scholarly journals Impact of Synthesis Parameters of Multi-Walled Carbon Nanotubes on their Thermoelectric Properties

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3567 ◽  
Author(s):  
Bogumiła Kumanek ◽  
Grzegorz Stando ◽  
Paweł S. Wróbel ◽  
Dawid Janas
Keyword(s):  
Carbon Nanotubes ◽  
Thermoelectric Properties ◽  
Synthesis Temperature ◽  
Injection Rate ◽  
Optimum Synthesis ◽  
Synthesis Parameters ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
The Impact

Carbon nanotubes have been intensively researched for many years because of a wide array of promising properties that they have. In this paper, we present the impact of synthesis parameters on thermoelectric properties of nanocarbon material. We conducted a number of syntheses of multi-walled carbon nanotubes (MWCNTs) at different temperatures (800 and 900 °C) using various amounts of catalyst (2%, 5.5%, and 9.6%) to facilitate the process. We also tested the influence of injection rate of precursor and the necessity of material purification on thermoelectric properties of MWCNTs. The electrical conductivity, thermal conductivity, and Seebeck coefficient were measurement for all samples. Based on these parameters, the values of Power Factor and Figure of Merit were calculated. The results show that the most important parameter in the context of thermoelectric properties is purity of employed MWCNTs. To obtain appropriate material for this purpose optimum synthesis temperature and appropriate content of the catalyst must be selected. The study also reveals that post-synthetic purification of nanocarbon is essential to produce an attractive material for thermoelectrics.

Kinetics and thermodynamics of the sorption of furaltadone from aqueous solutions on magnetic multi-walled carbon nanotubes

2014 ◽  
Vol 70 (6) ◽  
pp. 964-971
Author(s):  
Xu Chen ◽  
Zhen-hu Xiong
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Sorption Data ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Experimental Data Analysis ◽  
Walled Carbon Nanotubes

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L−1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π–π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater.

scholarly journals Assessing the Damage Tolerance of Out of Autoclave Manufactured Carbon Fibre Reinforced Polymers Modified with Multi-Walled Carbon Nanotubes

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1080 ◽  
Author(s):  
Polyxeni Dimoka ◽  
Spyridon Psarras ◽  
Christine Kostagiannakopoulou ◽  
Vassilis Kostopoulos
Keyword(s):  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Reference Material ◽  
Carbon Fibre ◽  
Damage Tolerance ◽  
Energy Levels ◽  
Multi Walled Carbon Nanotubes ◽  
Out Of Autoclave ◽  
Walled Carbon Nanotubes ◽  
The Impact

The present study aims to investigate the influence of multi-walled carbon nanotubes (MWCNTs) on the damage tolerance after impact (CAI) of the development of Out of Autoclave (OoA) carbon fibre reinforced polymer (CFRP) laminates. The introduction of MWCNTs into the structure of CFRPs has been succeeded by adding carbon nanotube-enriched sizing agent for the pre-treatment of the fibre preform and using an in-house developed methodology that can be easily scaled up. The modified CFRPs laminates with 1.5 wt.% MWCNTs were subjected to low velocity impact at three impact energy levels (8, 15 and 30 J) and directly compared with the unmodified laminates. In terms of the CFRPs impact performance, compressive strength of nanomodified composites was improved for all energy levels compared to the reference material. The test results obtained from C-scan analysis of nano-modified specimens showed that the delamination area after the impact is mainly reduced, without the degradation of compressive strength and stiffness, indicating a potential improvement of damage tolerance compared to the reference material. SEM analysis of fracture surfaces revealed the additional energy dissipation mechanisms; pulled-out carbon nanotubes which is the main reason for the improved damage tolerance of the multifunctional composites.

On the Use of Carbon Nanotubes to Develop Durable Structural Electrodes for Self-Sensing Applications

2019 ◽  
Vol 827 ◽  
pp. 458-463
Author(s):  
Sotirios A. Grammatikos ◽  
Morten Melby Dahl ◽  
Vegar Salin Brøndbo ◽  
Angela Daniela La Rosa
Keyword(s):  
Carbon Nanotubes ◽  
Piezoresistive Sensors ◽  
Optimum Synthesis ◽  
Sensing Applications ◽  
Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Cfrp Composite ◽  
Multi Walled Carbon Nanotubes ◽  
Fibre Reinforced Polymer ◽  
Walled Carbon Nanotubes

This paper reports an experimental investigation on embedded polyurethane (PUR) electrodes into a carbon fibre reinforced polymer (CFRP) composite to enable the dependable use of composites as a piezoresistive sensors, among other uses, and pave the way towards advanced structural health monitoring (SHM). To be able to use polyurethane as electrodes, multi-walled carbon nanotubes (MWCNTs) were used as fillers in PUR to increase its electrical conductivity. Various concentrations of MWCNTs in PUR were tested to reveal the optimum synthesis. This was conducted by performing mechanical and electrical property tests of the electrodes, studying the adhesion capabilities between composite matrix and polyurethane electrode and carrying out load-unload testing where the composite acts as a strain sensor.

