scholarly journals A Comparative Analysis of the Global Electrophilicity Power of Some Cationic Dyes. Understanding Selective Removal Dyes From Mixture Solution

2021 ◽  
Vol 10 (4) ◽  
pp. 2933-2944
Keyword(s):  
Dft Calculations ◽  
Cationic Dyes ◽  
Anionic Sites ◽  
Electrophilicity Index ◽  
Fukui Functions ◽  
Reactive Adsorption ◽  
Adsorption Sites ◽  
Adsorbent Surface ◽  
Dyes Adsorption ◽  
Mixture State

Some bibliographic findings of dyes' adsorption from a mixture state suggest that certain dyes are more likely to be adsorbed first on the adsorbent surface than others, and therefore attracted strongly to the adsorbent surface. To explain the phenomenon, DFT calculations are applied. In this fact, the global electrophilicity index ω of some cationic dyes has been evaluated. The results show that, for studied electrophilic dyes, the molecule with the greatest global electrophilicity power is favored to be adsorbed on the surface's anionic sites. In addition, local electrophilic Parr and Fukui functions were introduced to characterize the most reactive adsorption sites properly and indicate successfully the same adsorption centers. The success of DFT calculations in explaining and predicting the selective dye was assessed.

Removal of Dyes from Aqueous Solutions by Adsorption on Chrome-Tanned Solid Wastes Generated in the Leather Industry

2003 ◽  
Vol 38 (2) ◽  
pp. 393-411 ◽  
Author(s):  
Soufiane Tahiri ◽  
Ali Messaoudi ◽  
Abderrahman Albizane ◽  
Mohamed Azzi ◽  
Mohamed Bouhria ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Operating Conditions ◽  
Solid Wastes ◽  
Cationic Dyes ◽  
Optimum Operating ◽  
Leather Industry ◽  
Anionic Dyes ◽  
Ph Values ◽  
Acidic Conditions ◽  
Dyes Adsorption

Abstract In this work, the ability of chrome shavings and of crust leather buffing dusts to remove dyes from aqueous solutions has been studied. Buffing dusts proved to be a much better adsorbent than chrome shavings for cationic dyes. The adsorption of anionic dyes is very important on two studied wastes. The pH has an obvious influence on the adsorption of dyes. Adsorption of cationic dyes is less favourable under acidic conditions (pH <3.5) and at high pH values (pH >10.5). The adsorption of anionic dyes on both adsorbents is more favourable under acidic conditions (pH <3). The adsorption on chrome shavings is improved by the use of finer particles. The kinetic adsorption was also studied. Adsorption isotherms, at the optimum operating conditions, were determined. Adsorption follows the Langmuir model. The isotherm parameters have been calculated. The column technique could be applied to treat significant volumes of solutions.

Scalable Sulfonate-Coated Cotton Fibers as Facile Recyclable and Biodegradable Adsorbents for Highly Efficient Removal of Cationic Dyes

2021 ◽  
Author(s):  
Linhua Li ◽  
Baojie Dou ◽  
Jianwu Lan ◽  
Jiaojiao Shang ◽  
Yafang Wang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Large Scale ◽  
Ph Value ◽  
Cationic Dyes ◽  
Cotton Fibers ◽  
Wastewater Remediation ◽  
Efficient Removal ◽  
Adsorption Sites ◽  
Highly Efficient ◽  
Coated Cotton

