Surface Modification Effects on CNTs Adsorption of Methylene Blue and Phenol

Norzilah, A.H.; Fakhru’l‐Razi, A.; Choong, Thomas Shean Yaw; Chuah, A. Luqman

doi:10.1155/2011/495676

Cited by 59 publications

(34 citation statements)

References 80 publications

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“…Due to their large specific surface area, small size, and hollow and layered structures, CNTs have been used as adsorbents for the removal of trihalomethanes , xylene , 1,2‐dichlorobenzene , dioxin , zinc(II) , fluoride , lead(II) , chromium(VI) , and mercury(II) . Recently, CNTs have also been used as adsorbents for the removal of dyes from aqueous solution .…”

Section: Introductionmentioning

confidence: 99%

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite

Konicki

Pełech

Mijowska

et al. 2013

CLEAN Soil Air Water

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Magnetic multi‐walled carbon nanotubes‐Fe3C nanocomposite was synthesized by chemical vapor deposition process and was used as an adsorbent for the removal of acid dye Acid Red 88 (AR88) from aqueous solution. The effects of various parameters such as initial AR88 concentration (10–58 mg L−1), pH (3.1–11.3) and temperature (20–60°C) were investigated. The properties of this adsorbent were characterized by X‐ray diffraction, high‐resolution transmission electron microscopy, energy dispersive X‐ray analysis, fourier transform IR, N2 adsorption/desorption isotherms, and particle size distribution by laser diffraction. The experimental data were analyzed by the Langmuir and Freundlich models of adsorption. Equilibrium data fitted well with the Freundlich model. Kinetic adsorption data were analyzed using the Lagergren pseudo‐first‐order kinetic model, the pseudo‐second‐order model and the intraparticle diffusion model. The regression results showed that the adsorption kinetics was more accurately represented by pseudo‐second‐order model. Thermodynamics parameters, Gibbs free energy (ΔG0), enthalpy (ΔH0), and entropy (ΔS0), were calculated. All ΔG0 values were negative. The values of ΔH0 and ΔS0 were −4.70 and −7.98 J mol−1 K−1, respectively, indicating that adsorption of AR88 onto magnetic multi‐walled carbon nanotubes nanocomposites was spontaneous and exothermic in nature.

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Section: Introductionmentioning

confidence: 99%

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite

Konicki

Pełech

Mijowska

et al. 2013

CLEAN Soil Air Water

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“…The effects were attributed to the multiple adsorption interaction mechanisms on the functionalized surface (hydrogen bonding, π−π and electrostatic interactions, etc.). The adsorption capacity of MB on modified nanotubes increased after heat treatment, and decreased after acid modification [56]. The method of removal of MB from aqueous solution using magnetic MWCNTs was proposed [57,58].…”

Section: Adsorptive Properties Of Cntsmentioning

confidence: 99%

A short review on regulation of stability of aqueous suspensions of carbon nanotubes

