scholarly journals Revealing the Adsorption Mechanisms of Nitroxides on Ultrapure, Metallicity-Sorted Carbon Nanotubes

ACS Nano ◽  
2014 ◽  
Vol 8 (2) ◽  
pp. 1375-1383 ◽  
Author(s):  
Georgina Ruiz-Soria ◽  
Alejandro Pérez Paz ◽  
Markus Sauer ◽  
Duncan John Mowbray ◽  
Paolo Lacovig ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Adsorption Mechanisms

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

Removal of micropollutants and NOM in carbon nanotube-UF membrane system from seawater

2011 ◽  
Vol 63 (11) ◽  
pp. 2737-2744 ◽  
Author(s):  
Jiyong Heo ◽  
Lesley Joseph ◽  
Yeomin Yoon ◽  
Yong-Gyun Park ◽  
Namguk Her ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Membrane Fouling ◽  
Endocrine Disrupting Compounds ◽  
Membrane System ◽  
Good Alternative ◽  
Adsorption Mechanisms ◽  
Fouling Control ◽  
Membrane Flux ◽  
Seawater Reverse Osmosis ◽  
Walled Carbon Nanotubes

One of the main problems for seawater reverse osmosis desalination is membrane fouling associated with natural organic matter. Bisphenol-A (BPA) and 17α-ethinylestradiol (EE2) are well-known endocrine-disrupting compounds that have been detected in wastewater and seawater. In this study, the contribution of carbon nanotubes (CNTs, single-walled carbon nanotubes) to membrane fouling control and the potential adsorption mechanisms of BPA and EE2 were investigated using artificial seawater (ASW) in a bench scale ultrafiltration (UF) membrane coupled with CNTs. For high ionic strength ASW, UVA254 nm is a good alternative for highly aromatic dissolved organic carbon (DOC) determination, with a very strong linear relationship (R2 ≥ 0.99) with increasing DOC concentrations. Approximately 80% of DOC in ASW was rejected by the CNT-UF system where 31% of DOC was removed due to adsorption by CNTs. The presence of CNTs shows a 20% increase in membrane flux in ASW. A strong linear correlation between retention and adsorption of BPA and EE2 was obtained. The percentage of adsorption/retention of BPA and EE2 in UF-CNTs follows the order: 94.0/96.6 (DI + CNTs, EE2) > 86.2/90.0 (ASW + CNTs, EE2) > 73.6/78.9 (DI + CNTs, BPA) ≥ 74.1/77.3 (ASW + CNTs, BPA) > 29.8/29.8 (ASW, EE2) ≅ 27.3/27.3 (ASW, BPA) ≥ 25.3/25.3 (DI, EE2) ≅ 24.8/24.8 (DI, BPA). This indicates that retention by the UF-CNT system is mainly due to adsorption. Overall, EE2 adsorption was greater than BPA during the UF-CNT experiments, presumably due to the higher hydrophobicity of EE2 than BPA.

scholarly journals Tio2 and carbon nanotubes composites modify capacitive deionization anodes to improve the dechlorination efficiency in desulfurization wastewater

2021 ◽  
Author(s):  
Shuangchen Ma ◽  
Chang Liu ◽  
Yongyi Xu ◽  
Yu Tan ◽  
Dingchang Yang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Surface Area ◽  
High Specific Capacitance ◽  
High Specific Surface Area ◽  
Capacitive Deionization ◽  
Adsorption Mechanisms ◽  
As Adsorption ◽  
Methyl Pyrrolidone ◽  
Desulfurization Wastewater ◽  
Excellent Stability

Abstract A new capacitive deionization (CDI) technology was used to remove Cl− from desulfurization wastewater. TiO2 and carbon nanotubes (CNTs) were combined with N-methyl pyrrolidone (NMP) to form composites by solvothermal method which is coated onto the CDI anode to improve the dechlorination efficiency (DE). The morphology, surface area, wettability, crystal structure and chemical composition of the TiO2/CNTs were characterized. It showed good hydrophilicity (contact angle: 85.9°), high specific surface area (96.68 m²/g) and high specific capacitance (87.6 F/g). The experimental results illustrated that the best DE was achieved by the composites (60%T/C) under 1.2 V with the maximum electrosorption capacity toward 6.5 mg/g, and the TiO2/CNTs composites have excellent stability. The adsorption kinetics analysis was explored and analyzed. Furthermore, TiO2/CNTs composites exhibit excellent DE in actual desulfurization wastewater. The catalysis and adsorption mechanisms of TiO2/CNTs anode were discussed in detail. This study provides a new direction for the application of TiO2/CNTs composites as adsorption materials of CDI in the Cl− of desulfurization wastewater.

