Oxidation of Some Sustainable Sulfated Natural Polymers: Kinetics and Mechanism of Oxidation of Water-Soluble Chondroitin-4-Sulfate Polysaccharide by Hexachloroiridate(IV) in Aqueous Solutions

Hassan, Refat M.; Ibrahim, S. A.

doi:10.1021/acsomega.8b02184

Cited by 13 publications

(3 citation statements)

References 27 publications

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“…The free energy change (Δ G °), enthalpy change (Δ H °), and entropy change (Δ S °) are calculated thermodynamic parameters for NFD adsorption onto Az. These parameters were computed via the following formula: − Δ G ° = − 2.303 R T log K D where K D = q c / C e . Also Δ G ° = Δ H ° − T Δ S ° ln K D = Δ S ° R − Δ H ° R T where the value of C e is equilibrium NFD (mg L –1 ), R is the universal gas constant (8.314 J mol –1 K –1 ) and the value of q e is the NFD equilibrium concentration on Az (mg L –1 ).…”

Section: Resultsmentioning

confidence: 99%

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

Mohamed

Hassan

Ahmed

et al. 2023

Ind. Eng. Chem. Res.

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This work aims to study the removal of new fuchsin dye (NFD) using azithromycin (Az) by a spectrophotometric technique at two different wavelengths (547 and 286 nm), which formed the blend [Az+NFD]. Afterward, the [Az]TF, [NFD]TF, and nanoblend [Az+NFD]NB thin films were fabricated using the spin-coating technique. The models of Langmuir and Freundlich isotherms were applied to examine the experimental data of adsorption equilibrium and activation parameters. At 547 and 286 nm, the sorption capacity (q m) was determined to be 0.0095 and 0.01 mg g–1, correspondingly. The kinetic data showed that the reaction was fitted with a first-order reaction and the maximum adsorption capacity of Az at 547 nm was 0.0198 mg g–1 at 313 and 323 K, whereas at 286 nm, it was 0.0071 mg g–1 at 303 K. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) were calculated, and the experimental results showing negative values of ΔH° at 547 and 286 nm (−33.67 and −11.22 kJ mol–1, respectively) indicate the adsorption of NFD using Az is an exothermic reaction. The negative values of ΔG° at 547 and 286 nm (−19.67 and −13.01 kJ mol–1, respectively) indicate a spontaneous reaction. The calculated time-dependent density functional theory (TD-DFT) spectra matched the measured IR spectra precisely and corroborated the molecular structure of the tested materials. The experimental values and TD-DFT/CASTEP predictions for these properties are in great agreement. The optical (TD-DFT/CASTEP) characteristics of the [Az]Iso, [NFD]Iso, and [Az+NFD]NB gaseous phases are in close agreement with the experimental results. The greatest absorption bands for [Az]TF, [NFD]TF, and [Az+NFD]NB correspond to the π → π* electronic transition at 268, 547, and 625 nm, respectively, and the Gaussian program corresponds well with the experimental analysis for synthetic IR and molecular electrostatic potential. Optical illumination studies suggest that the nanoblend device films investigated may be employed in solar cell applications. The quantity of dye removed by Az decreases with an increase in the contact time and optimum adsorption was achieved in 4 min at 547 nm, whereas it increases with time at 286 nm and an optimum adsorption capacity was achieved in 6 min. The isolated molecule of [Az+NFD]Iso has a band gap of 2.415 eV, as determined by TD-DFT/DMol3. Thin films of thickness 100 ± 3 nm of [Az]TF, [NFD]TF, and [Az+NFD]NB via a spin-coating technique at room temperature were fabricated.

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Section: Resultsmentioning

confidence: 99%

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

Mohamed

Hassan

Ahmed

et al. 2023

Ind. Eng. Chem. Res.

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“…Many biological macromolecules tend to be readily soluble in aqueous solutions, in aqueous solutions of organic acids, and in other polar solvents, all of which can be suitable for electrospinning. [111,112] However, one frequently encountered difficulty is that the final electrospun fibers can be soluble in aqueous solutions at neutral pH, even if the starting materials were not originally soluble under these conditions. [113] This solubility makes them unsuitable for use in biological applications, where they will be exposed to cell culture media or biological fluids.…”

Section: Overcoming Aqueous Instability Of Biopolymersmentioning

confidence: 99%

Expanding the Repertoire of Electrospinning: New and Emerging Biopolymers, Techniques, and Applications

Madruga

Kipper

2021

Adv Healthcare Materials

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Electrospinning has emerged as a versatile and accessible technology for fabricating polymer fibers, particularly for biological applications. Natural polymers or biopolymers (including synthetically derivatized natural polymers) represent a promising alternative to synthetic polymers, as materials for electrospinning. Many biopolymers are obtained from abundant renewable sources, are biodegradable, and possess inherent biological functions. This review surveys recent literature reporting new fibers produced from emerging biopolymers, highlighting recent developments in the use of sulfated polymers (including carrageenans and glycosaminoglycans), tannin derivatives (condensed and hydrolyzed tannins, tannic acid), modified collagen, and extracellular matrix extracts. The proposed advantages of these biopolymer-based fibers, focusing on their biomedical applications, are also discussed to highlight the use of new and emerging biopolymers (or new modifications to well-established ones) to enhance or achieve new properties for electrospun fiber materials.

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“…Several types of research on the degradation of dyes by electrochemically advanced oxidation processes have been reported 17–18 . Because of their fairly low cost and high quality, these techniques seem to be useful in decontaminating textile wastewater without applying toxic chemical reagents to the solution to be treated 19,20 . Potassium permanganate is a potent oxidizing substance.…”

Section: Introductionmentioning

confidence: 99%

Oxidation process and kinetics of bromothymol blue by alkaline permanganate

Al‐Hossainy

Ibrahim

2020

Int J of Chemical Kinetics

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Spectrophotometric analysis was applied to check the kinetics of bromothymol blue (BTB) oxidation by alkaline permanganate at constant ionic strength 0.2 mol dm−3. The redox reaction was observed to proceed through two independently distinct, detectable steps. The first step coexists with the formation of intermediate complexes involving transient species relatively quickly of the blue hypomanganate(V) and green manganate(VI). The slowly decomposed intermediate formed to produce soluble colloidal manganese(IV) and the BTB keto‐derivatives as second slow‐stage oxidation products. The oxidation reaction demonstrated first‐order dependence in [MnO4−] and fractional first‐order kinetics at each of the BTB and alkali concentrations at an initial rapid stage for complexes formation. It was found that the oxidation process is of a base‐catalyzed nature. Novel spectrophotometric measurement of the blue hypomanganate(V) was introduced using a traditional spectrophotometer. An effective oxidation mechanism compatible with the kinetic data obtained in terms of the activation parameters assessed was analyzed, proposed, and discussed in line with the kinetic findings.

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Oxidation of Some Sustainable Sulfated Natural Polymers: Kinetics and Mechanism of Oxidation of Water-Soluble Chondroitin-4-Sulfate Polysaccharide by Hexachloroiridate(IV) in Aqueous Solutions

Cited by 13 publications

References 27 publications

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

Removal of Toxic Basic Fuchsin Dye from Liquids by Antibiotic Azithromycin Using Adsorption, TD-DFT Calculations, Kinetic, and Equilibrium Studies

Expanding the Repertoire of Electrospinning: New and Emerging Biopolymers, Techniques, and Applications

Oxidation process and kinetics of bromothymol blue by alkaline permanganate

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