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

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.

SOLID-PHASE EXTRACTION OF PHTHALATE ESTERS FROM AQUEOUS SAMPLES USING MESOPOROUS SILICA-COATED MULTIWALLED CARBON NANOTUBES AND THEIR DETERMINATION BY HPLC

NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450054 ◽  
Author(s):  
XIAOYING DENG ◽  
XIAOQING CHEN ◽  
XINYU JIANG
Keyword(s):  
Carbon Nanotubes ◽  
Mesoporous Silica ◽  
Solid Phase Extraction ◽  
Multiwalled Carbon Nanotubes ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Phase Extraction ◽  
Aqueous Samples ◽  
Multiwalled Carbon ◽  
Relative Standard

We report a novel solid-phase extraction adsorbent for the preconcentration of three phthalate esters (PAEs) from aqueous samples. The material was obtained by modifying multiwalled carbon nanotubes (MWCNTs) with mesoporous silica. The structural characterization of the adsorbent was conducted by Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM) and N 2 adsorption–desorption measurement, which confirmed the successful coating of mesoporous silica on MWCNTs and the adsorbent possessing large surface and porous structure. The effects of adsorbent amount, type and volume of eluent and sample pH on extraction efficiency were optimized. Following extraction, the PAEs were quantified by high performance liquid chromatography (HPLC). Under optimal conditions, the recoveries ranged from 89.8% to 96.3%. The calibration plot was linear in the 3–1000 ng⋅mL-1 concentration range, with correlation coefficients ranging from 0.9993 to 0.9995. The repeatability of the method, expressed as relative standard deviation (RSD), ranged from 3.8% to 7.7% (for n = 5). Limits of detection (LODs) were between 0.28 ng mL-1 and 0.53 ng⋅mL-1. The relative recoveries (RR) for spiked river water, pond water and tap water samples were in the ranges of 80.9–98.0%, 82.7–96.1% and 88.3–95.5%, respectively. The results showed that the method obviously had a large potential for preconcentration and determination of PAEs in environmental samples.

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

Electropolymerization of carbon nanotubes/poly-ortho-aminophenol nanocomposite on a stainless steel fiber for the solid-phase microextraction of phthalate esters

RSC Advances ◽  
2014 ◽  
Vol 4 (92) ◽  
pp. 50426-50434 ◽  
Author(s):  
Mansoureh Behzadi ◽  
Ebrahim Noroozian ◽  
Mohammad Mirzaei
Keyword(s):  
Carbon Nanotubes ◽  
Stainless Steel ◽  
Solid Phase Microextraction ◽  
Steel Fiber ◽  
Solid Phase ◽  
Phthalate Esters ◽  
Stainless Steel Fiber

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.

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.

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