scholarly journals Optical Response Characteristics of Single-Walled Carbon Nanotube Chirality Exposed to Oxidants with Different Oxidizing Power

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1091
Author(s):  
Yuji Matsukawa ◽  
Kazuo Umemura
Keyword(s):  
Near Infrared ◽  
Three Dimensional ◽  
Detection Sensitivity ◽  
Dimensional Structure ◽  
Single Walled Carbon ◽  
Response Characteristics ◽  
Oxidizing Power ◽  
Nir Absorption ◽  
The Difference ◽  
Walled Carbon Nanotubes

Semiconductor single-walled carbon nanotubes (SWNTs) have unique characteristics owing to differences in the three-dimensional structure (chirality) expressed by the chiral index (n,m), and many studies on the redox characteristics of chirality have been reported. In this study, we investigated the relationship between the chirality of SWNTs and the oxidizing power of oxidants by measuring the near-infrared (NIR) absorption spectra of two double-stranded DNA-SWNT complexes with the addition of three oxidants with different oxidizing powers. A dispersion was prepared by mixing 0.5 mg of SWNT powder with 1 mg/mL of DNA solution. Different concentrations of hydrogen peroxide (H2O2), potassium hexachloroidylate (IV) (K2IrCl6), or potassium permanganate (KMnO4) were added to the dispersion to induce oxidation. Thereafter, a catechin solution was added to observe if the absorbance of the oxidized dispersion was restored by the reducing action of the catechin. We found that the difference in the oxidizing power had a significant effect on the detection sensitivity of the chiralities of the SWNTs. Furthermore, we revealed a detectable range of oxidants with different oxidizing powers for each chirality.

scholarly journals Detection of Redox Properties of (6,5)-Enriched Single-Walled Carbon Nanotubes Using Potassium Permanganate (KMnO4)

2020 ◽  
Vol 6 (2) ◽  
pp. 30
Author(s):  
Yuji Matsukawa ◽  
Kazuo Umemura
Keyword(s):  
Carbon Nanotubes ◽  
Absorption Spectra ◽  
Near Infrared ◽  
Single Walled Carbon Nanotubes ◽  
Redox Properties ◽  
Single Walled Carbon ◽  
Langmuir Adsorption ◽  
Oxidizing Power ◽  
Nir Absorption ◽  
Walled Carbon Nanotubes

It has been reported that even if single-walled carbon nanotubes (SWNTs) are coated with the same polymer, the redox characteristics change of each chirality may differ. Particularly, the addition of hydrogen peroxide (H2O2) minimally affects the near-infrared (NIR) absorption spectra of the dsDNA-(6,5)-enriched SWNT complex (DNA-SWNT complex). Detecting the redox properties of (6,5) chirality using NIR absorption spectra has been one of the issues to be solved. We hypothesized that an oxidizing agent with high oxidizing power is required to detect the absorption spectra of (6,5) chirality. In this study, we used KMnO4, which contains atoms with a high oxidation number. A dispersion was prepared by mixing 0.5 mg of (6,5)-enriched SWNT powder with 1 mg/mL of DNA solution. After adding H2O2 or KMnO4 to this dispersion and oxidizing it, catechin solutions were added to reduce the dispersion. The absorption peak of the DNA-SWNT complex decreased by 23.9% following the addition of KMnO4 (final concentration: 0.5 µM) and recovered 30.7% following the addition of the catechin solution. We revealed that the changes in the absorption spectra change of (6,5) chirality, which could not be detected by H2O2, can be detected by using KMnO4. We also varied the concentration of KMnO4 and verified whether the adsorption of KMnO4 can be modeled as a Langmuir adsorption isotherm.

EXTRACTION OF METALLIC NANOTUBES OF ZEOLITE-SUPPORTED SINGLE-WALLED CARBON NANOTUBES SYNTHESIZED FROM ALCOHOL

NANO ◽  
2007 ◽  
Vol 02 (04) ◽  
pp. 221-226 ◽  
Author(s):  
YUTAKA MAEDA ◽  
MASAHIRO HASHIMOTO ◽  
TADASHI HASEGAWA ◽  
MAKOTO KANDA ◽  
TAKAHIRO TSUCHIYA ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Near Infrared ◽  
Catalytic Decomposition ◽  
Single Walled Carbon Nanotubes ◽  
Selective Extraction ◽  
Raman Spectroscopic ◽  
Single Walled Carbon ◽  
Spectroscopic Analyses ◽  
Nir Absorption ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWNTs) synthesized by catalytic decomposition of an alcohol were purified by extraction. The purified SWNTs were characterized on the basis of visible-near infrared (vis-NIR) absorption, photoluminescence and Raman spectroscopic analyses, scanning electron microscopy (SEM) observation, and thermal analysis. Selective extraction of metallic nanotubes was also achieved by the extraction condition.

