scholarly journals A workflow to investigate the impacts of weathered multi-walled carbon nanotubes to the mud snail Lymnaea stagnalis

2021 ◽  
Author(s):  
Katrin Weise ◽  
Thomas Kurth ◽  
Irina Politowski ◽  
Carola Winkelmann ◽  
Andreas Schäffer ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Lymnaea Stagnalis ◽  
Physiological State ◽  
Model Organism ◽  
Dry Weight ◽  
Isotopic Labeling ◽  
Mud Snail ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Abstract Although the development and application of nanomaterials is a growing industry, little data is available on the ecotoxicological effects on aquatic organisms. Therefore, we set up a workflow to address the potential uptake of weathered multi-walled carbon nanotubes (wMWCNTs) by a model organism, the pulmonary mud snail Lymnaea stagnalis (L. stagnalis), which plays an important role in the food web. It represents a suitable organism for this approach because as a grazer it potentially ingests large amounts of sedimented wMWCNTs. As food source for L. stagnalis, benthic biofilm was investigated by the use of a transmission electron microscope (TEM) and a scanning electron microscope (SEM) after exposure with wMWCNTs. In addition, isotopic labeling was applied with 14C-wMWCNTs (0.1 mg/L) to quantify fate, behavior, and enrichment of 14C-wMWCNTs in benthic biofilm and in L. stagnalis. Enrichment in benthic biofilm amounted to 529.0 µg wMWCNTs/g dry weight and in L. stagnalis to 79.6 µg wMWCNTs/g dry weight. A bioconcentration factor (BCF) for L. stagnalis was calculated (3500 L/kg). We demonstrate the accumulation of wMWCNTs (10 mg/L) in the digestive tract of L. stagnalis in an effect study. Moreover, the physiological markers glycogen and triglycerides as indicators for the physiological state, as well as the RNA/DNA ratio as growth indicator, were examined. No significant differences between exposed and control animals were analyzed for glycogen and triglycerides after 24 days of exposure, but a decreasing trend is recognizable for triglycerides. In contrast, the significant reduction in the RNA/DNA ratio of L. stagnalis indicated an inhibition of growth with a following recovery after depuration. The described workflow enables a comprehensive determination of the fate and the behavior of wMWCNTs specifically and in general all kinds of CNTs in the aquatic environment and therefore contributes to a holistic risk assessment of wMWCNTs.

scholarly journals A Workflow to Investigate the Impacts of Weathered Multi-Walled Carbon Nanotubes to the Mudsnail Lymnaea Stagnalis

2021 ◽  
Author(s):  
Katrin Weise ◽  
Thomas Kurth ◽  
Irina Politowski ◽  
Carola Winkelmann ◽  
Andreas Schäffer ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Lymnaea Stagnalis ◽  
Physiological State ◽  
Model Organism ◽  
Aquatic Organisms ◽  
Dry Weight ◽  
Isotopic Labeling ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Abstract Although the development and application of nanomaterials is a growing industry, little data is available on the ecotoxicological effects on aquatic organisms. Therefore, we set up a workflow to address the potential uptake of weathered multi-walled carbon nanotubes (wMWCNTs) by a model organism, the pulmonary mudsnail Lymnaea stagnalis (L. stagnalis), which plays an important role in the food web. It represents a suitable organism for this approach because as a grazer it potentially ingests large amounts of sedimented wMWCNTs. As food source for L. stagnalis, benthic biofilm was investigated by the use of a transmission electron microscope (TEM), and a scanning electron microscope (SEM) after exposure with wMWCNTs. In addition, isotopic labeling was applied with 14C-wMWCNTs (0.1 mg/L) to quantify fate, behavior and enrichment of 14C-wMWCNTs in benthic biofilm and in L. stagnalis. Enrichment in benthic biofilm amounted to 529.0 µg wMWCNTs/g dry weight and in L. stagnalis to 79.6 µg wMWCNTs/g dry weight. A bioconcentration factor (BCF) for L. stagnalis was calculated (3,500 L/kg). We demonstrate the accumulation of wMWCNTs (10 mg/L) in the digestive tract of L. stagnalis in an effect study. Moreover, the physiological markers glycogen and triglycerides as indicators for the physiological state, as well as the RNA/DNA ratio as growth indicator were examined. No significant differences between exposed and control animals were analyzed for glycogen and triglycerides after 24 d of exposure, but a decreasing trend is recognizable for triglycerides. In contrast, the significant reduction in the RNA/DNA ratio of L. stagnalis indicated an inhibition of growth with a following recovery after depuration. The described workflow enables a comprehensive determination of the fate and the behavior of wMWCNTs in specifically and in general all kinds of CNT in the aquatic environment and therefore contributes to a holistic risk assessment of wMWCNTs.

