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A thixotropy test on graphene-G at 4 wt% of the gelator and 0.2 wt% of the nanomaterial. G′ and G′′ as a function of time and application of low (G′ > G′′ regimes, γ = 0.025%) and destructive strains (G′′ > G′ regimes, γ = 40%) at 25 °C.
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Due to large drug consumption, pharmaceutically active compounds (PhACs) can be found as water contaminants. The removal of PhACs is a significant issue, as they can easily overtake traditional purification methods. Because of their surface properties, carbon nanomaterials are among the most efficient materials able to adsorb PhACs. However, their...
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... percentage of strain recovery was evaluated through a comparison of the initial value of G with the one obtained in the LVR after disruption (Figure 3; Table S2). The data collected show that graphene-G exhibited a better self-healing ability than CNT-G, as higher percentages of recovery were calculated both in the first and the second cycles (13% and 9% for CNT-G and 32% and 100% for graphene-G, respectively). ...
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... we took into consideration CNT-G and graphene-G and measured the evolution of moduli at low (G′ > G′′ regimes, γ = 0.025%) and destructive (G′′ > G′ regimes, γ = 40%) strains. The percentage of strain recovery was evaluated through a comparison of the initial value of G′ with the one obtained in the LVR after disruption (Figure 3; Table S2). The data collected show that graphene-G exhibited a better self-healing ability than CNT-G, as higher percentages of recovery were calculated both in the first and the second cycles (13% and 9% for CNT-G and 32% and 100% for graphene-G, respectively). ...
Citations
... Generally, the performance of this gel is influenced by the strength of the colloidal force. The gel with the weaker colloidal force is the best system for adsorption (Rizzo et al., 2019). DNA-chitosan (DNA-CS) hydrogel is another material that was used for the removal of pharmaceuticals from water. ...
In this work, we screened several surfactants for their ability to harden Eutectic Mixtures. We found cetyldiethanolamine-N-oxide as the best candidate, which was able to form eutectogel in four eutectic mixtures. Characterization of the gels obtained in terms of thermal stability, rheology and gelation kinetics, showed a prominent influence of the nature of the hydrogen bonding accepting and donating components for the first two parameter and the other one, respectively. Then, we assessed the eutectogels for their ability to adsorb I2, as a model for its radioactive nuclides, from apolar solvent solutions. The best performing gel allowed fast and thorough removal of I2, over a broad range of initial concentrations. This gel displayed a maximum adsorption capacity of 280 mg/g, competitive with most gel-based sorbent reported in the literature for the adsorption of iodine. Interestingly, the eutectogel proved to be highly recyclable, it could be regenerated and reused without loss in performance.
Desulfurization of fuel, that avoids the introduction in the atmosphere of toxic sulfur volatile compounds, usually formed during combustion, is a viable strategy to reduce pollution. To find new efficient...
Green nanoemulsions (NE) composed of water/ethanol/triton X100/capmul MCM C8 (CMC8) were prepared to eliminate ciprofloxacin (CIP) from an aqueous system. These NE were prepared by titration process followed by constructing various phase diagrams. From them, five NE1-NE5 were identified as the most optimum for the purpose. These five were evaluated for globule size, size distribution (polydispersity index, PDI), viscosity, zeta potential and refractive index (RI) and thermodynamic stability. Percent removal efficiency (% RE) studies of NE1- NE5 formulations were studied at 10 min, 15 min, and 30 min. Compositions were selected due to maximum solubility of CIP and NE1-NE5 were identified with the maximum area delineated in pseudo ternary phase diagrams. The optimized and selected NE5 exhibited the lowest globule size (41± 3 nm), least PDI (0.12), optimal zeta potential (-22.9 mV), and the highest value of % RE (∼ 95%). The robust NE5 revealed optimum viscosity (98.8 ±2.5 cP) and spherical globular shape (fold error = 1.35) distributed homogeneously throughout the bulk. There was significant impact of water and CMC8 contents on the viscosity (η), size and RI. The %RE (liquid-liquid adsorption efficiency) of CIP from an aqueous bulk solution was significantly affected with the concentration of CMC8 and water content, viscosity, and size of CNE. UV scanning and IR studies confirmed absence of CIP in treated water. Hence, results dictated that NE5 can be a suitable approach to remove CIP from aquatic system contaminated through several effluent sources.