scholarly journals Prediction of the Near-Infrared Absorption Spectrum of Single-Walled Carbon Nanotubes Using a Bayesian Regularized Back Propagation Neural Network Model

2021 ◽  
Vol 7 (4) ◽  
pp. 80
Author(s):  
Takao Onishi ◽  
Yuji Matsukawa ◽  
Yuto Yamazaki ◽  
Daisuke Miyashiro
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Carbon Nanotubes ◽  
Absorption Spectra ◽  
Near Infrared ◽  
Infrared Absorption Spectrum ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Response Characteristics ◽  
Walled Carbon Nanotubes

DNA-wrapped single-walled carbon nanotubes (DNA-SWCNTs) in stable dispersion are expected to be used as biosensors in the future, because they have the property of absorption of light in the near infrared (NIR) region, which is safe for the human body. However, this practical application requires the understanding of the DNA-SWCNTs’ detailed response characteristics. The purpose of this study is to predict, in detail, the response characteristics of the absorption spectra that result when the antioxidant catechin is added to oxidized DNA-SWCNTs, from a small amount of experimental data. Therefore, in the present study, we predicted the characteristics of the absorption spectra of DNA-SWCNTs using the Bayesian regularization backpropagation neural network (BRBPNN) model. The BRBPNN model was trained with the catechin concentration and initial absorption peaks as inputs and the absorption spectra after catechin addition as outputs. The accuracy of the predicted absorption peaks and wavelengths after the addition of catechin, as predicted by the BRBPNN model, was within 1% of the error of the experimental data. By inputting the catechin concentrations under hundreds of conditions into this BRBPNN model, we were able to obtain detailed prediction curves for the absorption peaks. This method has the potential to help to reduce the experimental costs and improve the efficiency of investigating the properties of high-cost materials such as SWCNTs.

scholarly journals Rutin-Functionalized Multi-Walled Carbon Nanotubes: Molecular Docking, Physicochemistry and Cytotoxicity in Fibroblasts

Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 173
Author(s):  
Conrado M. S. Neto ◽  
Felipe C. Lima ◽  
Renata P. Morais ◽  
Lucas R. M. de Andrade ◽  
Renata de Lima ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Docking ◽  
Thermal Analyses ◽  
Three Dimensional ◽  
Morphological Structure ◽  
Dose Effect ◽  
Dimensional Structure ◽  
3T3 Fibroblasts ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-Walled Carbon Nanotubes (MWCNT) have been functionalized with rutin through three steps (i. reaction step; ii. purification step; iii. drying step) and their physicochemical properties investigated with respect to morphological structure, thermal analysis, Fourier Transform Infrared Spectroscopy (FTIR), and cytotoxicity. The molecular docking suggested the rutin-functionalized MWCNT occurred by hydrogen bonds, which was confirmed by FTIR assays, corroborating the results obtained by thermal analyses. A tubular shape, arranged in a three-dimensional structure, could be observed. Mild cytotoxicity observed in 3T3 fibroblasts suggested a dose–effect relationship after exposure. These findings suggest the formation of aggregates of filamentous structures on the cells favoring the cell penetration.

scholarly journals In vivo biosensing via tissue-localizable near-infrared-fluorescent single-walled carbon nanotubes

2013 ◽  
Vol 8 (11) ◽  
pp. 873-880 ◽  
Author(s):  
Nicole M. Iverson ◽  
Paul W. Barone ◽  
Mia Shandell ◽  
Laura J. Trudel ◽  
Selda Sen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Near Infrared ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

scholarly journals Enhancing near-infrared photoluminescence from single-walled carbon nanotubes by defect-engineering using benzoyl peroxide

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Lukasz Przypis ◽  
Maciej Krzywiecki ◽  
Yoshiaki Niidome ◽  
Haruka Aoki ◽  
Tomohiro Shiraki ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Conjugated Polymers ◽  
Near Infrared ◽  
Light Emission ◽  
Single Walled Carbon Nanotubes ◽  
Organic Radical ◽  
Defect Engineering ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Selection Of

AbstractSingle-walled carbon nanotubes (SWCNTs) have been modified with ester groups using typical organic radical chemistry. Consequently, traps for mobile excitons have been created, which enhanced the optical properties of the material. The proposed methodology combines the benefits of mainstream approaches to create luminescent defects in SWCNTs while it simultaneously avoids their limitations. A step change was achieved when the aqueous medium was abandoned. The selection of an appropriate organic solvent enabled much more facile modification of SWCNTs. The presented technique is quick and versatile as it can engage numerous reactants to tune the light emission capabilities of SWCNTs. Importantly, it can also utilize SWCNTs sorted by chirality using conjugated polymers to enhance their light emission capabilities. Such differentiation is conducted in organic solvents, so monochiral SWCNT can be directly functionalized using the demonstrated concept in the same medium without the need to redisperse the material in water.

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