Highly sensitive compression sensors using three-dimensional printed polydimethylsiloxane/carbon nanotube nanocomposites

2019 ◽  
Vol 30 (8) ◽  
pp. 1216-1224 ◽  
Author(s):  
Mohammad Charara ◽  
Mohammad Abshirini ◽  
Mrinal C Saha ◽  
M Cengiz Altan ◽  
Yingtao Liu
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Carbon Nanotube ◽  
Scanning Electron Microscope ◽  
Three Dimensional ◽  
Multi Walled Carbon Nanotube ◽  
Highly Sensitive ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This article presents three-dimensional printed and highly sensitive polydimethylsiloxane/multi-walled carbon nanotube sensors for compressive strain and pressure measurements. An electrically conductive polydimethylsiloxane/multi-walled carbon nanotube nanocomposite is developed to three-dimensional print compression sensors in a freestanding and layer-by-layer manner. The dispersion of multi-walled carbon nanotubes in polydimethylsiloxane allows the uncured nanocomposite to stand freely without any support throughout the printing process. The cross section of the compression sensors is examined under scanning electron microscope to identify the microstructure of nanocomposites, revealing good dispersion of multi-walled carbon nanotubes within the polydimethylsiloxane matrix. The sensor’s sensitivity was characterized under cyclic compression loading at various max strains, showing an especially high sensitivity at lower strains. The sensing capability of the three-dimensional printed nanocomposites shows minimum variation at various applied strain rates, indicating its versatile potential in a wide range of applications. Cyclic tests under compressive loading for over 8 h demonstrate that the long-term sensing performance is consistent. Finally, in situ micromechanical compressive tests under scanning electron microscope validated the sensor’s piezoresistive mechanism, showing the rearrangement, reorientation, and bending of the multi-walled carbon nanotubes under compressive loads, were the main reasons that lead to the piezoresistive sensing capabilities in the three-dimensional printed nanocomposites.

Photovoltaic properties of multi walled carbon nanotubes - poly(3-octathiophene) conducting polymer blends structures

2013 ◽  
Vol 1493 ◽  
pp. 139-144 ◽  
Author(s):  
Punya A. Basnayaka ◽  
Pedro Villalba ◽  
Manoj K. Ram ◽  
Lee Stefanakos ◽  
Ashok Kumar
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Conducting Polymer ◽  
Photoelectrochemical Cell ◽  
Photovoltaic Properties ◽  
Multi Wall Carbon Nanotubes ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

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.

Comparative studies between the influence of single- and multi-walled carbon nanotubes addition on Gd-123 superconducting phase

2016 ◽  
Vol 30 (36) ◽  
pp. 1650418 ◽  
Author(s):  
A. I. Abou-Aly ◽  
M. Anas ◽  
Shaker Ebrahim ◽  
R. Awad ◽  
I. G. Eldeen
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Phase Formation ◽  
Electrical Network ◽  
Sem And Tem ◽  
Transmission Electron ◽  
Composite Superconductor ◽  
Multi Walled Carbon Nanotubes ◽  
Swcnts And Mwcnts ◽  
Walled Carbon Nanotubes

The effect of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) addition on the phase formation and the superconducting properties of GdBa2Cu3O[Formula: see text] phase has been studied. Therefore, composite superconductor samples of type (CNTs)[Formula: see text] GdBa2Cu3O[Formula: see text], 0.0 [Formula: see text] 0.1 wt.% have been synthesized by a standard solid-state reaction technique. The samples have been characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of XRD show an enhancement in the phase formation up to 0.06 wt.% and 0.08 wt.% for SWCNTs and MWCNTs, respectively. SEM and TEM reveal that CNTs form an electrical network resulting in well-connected superconducting grains. The electrical properties of the prepared samples have been examined by electric resistivity and I–V measurements, and their results reinforce the XRD, SEM and TEM. Consequently, both [Formula: see text] and [Formula: see text] improve as the addition percentage increases up to 0.06 wt.% and 0.08 wt.% for SWCNTs and MWCNTs, respectively.

scholarly journals INFLUENCE OF FUNCTIONALIZED MULTI-WALLED CARBON NANOTUBES ON FILTERABILITY AND MECHANICAL PROPERTIES OF RAYON NANOCOMPOSITE FILAMENTS

2016 ◽  
Vol 3 (01) ◽  
Author(s):  
Holia Onggo ◽  
Rike Yudianti ◽  
Endang Ruchiat
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Carbon Nanotube ◽  
Carbon Nanotube Dispersion ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Nanotube Dispersion ◽  
Scanning Electron

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

Mapping functional groups on oxidised multi-walled carbon nanotubes at the nanometre scale

2014 ◽  
Vol 50 (51) ◽  
pp. 6744-6747 ◽  
Author(s):  
A. E. Goode ◽  
N. D. M. Hine ◽  
S. Chen ◽  
S. D. Bergin ◽  
M. S. P. Shaffer ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Low Dose ◽  
Scanning Transmission Electron Microscope ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Electron Energy Loss ◽  
Walled Cnts

