Composites of Polyvinyl Alcohol and Carbon (Coils, Undoped and Nitrogen Doped Multiwalled Carbon Nanotubes) as Ethanol, Methanol and Toluene Vapor Sensors

2011 ◽  
Vol 11 (11) ◽  
pp. 10211-10218 ◽  
Author(s):  
Márcia W. C. C. Greenshields ◽  
Ivo A. Hümmelgen ◽  
Messai A. Mamo ◽  
Ahmed Shaikjee ◽  
Sabelo D. Mhlanga ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Polyvinyl Alcohol ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Toluene Vapor ◽  
Vapor Sensors

scholarly journals Temperature Dependence of Sensors Based on Silver-Decorated Nitrogen-Doped Multiwalled Carbon Nanotubes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Eduardo Gracia-Espino ◽  
Bernabé Rebollo-Plata ◽  
Hugo Martínez-Gutiérrez ◽  
Emilio Muñoz-Sandoval ◽  
Florentino López-Urías ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Density Functional ◽  
Chemical Vapor ◽  
Ag Nps ◽  
Multiwalled Carbon ◽  
Detection Mechanism ◽  
Nitrogen Doped ◽  
Vapor Sensors

Vapor sensors are easily fabricated onto alumina substrates using foils of silver-decorated nitrogen-doped multiwalled carbon nanotubes (CNX-MWNTs-Ag) as active sensing material. The vapor sensors are tested using carbon disulfide, acetone, ethanol, and chloroform vapors. The CNX-MWNTs are produced by chemical vapor deposition process and then decorated with 14 nm Ag nanoparticles (Ag-NPs). The samples are characterized using scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. Our results demonstrate that Ag-decorated CNX-MWNTs exhibit a better response and sensitivity when compared with pristine CNX-MWNTs based sensors, making them promising candidates for air-pollutants environmental monitoring. The temperature effect on the sensor performance is also studied; we found that the detection mechanism could be tuned from physisorption, at room temperature, to chemisorption at higher working temperature. Finally, first-principles density functional calculations are carried out to understand the interactions between the systems involved in the sensors, finding good agreement between experimental results and the theoretical approach.

Carbon sponge-type nanostructures based on coaxial nitrogen-doped multiwalled carbon nanotubes grown by CVD using benzylamine as precursor

Carbon ◽  
2017 ◽  
Vol 115 ◽  
pp. 409-421 ◽  
Author(s):  
Emilio Muñoz-Sandoval ◽  
Alejandro J. Cortes-López ◽  
Beatriz Flores-Gómez ◽  
Juan L. Fajardo-Díaz ◽  
Roque Sánchez-Salas ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Nitrogen Doped

Synthesis and characterization of multiwalled carbon nanotubes-protoporphyrin IX composites using acid functionalized or nitrogen doped carbon nanotubes

2016 ◽  
Vol 70 ◽  
pp. 65-75 ◽  
Author(s):  
Miriam M. Tostado-Plascencia ◽  
Marciano Sanchez-Tizapa ◽  
Adalberto Zamudio-Ojeda ◽  
Amaury Suárez-Gómez ◽  
Rocío Castañeda-Valderrama ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Protoporphyrin Ix ◽  
Synthesis And Characterization ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Tailoring the Seebeck Coefficient of Spray-Coated Poly(3,4-ethylenedioxythiophene): Poly(styrenesulfonate) Films with Nitrogen Doped Multiwalled Carbon Nanotubes

2020 ◽  
Vol 20 (6) ◽  
pp. 3576-3581
Author(s):  
Ruben Sarabia-Riquelme ◽  
Camila Gomez ◽  
Dali Qian ◽  
John Craddock ◽  
Matthew Weisenberger
Keyword(s):  
Carbon Nanotubes ◽  
Seebeck Coefficient ◽  
Multiwalled Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Composite Films ◽  
Spray Coating ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Mwcnt Concentration ◽  
Polyethylene Terephthalate Substrate

The thermoelectric properties of flexible thin films fabricated from two commercial poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) formulations filled with multiwalled carbon nanotubes (MWCNT) and nitrogen-doped MWCNT (N-MWCNT) were investigated. A simple spray-coating method for the fabrication of such flexible films on a polyethylene terephthalate substrate was developed. While increasing the MWCNT concentration had little effect on the thermoelectric properties, increasing the N-MWCNT concentration resulted in the emergence of an overall n-type semiconducting behavior and, thereby, tailoring the Seebeck coefficient of the composite films from p-type to n-type was shown. The Seebeck coefficient of the two PEDOT:PSS formulation films was inverted from 4.1 to −13.3 μV/K and from 12.5 to −10.9 μV/K respectively, with increasing N-MWCNT concentration from 0 to 95 wt.%. The importance of these results for future work stems from the possibility of tailoring the behavior of a typical p-type polymer such as PEDOT:PSS and the effect that the polymer conductive grade has on the switching concentration.

