Preparation of Multi-Walled Carbon Nanotubes (MWNTs)/Polymethyl Methacrylate (PMMA) Hybrid Membranes and their Sorption Performance of Benzene/Cyclohexane

2013 ◽  
Vol 740 ◽  
pp. 550-554
Author(s):  
Li Guang Wu ◽  
Yu Fei Chen ◽  
Yang Rong ◽  
Ting Wang ◽  
Yu Xing Wang

Novel organic-inorganic hybrid membranes of polymethyl methacrylate (PMMA) containing multi-walled carbon nanotubes (MWNTs) were successfully prepared. Then, the swelling adsorption experiments of benzene/cyclohexane mixtures were employed to evaluate the performance of these membranes. Via transmission electron microscopy (TEM), Fourier transform infrared spectrophotometry (FTIR), the effect of surface modification on the morphology and properties of carbon nanotubes and hybrid membranes were studied. The results indicated that the separation performance for benzene/cyclohexane of the hybrid membranes depended on both the polarity of carbon nanotubes and the distribution of MWNTs in PMMA. Because the dispersion of MWNTs were obviously improved after acidification and ammonization modification, the hybrid membranes including modified MWNTs showed higher performance than membranes with un-modified MWNTs. In addition, a large number of polar group were introduced in the MWNTs during modification of acidification and ammonization, which depressed obviously the physical adsorption of cyclohexane by MWNTs. Therefore, these two changes in the properties of MWNTs both improved the separation performance of hybrid membranes.

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

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.


2013 ◽  
Vol 716 ◽  
pp. 373-378
Author(s):  
Qian Zhang ◽  
Xin Bao Gao ◽  
Tian Peng Li

Carbon nanotube/expanded graphite composite material was prepared by expanding the mixture of multi-walled carbon nanotubes and expansible graphite under the condition of high temperature. The microstructure and composition was studied by using SEM and XRD. The study shows that the tubular structure of carbon nanotubes in the composite material is changed by high temperature expanding process, and the microstructure is different with different expanding temperature. When the expanding temperature was 900°C, carbon nanotubes transformed, then attached to the surface of expanded graphite flake, so carbon nanotubes and expanding graphite combined strongly; globular carbon nanotubes attached to the surface of expanded graphite flake at the temperature of 700°C, both were combined much more strongly; carbon nanotubes retained the tube structure at the temperature of 500°C, combination was looser due to the simple physical adsorption. The result shows that the choice of expanding temperature has an important effect on microstructure of carbon nanotube/expanded graphite composite material.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Shuang-Xi Xue ◽  
Qin-Tao Li ◽  
Xian-Rui Zhao ◽  
Qin-Yi Shi ◽  
Zhi-Gang Li ◽  
...  

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.


2007 ◽  
Vol 334-335 ◽  
pp. 685-688
Author(s):  
Dong Lin Zhao ◽  
Xia Li ◽  
Wei Dong Chi ◽  
Zeng Min Shen

The filling of multi-walled carbon nanotubes (MWNTs) with metallic silver nanowires via wet chemistry method was investigated. The carbon nanotubes were filled with long continuous silver nanowires. The carbon nanotubes were almost opened and cut after being treated with concentrated nitric acid. Silver nitrate solution filled carbon nanotubes by capillarity. Carbon nanotubes were filled with silver nanowires after calcinations by hydrogen. The diameters of silver nanowires were in the range of 20-40nm, and lengths of 100nm-10μm. We studied the micromorphology of the silver nanowires filled in carbon nanotubes by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Based on the experimental results, a formation mechanism of the Ag nanowire-filled carbon nanotubes was proposed. And the microwave permittivity of the carbon nanotubes filled with metallic silver nanowires was measured in the frequency range from 2 GHz to 18 GHz. The loss tangent of the carbon nanotubes filled with metallic silver nanowires is high. So the carbon nanotubes filled with metallic silver nanowires would be a good candidate for microwave absorbent.


2015 ◽  
Vol 19 (04) ◽  
pp. 622-630 ◽  
Author(s):  
Saeed Rayati ◽  
Zahra Sheybanifard

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.


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