Manilo¹,

Lebovka²,

Bárány³

2020

Him. Fiz. Tehnol. Poverhni

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This review analyses the authors' recent and related works on electrokinetic properties and colloidal stability of aqueous suspension of multi-walled carbon nanotubes (CNTs) in the presence of surfactants and nanoparticles. Selected adsorptive properties of carbon nanotubes are also considered.The applicability of classical theories of electrophoresis for description of electrophoretic mobility of carbon nanotubes is discussed. Examples on the ζ-potential of CNTs in aqueous suspensions as a function of pH and concentration of electrolytes (KCl, CaCl 2 and AlCl 3 ) are given. Additions of cetyltrimethylammonium bromide (CTAB) cationic surfactant below the critical micelle formation concentration (CMC) values give a reduction and then an overcharging the CNT surface because of accumulation of the surfactant ions in the Stern layer. At concentrations above CMC the substantial drop in ζ-potential is observed. It is due to the shift of the shear plane toward solution as a result of formation of hemi-micelles on the surface. An increase in the mass ratio of artificial mineral Laponite (Lap) in suspension (X) from 0 to 0.4 results in a monotonic decrease of the ζ-potential of CNT + Lap hybrids with reaching its plateau value ≈ -32 mV at X ≥ 0.4 that corresponds to the ζ-potential of "pure" Lap platelets. This evidences the high surface coverage of nanotubes surface with Lap at X ≥ 0.4.The major methods to improve the dispersibility of carbon nanotubes, their colloidal stability and adsorptive properties are briefly discussed, namely: stabilization in mixtures of water and organic solvents; functionalization by chemical treatment; stabilization by additives of surfactants or polymers and hybridization by addition of supplementary stabilizing nanoparticles. CNTs can be significantly debundled in "good" solvents, such as 1cyclohexyl-2-pyrrolidone, N,N-dimethylformamide, or N-methyl-2-pyrrolidone. It is demonstrated that the dispersibility of CNTs is a complex function of the type of surfactant, its concentration and the surfactant/CNTs ratio. The optimum concentration of CTAB to achieve homogeneous aqueous dispersion of carbon nanotubes was identified to be near the CMC. Additions of CTAB significantly modify the size distribution of CNTs and a sharp transition from small primary aggregates to large secondary aggregates at concentrations above CMC is observed. At optimal concentration of Lap the nanotube particles get well stabilized, and a stepwise increase of sedimentation stability is observed.We have shown also that CNT + Lap hybrids can be effectively used for removal of methylene blue dye from aqueous systems. The kinetics and mechanisms of adsorption are elucidated.

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“…The functional groups also act as anchors in the synthesis of a newer class of nanocomposites with improved properties ,. The introduction of functional groups inclines the wettability towards polar compounds in some cases, for instance existence of the carboxylic group increases the hydrophilicity of the acid‐treated MWCNT ,. While in some cases it blocks the potential sorption sites, leading to a decline in sorption capacity and it was most prominent seen in the adsorption of organic chemicals like naphthalene .…”

Section: Functionalizationmentioning

confidence: 99%

Engineered Carbon Nanotubes: Review on the Role of Surface Chemistry, Mechanistic Features, and Toxicology in the Adsorptive Removal of Aquatic Pollutants.

et al. 2018

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The advent of nanotechnology has led to the development of new nanomaterials with enriched material properties over the conventional. These nanomaterials find wide application in numerous fields including environmental predominantly on water purification. Carbon nanotubes (CNT) are one among the nanomaterials widely employed for such application. Therefore, the present review emphasizes on the exceptional abilities of CNT especially in the removal of organics and inorganics from aquatic streams. Though numerous reviews were published in this subject most of them focused on the synthesis and specific applications. The authors learned that there is a wider gap on the review that presents the mechanistic features like the development of active sites, the effect of curvature, inclusion of heteroatoms, methods for the enhancement of affinity and selectivity through functionalization, the introduction of defects and the chemistry involved in their interaction with various category of pollutants. Hence, the present review delivers a clear understanding of the above-said factors in a comprehensive way. The article explicits on the various surface modification techniques (i.e covalent, non-covalent, defect and endohedral) along with their effects on the sorption efficiency. Further, the review also provides a clear picture of the toxicological aspects of the CNT. The authors strongly believe that the present review will aid in the understanding and design of multifunctional CNT towards environmental application in a comprehensive manner.

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Surface Modification Effects on CNTs Adsorption of Methylene Blue and Phenol

Cited by 59 publications

References 80 publications

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite

A short review on regulation of stability of aqueous suspensions of carbon nanotubes

Engineered Carbon Nanotubes: Review on the Role of Surface Chemistry, Mechanistic Features, and Toxicology in the Adsorptive Removal of Aquatic Pollutants.

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Surface Modification Effects on CNTs Adsorption of Methylene Blue and Phenol

Cited by 59 publications

References 80 publications

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe3C Nanocomposite

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe3C Nanocomposite

A short review on regulation of stability of aqueous suspensions of carbon nanotubes

Engineered Carbon Nanotubes: Review on the Role of Surface Chemistry, Mechanistic Features, and Toxicology in the Adsorptive Removal of Aquatic Pollutants.

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About

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite

Adsorption Kinetics of Acid Dye Acid Red 88 onto Magnetic Multi‐Walled Carbon Nanotubes‐Fe₃C Nanocomposite