Properties of Stearic Acid Modified Multi-Walled Carbon Nanotubes in Water

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Yitian Peng ◽  
Zhonghua Ni
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Stearic Acid ◽  
Tribological Properties ◽  
Friction Reduction ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Lubricant Application ◽  
Walled Carbon Nanotubes

The oxidized multiwalled carbon nanotubes (MWCNTs) were modified with stearic acid (SA) molecules. The SA-modified MWCNTs were characterized with scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy. The tribological properties of the oxidized and SA-modified MWCNTs as additives in water were comparatively investigated with a four-ball tester. The results showed the SA-modified MWCNTs in water have better tribological properties including friction reduction and antiwear than oxidized MWCNTs. The possible mechanism of SA-modified MWCNT as an additive in water was discussed. This research provides the opportunity for the lubricant application of MWCNTs.

CVD Synthesis of Multi-Walled Carbon Nanotubes onto Different Catalysts at Low Temperature

NANO ◽  
2018 ◽  
Vol 13 (04) ◽  
pp. 1850036 ◽  
Author(s):  
Guiqiang Diao ◽  
Hao Li ◽  
Hao Liang ◽  
Iryna Ivanenko ◽  
Tetiana Dontsova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Low Temperature ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Lithium Ion ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) were synthesized onto a series of individual and bimetallic catalysts by the chemical vapor deposition (CVD) of acetylene at low temperature (600[Formula: see text]C). The catalysts were prepared by two methods, i.e., precipitation and sol–gel, with two different carriers – MgO and Al2O3. The catalysts were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric (TG) analysis, low-temperature adsorption of nitrogen. The yield of the MWCNTs was calculated in two ways, while the highest yield of 800% was achieved onto the two-component NiO/Co2O3/MgO catalyst, SEM and transmission electron microscopy (TEM) results confirm that uniform tube-like structure MWCNTs with the yield of 410% were obtained onto Co2O3/Al2O3 catalyst. These MWCNTs are smooth and pointing in the same direction. Their tube diameter is about 20[Formula: see text]nm, which is the smallest around all observed MWCNTs. Moreover, nonuniform curved bamboo-like MWCNTs with nozzles in the yield of 760% were obtained onto NiO/V2O3/MgO catalyst. Their diameter ranges from 25[Formula: see text]nm to 50[Formula: see text]nm. Results show that single-component catalyst promotes the growth of uniform and smaller nanotubes. Among the as-grown nanotubes, their specific surface area increases and average pores diameter reduces after the treatment with concentrated nitric acid at reflux and washing condition. The largest specific surface area (305[Formula: see text]m2/g) and average pores diameter (26[Formula: see text]m2/g) are processed to MWCNTs grown onto the NiO/Co2O3/MgO catalyst. MWCNTs with such large structural adsorption characteristics and purity of more than 99% obtained with yield 800% show potential use for preparation of nanocomposites as anode materials in lithium ion batteries.

scholarly journals Synthesis of Multi-Walled Carbon Nanotubes by Chemical Vapour Deposition and Post-Synthesis Treatment by Dielectrophoresis

2021 ◽  
Author(s):  
◽  
Xianming Liu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Electric Field ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Iron Phthalocyanine ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

<p>Carbon nanotubes (CNTs) are a group of pure carbon solid materials that possess one-dimensional structures with diameters down to less than one nanometre. They have interesting physical properties such as very high tensile strength, metallic and semiconducting conductivity, and great potential for applications. This work investigates the synthesis, alignment and purification of multi-walled carbon nanotubes, which were characterized by Electron Microscopy, measurement of electrical properties and Raman scattering. Synthesis of multi-walled carbon nanotubes (MWNTs) was carried out by Chemical Vapour Deposition, using three different precursors: Fe(NO3)3, ferrocene and iron phthalocyanine. Vertically aligned "forests" of large numbers of MWNTs were achieved using ferrocene and iron phthalocyanine as precursors. Products from iron phthalocyanine yield more graphitic CNT nanostructures, as determined by Scanning Electron Microscopy, Transmission Electron Microscopy, Thermogravity Analysis, Raman microscopy and Energy Dispersive X-ray spectroscopy. Patterned growth of vertical MWNTs arrays with a resolution of 2 microns was also obtained, using a predeposited substrate. A High Resolution Transmission Electron Microscope was employed to investigate the inner structures of individual MWNTs, giving well-resolved images of concentric nanostructures with inter-lattice spacings of 0.34 nm. Techniques for purification and manipulation of CNTs are required before CNTs' excellent properties can be exploited. In this thesis, dielectrophoresis (DEP) under high-frequency AC voltages using an array of micron-scale electrodes was adopted as the technique to align MWNTs between these, electrodes. This technique is effective for MWNTs since their long cylindrical structure and the high mobility of their charge carriers allow them to be electrically polarised. As a result, MWNTs experience large DEP forces in an AC electric field. In our experiments, inter-digitated electrodes were used to apply the electric field to CNT suspensions in various solvents. Alignment of CNTs along their axis was achieved within the gaps between adjacent electrodes at a frequency larger than 1.1 MHz, The AC admittance changes between the electrodes were monitored and were observed to be a clear reflection of the accumulation process of MWNTs. Also it was identified that distilled water was a better solvent than ethanol and isopropanol for DEP purpose on MWNTs. In addition, a prototype device was built to selectively purify MWNTs from as-grown samples by combining DEP and re-circulating fluid flow. It was found that this device is able to decrease the impurity content of MWNTs, which is collected on the electrode array, from the suspension of as-grown samples.</p>

A Study of Nanomaterial Dispersion in Solution by Wet-Cell Transmission Electron Microscopy

2008 ◽  
Vol 8 (9) ◽  
pp. 4404-4407 ◽  
Author(s):  
Ryan Franks ◽  
Sean Morefield ◽  
Jianguo Wen ◽  
Dongxiang Liao ◽  
Jorge Alvarado ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Oxide Nanoparticles ◽  
Ultrasonic Power ◽  
Aluminum Oxide Nanoparticles ◽  
Transmission Electron ◽  
Cell Transmission ◽  
Multi Walled Carbon Nanotubes ◽  
Good Characterization ◽  
Walled Carbon Nanotubes ◽  
Forward Process

Preparation of nanomaterial dispersion or nanofluids requires good characterization techniques, including particle size and morphological measurements. A reliable and straight-forward process to characterize and quantify the degree of dispersion and agglomeration is needed. A wet-cell transmission electron microscope (TEM) technique has been developed to make comparisons between sonicated and hand-shaken solutions of both aluminum oxide nanoparticles and multi-walled carbon nanotubes. In each case, the wet-cell TEM technique reveals images of nanoparticles well dispersed in aqueous solutions due in part to the use of ultrasonic power instead of simply manual shaking and stirring. The technique is currently qualitative and shows great potential for a host of nanotechnology applications.

Investigation of Interfacial Interaction and Microstructure for Epoxy/CNTs Nanocomposites by PALS

2008 ◽  
Vol 607 ◽  
pp. 183-185
Author(s):  
Wei Zhou ◽  
Shao Jie Yue ◽  
Jun Jun Wang ◽  
Bo Wang ◽  
Ya Ping Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Interfacial Interaction ◽  
Glass Transition Temperatures ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron ◽  
Volume Size

Epoxy nanocomposites with multi-walled carbon nanotubes (MWNTs) were prepared. The interaction between MWNTs and epoxy matrix and microstructure were systematically investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and the positron annihilation technology (PAT) respectively. The glass transition temperatures were determined by the variation of the free volume size.

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