scholarly journals Enhancement of Volumetric Capacitance of Binder-Free Single-Walled Carbon Nanotube Film via Fluorination

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1135
Author(s):  
Olga A. Gurova ◽  
Vitalii I. Sysoev ◽  
Egor V. Lobiak ◽  
Anna A. Makarova ◽  
Igor P. Asanov ◽  
...  

Robust electrode materials without the addition of binders allow increasing efficiency of electrical storage devices. We demonstrate the fabrication of binder-free electrodes from modified single-walled carbon nanotubes (SWCNTs) for electrochemical double-layer capacitors (EDLCs). Modification of SWCNTs included a sonication in 1,2-dichlorobenzene and/or fluorination with gaseous BrF3 at room temperature. The sonication caused the shortening of SWCNTs and the splitting of their bundles. As a result, the film prepared from such SWCNTs had a higher density and attached a larger amount of fluorine as compared to the film from non-sonicated SWCNTs. In EDLCs with 1M H2SO4 electrolyte, the fluorinated films were gradually defluorinated, which lead to an increase of the specific capacitance by 2.5–4 times in comparison with the initial values. Although the highest gravimetric capacitance (29 F g−1 at 100 mV s−1) was observed for the binder-free film from non-modified SWCNT, the fluorinated film from the sonicated SWCNTs had an enhanced volumetric capacitance (44 F cm−3 at 100 mV s−1). Initial SWCNT films and defluorinated films showed stable work in EDLCs during several thousand cycles.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Matei Raicopol ◽  
Alina Pruna ◽  
Luisa Pilan

The composites based on carbon nanotubes (CNTs) and conducting polymers (CPs) are promising materials for supercapacitor devices due to their unique nanostructure that combines the large pseudocapacitance of the CPs with the fast charging/discharging double-layer capacitance and excellent mechanical properties of the CNTs. Here, we report a new electrochemical method to obtain polypyrrole (PPY)/single-walled carbon nanotube (SWCNT) composites. In the first step, the SWCNTs are covalently functionalized with monomeric units of pyrrole by esterification of acyl chloride functionalized SWCNTs and N-(6-hydroxyhexyl)pyrrole. In the second step, the PPY/SWCNTs composites are obtained by copolymerizing the pyrrole monomer with the pyrrole units grafted on SWCNTs surface using controlled potential electrolysis. The composites were further characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The results showed good electrochemical charge storage properties for the synthesized composites based on PPY and SWCNTs covalently functionalized with pyrrole units making them promising electrode materials for high power supercapacitors.


RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 28135-28145
Author(s):  
Ahmed I. A. Abd El-Mageed ◽  
Takuji Ogawa

For the first time, using scanning probe microscopy, the supramolecular structures of terbium porphyrin double-decker complexes were observed on single-walled carbon nanotubes surfaces, where the molecules formed a well-ordered self-assembled array.


2018 ◽  
Vol 5 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Subrat Kumar Jena ◽  
S. Chakraverty

Abstract In this paper, Differential Quadrature Method (DQM) is applied to investigate free vibration of Single Walled Carbon Nanotubes (SWCNTs) with exponentially varying stiffness based on non-local Euler-Bernoulli beam theory. Application of DQ method in the governing differential equation converts the problem to a generalized eigenvalue problem and its solution gives frequency parameters. Convergence of the results show that DQM solutions converge fast. In this article, a detailed investigation has been reported and MATLAB code has been developed to analyze the numerical results for different scaling parameters as well as for four types of boundary conditions. Present results are compared with other available results and are found to be in good agreement.


2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Guiru Gu ◽  
Yunfeng Ling ◽  
Runyu Liu ◽  
Puminun Vasinajindakaw ◽  
Xuejun Lu ◽  
...  

We report an all-printed thin-film transistor (TFT) on a polyimide substrate with linear transconductance response. The TFT is based on our purified single-walled carbon nanotube (SWCNT) solution that is primarily consists of semiconducting carbon nanotubes (CNTs) with low metal impurities. The all-printed TFT exhibits a high ON/OFF ratio of around 103and bias-independent transconductance over a certain gate bias range. Such bias-independent transconductance property is different from that of conventional metal-oxide-semiconductor field-effect transistors (MOSFETs) due to the special band structure and the one-dimensional (1D) quantum confined density of state (DOS) of CNTs. The bias-independent transconductance promises modulation linearity for analog electronics.


Author(s):  
Taza Gul ◽  
Ramla Akbar ◽  
Zafar Zaheer ◽  
Iraj S Amiri

The mutual result of the magnetic field and Marangoni convection against the thin liquid film of Casson fluid, blood-based carbon nanotube nanofluid has been fruitfully discussed in this article. The influence of various model constraints is focused on velocity, heat transfer, pressure distribution, skin friction and Nusselt number through graphical illustration. In addition, we witness that the thermal field of liquid raises with the growing value of [Formula: see text] and this upsurge is more in single-walled carbon nanotubes and is more dominant than multi-walled carbon nanotubes. The controlling approach of the homotopy analysis method has been used for velocity and temperature distribution. For authentication, the achieved results have been associated with the numerical (ND-Solve) method and displayed. This investigation shows that the velocity profile in the case of Casson fluid single-walled carbon nanotube–blood nanofluid is comparatively less affected and the temperature field of single-walled carbon nanotube–blood nanofluid dominates multi-walled carbon nanotube–blood nanofluid.


2018 ◽  
Vol 284 ◽  
pp. 20-24
Author(s):  
E.S. Sergeeva

Currently, composite materials composed of a matrix and reinforcing components are widely used as a structural material for various engineering devices designed to operate under extreme loads of different types. By modifying a composite with structure-sensitive inclusions, such as a single-wall carbon nanotube, the mechanical properties, especially elastic characteristics, of the resulting material can be significantly improved. The results of investigation of a single-walled carbon nanotubes chirality influence on its elastic properties are presented. Various configurations of nanotubes, such as zigzag and armchair are considered. The dependences of the nanotube bulk modulus and shear modulus of its diameter are shown.


2019 ◽  
Vol 4 (5) ◽  
pp. 1158-1163 ◽  
Author(s):  
Stepan A. Romanov ◽  
Ali E. Aliev ◽  
Boris V. Fine ◽  
Anton S. Anisimov ◽  
Albert G. Nasibulin

We present the state-of-the-art performance of air-coupled thermophones made of thin, freestanding films of randomly oriented single-walled carbon nanotubes (SWCNTs).


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