The Impact of Nanomaterials on Fabrication Silicon Solar Cells by Pulsed Laser Deposition

2020 ◽  
Vol 30 ◽  
pp. 41-54
Author(s):  
Shelan A. Farman ◽  
Muayed K. Ibrahim ◽  
Kadhim A. Aadim
Keyword(s):  
Carbon Nanotubes ◽  
Solar Cells ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Si Solar Cells ◽  
Multi Walled Carbon Nanotubes ◽  
Uv Visible ◽  
Walled Carbon Nanotubes ◽  
The Impact

Nanocarbon structures such as graphene (GR), single-walled carbon nanotubes (SWCNTs) as well as the multi-walled carbon nanotubes (MWCNTs) were deposited on crystalline n-type silicon wafers to fabricate nanoCarbon-Si solar cells. Nanocarbon films deposited on glass and porous silicon (PS) via pulse laser deposition (PLD) with the use of Q-Switching Nd: YAG laser with λ=1064 (nm), Energy (E)=700 (mJ), Repetition rate (f)=6 (HZ) under vacuum condition with 2.5×10-2 (mbar). The surface morphology, structure, and optical Nanocarbon thin films have been examined with the use of X-ray Diffraction (XRD), Atomic force microscope (AFM), FTIR spectrophotometer and UV-visible. In addition, the power conversion efficiency that is related to the prepared solar cells is estimated through J-V characterization. The PCE of all Nanocarbon/PS follows the orders; SWCNTs/PS < MWCNTs/PS< GR/PS.

scholarly journals Effect of Cyrtostachys renda Fiber Loading on the Mechanical, Morphology, and Flammability Properties of Multi-Walled Carbon Nanotubes/Phenolic Bio-Composites

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3049
Author(s):  
Tamil Moli Loganathan ◽  
Mohamed Thariq Hameed Sultan ◽  
Qumrul Ahsan ◽  
Mohammad Jawaid ◽  
Jesuarockiam Naveen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Impact Strength ◽  
Phenolic Resin ◽  
Void Content ◽  
Limiting Oxygen Index ◽  
Fiber Loading ◽  
Milling Method ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
The Impact

This research focuses on evaluating the effect of Cyrtostachys renda (CR) fiber and the impact of adding multi-walled carbon nanotubes (MWCNT) on the morphological, physical, mechanical, and flammability properties of phenolic composites. MWCNT were supplemented with phenolic resin through a dry dispersion ball milling method. Composites were fabricated by incorporating CR fiber in 0.5 wt.% MWCNT-phenolic matrix by hot pressing. Nevertheless, the void content, higher water absorption, and thickness swelling increased with fiber loading to the MWCNT/phenolic composites. The presence of MWCNT in phenolic enhanced the tensile, flexural, and impact strength by as much as 18%, 8%, and 8%, respectively, compared to pristine phenolic. The addition of CR fiber, however, strengthened MWCNT-phenolic composites, improving the tensile, flexural, and impact strength by as much as 16%, 16%, and 266%, respectively, for 50 wt.% loading of CR fiber. The CR fiber may adhere properly to the matrix, indicating that there is a strong interface between fiber and MWCNT-phenolic resin. UL-94 horizontal and limiting oxygen index (LOI) results indicated that all composite materials are in the category of self-extinguishing. Based on the technique for order preference by similarity to the ideal solution (TOPSIS) technique, 50 wt.% CR fiber-reinforced MWCNT-phenolic composite was chosen as the optimal composite for mechanical and flammability properties. This bio-based eco-friendly composite has the potential to be used as an aircraft interior component.

Synthesis of Carbon Nanotubes Using Mesoporous Fe-MCM-41 Catalysts

2006 ◽  
Vol 6 (11) ◽  
pp. 3442-3445
Author(s):  
Jeong-Rae Ko ◽  
Wha-Seung Ahn
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Silica ◽  
Direct Synthesis ◽  
Nano Particles ◽  
Uniform Size ◽  
Optimum Synthesis ◽  
Multi Walled Carbon Nanotubes ◽  
Synthesis Of Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Mcm 41

MWNTs (multi-walled carbon nanotubes) were made by catalytic CVD process using iron-containing mesoporous silica, Fe-MCM-41, with 4 mol% Fe loading prepared by direct synthesis route. Uniform 5 nm size Fe2O3 nano-particles impregnated onto a mesoporous silica support, SBA-15 were also prepared for CNTs synthesis. The catalysts were characterized using XRD, SEM/TEM, N2 physisorption, UV-vis diffuse reflectance and FT-IR spectroscopies. Acetylene gas was introduced as a carbon source, and the gas mixture of Ar:H2:C2H2 = 14:5:1 pyrolyzed at 750 °C for 60 min was found to be the optimum synthesis condition. Fe-MCM-41 due to higher dispersion of nano-sized Fe-species was efficient as catalyst for MWNTs with more uniform size distribution. Cobalt-impregnated Fe-MCM-41 (Co/Fe = 1) produced a small fraction of SWNTs of ca. 2 nm diameter mixed with MWNTs.

Sign in / Sign up

Export Citation Format

Share Document