Abstract Adsorbents with superior adsorption capacity and facile recyclability are viewed as promising materials for dye wastewater treatment. In this work, a novel sulfonate decorated cotton fiber as a biodegradable and recyclable adsorbent was fabricated for highly efficient removal of cationic dyes. Herein, the poly(sodium p-styrenesulfonate-co-N-methylol acrylamide) (P(SSNa-co-NMAM)) with SSNa units as adsorption sites and NMAM units as thermal-crosslinking points was synthesized for modification of cotton fibers in a large scale at high temperature (160 oC). The various characterization investigations confirmed the successful construction of the P(SSNa-co-NMAM) coated cotton fibers (PCF). As expected, the as-obtained adsorbent presented outstanding adsorption performance toward cationic dyes in the both static and dynamic states, even in the synthetic effluent. The adsorption processes of cationic dyes onto the PCF were well fitted by the Langmuir isotherm model and Pseudo-second-order kinetics, respectively. The thermodynamics study showed that the adsorption reaction of the cationic dyes onto PCF was a spontaneous and endothermic process. The maximum adsorption capacities of PCF toward MEB, RhB and MG were 3976.10, 2879.80 and 3071.55 mg/g, respectively. The responsible adsorption of dyes ontothe PCF was electrostatic interaction. Moreover, the adsorption capacity of PCF toward cationic dyes was slight influenced by pH value of solution, because of the stable feature of sulfonate moiety in acid and alkali. In addition, the as-prepared PCF exhibited satisfactory recyclability and reusability. Given the aforementioned results, the as-obtained PCF is a promising adsorbent with great potential for practical application in the dye-contaminated wastewater remediation.

Synthesis and characterization of a novel amphoteric adsorbent coating for anionic and cationic dyes adsorption: Experimental investigation and statistical physics modelling

2018 ◽  
Vol 351 ◽  
pp. 221-229 ◽  
Author(s):  
Syahida Farhan Azha ◽  
Lotfi Sellaoui ◽  
Muhamad Sharafee Shamsudin ◽  
Suzylawati Ismail ◽  
Adrián Bonilla-Petriciolet ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Statistical Physics ◽  
Cationic Dyes ◽  
Synthesis And Characterization ◽  
Dyes Adsorption

One-step synthesis of Cu(II) metal–organic gel as recyclable material for rapid, efficient and size selective cationic dyes adsorption

2019 ◽  
Vol 86 ◽  
pp. 203-212 ◽  
Author(s):  
Qing Wu ◽  
Li He ◽  
Zhong Wei Jiang ◽  
Yang Li ◽  
Ting Ting Zhao ◽  
...  
Keyword(s):  
Cationic Dyes ◽  
Metal Organic ◽  
One Step ◽  
Dyes Adsorption ◽  
Organic Gel

scholarly journals The dynamics of benzene on Cu(111): a combined helium spin echo and dispersion-corrected DFT study into the diffusion of physisorbed aromatics on metal surfaces

2017 ◽  
Vol 204 ◽  
pp. 471-485 ◽  
Author(s):  
M. Sacchi ◽  
P. Singh ◽  
D. M. Chisnall ◽  
D. J. Ward ◽  
A. P. Jardine ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Spin Echo ◽  
Metallic Surface ◽  
Bravais Lattice ◽  
Binding Interaction ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Lattice Density ◽  
Shed Light

We use helium spin-echo spectroscopy (HeSE) to investigate the dynamics of the diffusion of benzene adsorbed on Cu(111). The results of these measurements show that benzene moves on the surface through an activated jump-diffusion process between the adsorption sites on a Bravais lattice. Density Functional Theory (DFT) calculations with van der Waals (vdW) corrections help us understand that the molecule diffuses by jumping through non-degenerate hollow sites. The results of the calculations shed light on the nature of the binding interaction between this prototypical aromatic molecule and the metallic surface. The highly accurate HeSE experimental data provide a quantitatively stringent benchmark for the vdW correction schemes applied to the DFT calculations and we compare the performances of several dispersion interaction schemes.

Theoretical study of 11-thiocyanatoundecanoic acid phenylamide derivatives on corrosion inhibition efficiencies

2014 ◽  
Vol 92 (9) ◽  
pp. 876-887 ◽  
Author(s):  
Seda Sagdinc ◽  
Yesim Kara ◽  
Filiz Kayadibi
Keyword(s):  
Density Functional ◽  
Corrosion Inhibitors ◽  
Energy Gap ◽  
Basis Set ◽  
Inhibitor Molecule ◽  
Functional Theory ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Hartree Fock ◽  
Adsorption Sites