Influence of growth temperature on the structure, composition and bonding character of nitrogen-doped multiwalled carbon nanotubes

2011 ◽  
Vol 26 (3) ◽  
pp. 443-448 ◽  
Author(s):  
Yu Zhang ◽  
Lujun Pan ◽  
Bin Wen ◽  
Xiaoyang Song ◽  
Chenguang Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Growth Temperature ◽  
Multiwalled Carbon ◽  
Nitrogen Doped ◽  
Image Position

Abstract

scholarly journals Nitrogen-Doped Multiwalled Carbon Nanotubes Inhibit Fat Deposition via Immunomodulatory Actions

2021 ◽  
Author(s):  
Haifang Li ◽  
Xue Xiao ◽  
Geng Hu ◽  
Dalin He ◽  
Wenqian Zhang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Mammalian Cells ◽  
Fat Metabolism ◽  
Fat Deposition ◽  
The Body ◽  
Inflammatory Factors ◽  
Multiwalled Carbon ◽  
Nitrogen Doped

Abstract Multiwalled carbon nanotubes (MWCNTs) offer immense opportunities to deliver drug and biomolecules to targeted tissues. However, it’s unclear for us about their effects on fat metabolism. Here, we demonstrate that nitrogen-doped carboxylate-functionalized MWCNTs (N-MWCNTs) inhibit fat deposition both in vivo and in vitro primarily by suppressing adipogenesis. N-MWCNTs show good biocompatability in HEK293 mammalian cells. Intramuscular administration of N-MWCNTs does not affect the body weight gain and feed intake of mice, but reduces the fat mass. In in vitro-cultured adipocytes, N-MWCNTs suppress fat accumulation, accompanying with decreased and increased expression of adipogenic and lipolysis genes, respectively. Transcriptome analysis further certified the N-MWCNT alteration of fat metabolism-related genes. Interestingly, we observed the phagocytosis of N-MWCNTs by macrophage-like cells via TEM imaging. The mRNA sequencing data also showed remarkable variation of the genes involved in TLRs pathway, ultimately leading to down- or up-regulation of inflammatory factors, of which Tnfα, Il1, Il7, Il10, and Il12 are decreased, whereas Il6 and Il11 are increased. In conclusion, N-MWCNTs induce the production of inflammatory cytokines through immune responses, which trigger the reduction of fat deposition. These findings support the usage of N-MWCNTs as a promising delivery for anti-obesity agents.

scholarly journals Dopamine-derived nitrogen-doped carboxyl multiwalled carbon nanotube-modified graphite felt with improved electrochemical activity for vanadium redox flow batteries

2020 ◽  
Vol 7 (7) ◽  
pp. 200402
Author(s):  
Qiang Li ◽  
Anyu Bai ◽  
Tianyu Zhang ◽  
Song Li ◽  
Hong Sun
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Synergetic Effect ◽  
Electrochemical Activity ◽  
Vanadium Redox Flow Battery ◽  
Multiwalled Carbon ◽  
Graphite Felt ◽  
Nitrogen Doped ◽  
Effect Of Oxygen ◽  
Vanadium Redox

Improving the electrochemical activity of electrodes is essential to the development of vanadium redox flow battery (VRFB). In this work, we prepared a novel electrode with the modification of nitrogen-doped carboxyl multiwalled carbon nanotubes using dopamine as an eco-friendly nitrogen source (carboxyl MWCNT@PDAt). Characterization and electrochemical measurements reveal that the synthesized carboxyl MWCNT@PDAt-modified graphite felt electrode (carboxyl MWCNT@PDAt/GF) exhibits excellent electrochemical performance toward VO 2+ / V O 2 + reaction. Superior battery performance was obtained with the energy efficiency of 80.54% at a current density of 80 mA cm −2 . Excellent durability of the carboxyl MWCNT@PDAt/GF electrode was confirmed by long-term charge/discharge tests. The enhanced reaction kinetics of VO 2+ / V O 2 + is ascribed to the synergetic effect of oxygen and nitrogen containing groups on graphite felt surface and the presence of nitrogen-doped carboxyl multiwalled carbon nanotubes (MWCNT). The facile approach proposed in this paper provides a new route to the fabrication of electrode with excellent performance for VRFB.

Tearing open nitrogen-doped multiwalled carbon nanotubes

2008 ◽  
Vol 18 (35) ◽  
pp. 4143 ◽  
Author(s):  
Mark S. Meier ◽  
Rodney Andrews ◽  
David Jacques ◽  
Kelby B. Cassity ◽  
Dali Qian
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
Nitrogen Doped
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