Elucidating Adsorption Mechanisms of Phthalate Esters upon Carbon Nanotubes/Graphene and Natural Organic Acid Competitive Effects in Water by DFT and MD Calculations

2015 ◽  
Vol 36 (6) ◽  
pp. 1631-1636 ◽  
Author(s):  
Zhuang Wang ◽  
Se Wang ◽  
Mindong Chen ◽  
Defu Xu ◽  
Lili Tang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Organic Acid ◽  
Phthalate Esters ◽  
Adsorption Mechanisms ◽  
Competitive Effects

Adsorption of sulfamethazine by multi-walled carbon nanotubes: effects of aqueous solution chemistry

RSC Advances ◽  
2015 ◽  
Vol 5 (32) ◽  
pp. 25541-25549 ◽  
Author(s):  
Quanquan Yang ◽  
Guangcai Chen ◽  
Jianfeng Zhang ◽  
Helian Li
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Ionic Strength ◽  
Electrostatic Interactions ◽  
Solution Chemistry ◽  
Adsorption Mechanisms ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The adsorption of SMZ by MWCNTs was studied under varied pH, ionic strength, cations and anions in solution. The results indicated that hydrophobic and electrostatic interactions were the main adsorption mechanisms, and π–π interaction also played an important role.

Introduction of Adsorption Mechanisms Researches on Organic Chemicals and Metallic Ions on CNTs

2013 ◽  
Vol 785-786 ◽  
pp. 432-435 ◽  
Author(s):  
Huan Tang ◽  
Ying Zhao ◽  
Dong Mei Liu ◽  
Jing Lu ◽  
Yi Zou ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Aquatic Environment ◽  
High Potential ◽  
Future Research ◽  
Organic Chemicals ◽  
Metallic Ions ◽  
Factors Affecting ◽  
Adsorption Mechanisms ◽  
Chemical Pollutants

Carbon nanotubes (CNTs) have aroused widespread attention due to their high potential sorption capability for chemical pollutants. This review summarizes the adsorption mechanisms of organic chemicals and metallic ions with CNTs in aquatic environment and the factors affecting the adsorption. For a better understanding of the mechanism, future research works on combining the chemical experience and molecular dynamics (MD) is recommended.

scholarly journals Description of Release Process of Doxorubicin from Modified Carbon Nanotubes

2021 ◽  
Vol 22 (21) ◽  
pp. 12003
Author(s):  
Dorota Chudoba ◽  
Monika Jażdżewska ◽  
Katarzyna Łudzik ◽  
Sebastian Wołoszczuk ◽  
Ewa Juszyńska-Gałązka ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Anticancer Drugs ◽  
Tumour Microenvironment ◽  
Fickian Diffusion ◽  
Release Mechanism ◽  
Acidic Ph ◽  
Release Process ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Mechanisms ◽  
Dynamics Simulations