Functional peaks have been mapped across individual multi-walled CNTs with low-dose, monochromated electron energy-loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM).

scholarly journals Optimization of growth temperature of multi-walled carbon nanotubes fabricated by chemical vapour deposition and their application for arsenic removal

2014 ◽  
Vol 32 (4) ◽  
pp. 709-718 ◽  
Author(s):  
S. Mageswari ◽  
S. Kalaiselvan ◽  
P. Syed Shabudeen ◽  
N. Sivakumar ◽  
S. Karthikeyan
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Spectral Studies ◽  
Outer Diameter ◽  
Chemical Vapour Deposition Technique ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractMulti-walled carbon nanotubes have been synthesized at different temperatures ranging from 550 °C to 750 °C on silica supported Fe-Mo catalyst by chemical vapour deposition technique using Cymbopogen flexuous oil under nitrogen atmosphere. The as-grown MWNTs were characterized by scanning electron microscope (SEM), high resolution transmission electron microscope (HRTEM), X-ray diffraction analysis (XRD) and Raman spectral studies. The HRTEM and Raman spectroscopic studies confirmed the evolution of MWNTs with the outer diameter between 20 and 40 nm. The possibility of using as-grown MWNTs as an adsorbent for removal of As (V) ions from drinking water was studied. Adsorption isotherm data were interpreted by the Langmuir and Freundlich equations. Kinetic data were studied using Elovich, pseudo-first order and pseudo-second order equations in order to elucidate the reaction mechanism.

Preparation and Characterization of Polyurethane/Multi-Walled Carbon Nanotubes Composites with Multi Functional Performance

2008 ◽  
Vol 47-50 ◽  
pp. 765-768 ◽  
Author(s):  
Feng Dan Jiang ◽  
Guo Hua Hu ◽  
Li Qun Zhang
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Functional Performance ◽  
Thermoplastic Polyurethane ◽  
Functional Materials ◽  
Nano Composites ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Higher Temperature ◽  
Walled Carbon Nanotubes

A melt blending process was employed to prepare nano-composites based on thermoplastic polyurethane (TPU) and multi-walled carbon nanotubes (MWNT). The content of MWNT filled in TPU was increased till 40phr (parts per hundreds of rubber). Scanning electron microscope (SEM) and transmission electron microscope (TEM) showed that the unmodified MWNT were dispersed uniformly in the TPU matrix beyond expectation. Dynamic mechanical thermal analysis (DMTA) test demonstrated that the nano-composites possessed greatly increased modulus, and the flowing temperature moved to higher temperature with increasing MWNT content. Moreover, the nano-composites exhibited improved wear resistance, evidently increased thermal conductivity, and prominently raised electrical conductivity that might mean the TPU/MWNT nano-composites have potential application as multi-functional materials.

Effect of functionalized multi-walled carbon nanotubes on physicomechanical properties of silicone rubber nanocomposites

2019 ◽  
Vol 53 (22) ◽  
pp. 3157-3168 ◽  
Author(s):  
Milind Shashikant Tamore ◽  
Debdatta Ratna ◽  
Satyendra Mishra ◽  
Navinchandra Gopal Shimpi
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Electron Microscope ◽  
Silicone Rubber ◽  
Rubber Matrix ◽  
Uniform Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Rubber Nanocomposites ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Ethyl-4-aminocinnamate functionalized multi-walled carbon nanotubes–reinforced silicone rubber nanocomposites were developed by means of compounding (two roll-mill) and molding (compression). Meanwhile, multi-walled carbon nanotubes were synthesized using a catalytic chemical vapor deposition technique and functionalized using ethyl-4-aminocinnamate. The as-synthesized and functionalized multi-walled carbon nanotubes were subjected to Raman spectroscopy, Fourier-transform infrared spectroscopy, field emission scanning electron microscope, and transmission electron microscopy to know the presence of the functional group with its shape and size. Further, silicone rubber nanocomposites were subjected to study its mechanical (tensile strength, Young's modulus, and elongation at break), thermal (stability), and physical (swelling index and hardness) properties. The amount of loading of functionalized multi-walled carbon nanotubes was from 0 to 1 wt%. It was observed that with the increase in the amount of functionalized multi-walled carbon nanotubes loading, the properties were found to be increased. This improvement was due to uniform dispersion with the alignment of functionalized multi-walled carbon nanotubes inside the rubber matrix. Moreover, this improvement was due to weak functionalizing materials which make the surface smooth and glossy so as to facilitate uniform dispersion of materials. Also, thermal stability was found to be increased due to shifting of heat uniformly throughout the rubber matrix. Certainly, it reduces the swelling indices of silicone rubber as the chains are closely packed which does not allow a solution to get penetrated. This improvement in properties of silicone rubber nanocomposites was reflected from field emission scanning electron microscope, which shows uniform dispersion with the alignment of functionalized multi-walled carbon nanotubes inside the rubber matrix.

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