Ab initio Hartree–Fock (HF) and Density Functional Theory (DFT) B3LYP methods with the 6-311G(d,p) basis set were applied to the three 11-thiocyanatoundecanoic acid phenylamide derivatives as corrosion inhibitors. Inhibition efficiency obtained experimentally followed the following order: N-(4-methoxyphenyl)-11-thiocyanatoundecanamide (N3MPTUA) > N-phenyl-11-thiocyanatoundecanamide (NPTUA) > N-(3-nitrophenyl)-11-thiocyanatoundecanamide (N3NPTUA). The molecular parameters most relevant to their potential action as corrosion inhibitors have been calculated in the neutral and protonated forms: EHOMO, ELUMO, energy gap (ΔE), dipole moment (μD), electronegativity (χ), global hardness (η), and the fraction of electrons transferred from the inhibitor molecule to the metallic atom (ΔN). The results of most of the global reactivity descriptors show that the experimental and theoretical studies agree well, and confirm that N3MPTUA is a better inhibitor than NPTUA or N3NPTUA. In addition, the local reactivity, analyzed through Fukui functions, show that the oxygen and nitrogen atoms will be the main adsorption sites.

Ti-coated BC2N nanotubes as hydrogen storage materials

2013 ◽  
Vol 91 (7) ◽  
pp. 598-604 ◽  
Author(s):  
Seifollah Jalili ◽  
Farzad Molani ◽  
Jeremy Schofield
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Molecular Form ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Bc2n Nanotubes

Density functional theory (DFT) calculations have been performed to investigate Ti adsorption on BC2N nanotubes and the hydrogen adsorption capacity of Ti-coated structures. Different adsorption sites have been examined for the Ti adatom, and it is found that the most stable structure has a configuration with alternating columns of carbon and boron–nitrogen hexagons. The DFT calculations indicate that an adsorbed Ti atom on a carbon hexagon can bind four hydrogen molecules in molecular form, while Ti atoms on boron–nitride hexagons can adsorb three hydrogen molecules and two hydrogen atoms. Based on the calculations, the gravimetric efficiency corresponding to decoration of 67% of six carbon rings with Ti adatoms is estimated to be 8 wt %. Computation of the charge transfer reveals that the Ti atom on BC2N is in a cationic state. In addition, Ti adsorption has a significant influence on the electronic structure of the nanotubes and allows for the conversion of nanotubes from semiconductors in the pristine state to conductors upon doping. The interactions between the nanotubes, the Ti atom and hydrogen molecules have also been analyzed using Dewar coordination and Kubas interactions.

scholarly journals DFT Calculations and Molecular Docking Studies on a Chromene Derivative

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Najet Aouled Dlala ◽  
Younes Bouazizi ◽  
Houcine Ghalla ◽  
Naceur Hamdi
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Noncovalent Interactions ◽  
Chemical Shifts ◽  
Molecular Geometry ◽  
Docking Studies ◽  
Fukui Functions ◽  
Td Dft ◽  
Molecular Electrostatic Potential Surface ◽  
Reduced Density

Chromenes and their derivatives have been considered as an important class of oxygen-containing heterocycles. There has been an increasing interest in the study of chromenes due to their biological activity. Herein, the structural, electronic, and vibrational properties of a chromene derivative, entitled 2‐amino‐5‐oxo‐4‐phenyl‐4,5‐dihydropyrano[3,2‐c]chromene‐3‐carbonitrile and abbreviated as Chrom-D, have been reported. The FT-IR, UV-vis, and 1H-NMR and 13C-NMR chemical shifts’ measurements were recorded. The molecular geometry and the vibrational frequencies are computed in the frame of density functional theory at the B3LYP/6-311++G(d,p) level of theory. The noncovalent interactions in the crystal lattice which are responsible to the 3D crystal structure of Chrom-D are investigated based on Hirshfeld surfaces and topological reduced density gradient (RDG) analysis. Molecular electrostatic potential surface, Mulliken charges, and Fukui functions are computed in order to find out the electrophilic and nucleophilic sites. The electronic properties of the title compound have been studied based on the TD-DFT calculations. Finally, Chrom-D has been evaluated as a multifunctional agent against Alzheimer’s disease (AD).

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