The article discusses the release process of doxorubicin hydrochloride (DOX) from multi-wall carbon nanotubes (MWCNTs). The studies described a probable mechanism of release and actions between the surface of functionalized MWCNTs and anticancer drugs. The surface of carbon nanotubes (CNTs) has been modified via treatment in nitric acid to optimize the adsorption and release process. The modification efficiency and physicochemical properties of the MWCNTs+DOX system were analyzed by using SEM, TEM, EDS, FTIR, Raman Spectroscopy and UV-Vis methods. Based on computer simulations at pH 7.4 and the experiment at pH 5.4, the kinetics and the mechanism of DOX release from MWNT were discussed. It has been experimentally observed that the acidic pH (5.4) is appropriate for the efficient release of the drug from CNTs. It was noted that under acidic pH conditions, which is typical for the tumour microenvironment almost 90% of the drug was released in a relatively short time. The kinetics models based on different mathematical functions were used to describe the release mechanism of drugs from MWCNTs. Our studies indicated that the best fit of experimental kinetic curves of release has been observed for the Power-law model and the fitted parameters suggest that the drug release mechanism of DOX from MWCNTs is controlled by Fickian diffusion. Molecular dynamics simulations, on the other hand, have shown that in a neutral pH solution, which is close to the blood pH, the release process does not occur keeping the aggregation level constant. The presented studies have shown that MWCNTs are promising carriers of anticancer drugs that, depending on the surface modification, can exhibit different adsorption mechanisms and release.

Single-Wall Carbon Nanotubes Field Emission Properties: A Theoretical Study of the Effects of Cs

2003 ◽  
Vol 800 ◽  
Author(s):  
Brahim Akdim ◽  
Xiaofeng Duan ◽  
Donald A. Shiffler ◽  
Ruth Pachter
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Density Functional ◽  
Single Wall Carbon Nanotubes ◽  
Cathode Plasma ◽  
High Power Microwave ◽  
Single Wall Carbon ◽  
Emission Properties ◽  
Adsorption Mechanisms ◽  
Field Emission Properties

ABSTRACTCarbon nanotubes-based materials appeal for explosive emission, in forming cathode plasma, of interest for high-power microwave tubes. Cs intercalation has demonstrated a significant reduction of the work function of carbon nanotubes, thus improving field emission properties. An understanding of the detailed adsorption effects is important because the current saturation is attributed, in part, to adsorption mechanisms. In this paper, we report a density functional theory study of the effects of Cs on field emission of single-wall carbon nanotubes (SWCNTs), as an example of an approach to be taken for a fundamental understanding of such properties.

scholarly journals Kinetic and Equilibrium Studies of Doxorubicin Adsorption onto Carbon Nanotubes

2020 ◽  
Vol 21 (21) ◽  
pp. 8230 ◽  
Author(s):  
Dorota Chudoba ◽  
Katarzyna Łudzik ◽  
Monika Jażdżewska ◽  
Sebastian Wołoszczuk
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Drug Loading ◽  
Dynamics Simulation ◽  
Multiwalled Carbon ◽  
Equilibrium Studies ◽  
Adsorption Mechanisms ◽  
Pseudo Second Order ◽  
Rate Limiting ◽  
Kinetics Of

This study provides deep insight into the adsorption process of doxorubicin onto different types of carbon nanotubes that have been proved to show attractive properties as a drug delivery system. The main aim of the work was to propose probable adsorption mechanisms and interactions between the anticancer drug and surface of modified and pristine carbon nanotubes at blood pH. The carbon nanotubes were oxidized to optimize the absorbance efficiency relative to that of pristine multiwalled carbon nanotubes. The adsorption isotherm of the modified system was well described by the Temkin equation. It confirms that the adsorption in the system studied involves also hydrogen and covalent bonding and is exothermic in nature. The experimental kinetic curves of adsorption were fitted to different mathematical models to check if the kinetics of doxorubicin adsorption onto the modified multiwalled carbon nanotubes follows a pseudo-second-order model and the chemical sorption is bound to be the rate-limiting. On the basis of the molecular dynamics simulation, it was shown that in vacuo the aggregation tendency of doxorubicin molecules is far more favorable than their adsorption on pristine carbon nanotubes (CNTs). It suggests that only functionalization of the nanotube surface can affect the interaction between doxorubicin and functional groups of the carriers and increases the efficiency of the drug loading process.

The difference in the adsorption mechanisms of magnetic ferrites modified carbon nanotubes

2021 ◽  
pp. 125551
Author(s):  
Jingjing Yao ◽  
Yi Deng ◽  
Siyuan Pan ◽  
Ramon Korna ◽  
Jiayi Wen ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Adsorption Mechanisms ◽  
Magnetic Ferrites ◽  
The Difference ◽  
Modified Carbon Nanotubes
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