Benzimidazole dicationic ionic liquids (BDILs) have not yet been widely explored in spite 12 of their potential. Therefore, two structurally related families of BDILs, paired with either bromide 13 or bistriflimide anions and bearing alkyl spacers ranging from C3 to C6, have been prepared. Their 14 thermal properties have been studied by thermogravimetric analysis (TGA) and differential scan-15 ning calorimetry (DSC), while their electrical properties have been assessed by cyclic voltammetry 16 (CV). TG analysis confirmed the higher stability of the bistriflimide BDILs over the bromide BDILs, 17 with minor variation within the two families. Conversely, DSC and CV allowed for ascertaining the 18 role played by the spacer length. In particular, the thermal behavior changed dramatically among 19 the members of the bistriflimide family, and all three possible thermal behavior types of ILs were 20 observed. Furthermore, cyclic voltammetry showed different electrochemical window ([C3(C1Ben-21 zIm)2][Tf2N]2 < [C4(C1BenzIm)2][Tf2N]2, [C5(C1BenzIm)2][Tf2N]2 < [C6(C1BenzIm)2][Tf2N]2) as well as 22 a reduction peak potential, shape and intensity as a function of the spacer length. The results ob-23 tained highlight the benefit of accessing a more structurally diverse pool of compounds offered by 24 dicationic ILs when compared to the parent monocationic ILs. In particular, gains are to be found 25 in the ease of fine-tuning their properties, which translates in facilitating further investigations to-26 wards BDILs as designer solvents and catalysts. 27 Keywords: ionic liquids; green solvents; benzimidazole; dicationic ionic liquids, thermal stability, 28 thermal behavior, cyclic voltammetry 29 30
Nalidixic acid is the first antimicrobial quinolone and today extensively applied in human and veterinary medicine. Recently, it is detected in the surface waters and is on the rise. In this study, the renewable adsorbent based on Graphene oxide (i.e. NiZrAl-layered double hydroxide-graphene oxide-chitosan (NiZrAl-LDH-GO-CS NC)), was synthesized and employed effectively for the adsorptive removal of Nalidixic acid (NA). The successful synthesis of the nanocomposite was evaluated using Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX), X-ray powder diffraction (XRD), RAMAN spectroscopy, pHZPC and Barrett-Joyner-Halenda (BJH)/ Brunauer–Emmett–Teller (BET) analyses. The NiZrAl-LDH-GO-CS NC presented fast adsorption rates towards NA and maximum adsorption capacity on the basis of the pseudo-second-order (PSO) kinetic model reached 277.79 mg g⁻¹, much higher than those reported by different nano-based adsorbents. The adsorption process was examined using the central composite design (CCD), adaptive network-based fuzzy inference system (ANFIS), and general regression neural network (GRNN) under various operational conditions of adsorbent dose, initial NA concentration, pH, temperature, and time. The comparison of the models revealed that ANFIS model outperformed compared to the others, with R² = 0.9997, MSE=0.0004, RMSE = 0.0082, and MAE = 0.0068, demonstrating that ANFIS is a powerful methodology for modeling NA adsorption by NiZrAl-LDH-GO-CS nanocomposite.
Moreover, to express the most applicable conditions, RSM-GA and RSM-DFA based optimization is implemented and verified in practice (more than %92 NA removal is achieved). Further thermodynamic and kinetic assessments both signify the chemisorption mechanisms in this adsorption system. To sum up, LDH-GO-CS as a renewable adsorbent, will possibly have noteworthy effects on pharmaceutical wastewater remediation and can be considered for advanced researches as an efficient reagent for practicable remediation techniques.
In this study, the adsorption of ciprofloxacin was reviewed from aqueous media (water and wastewater) in studies published over the last years (1990-2020). The objective of this research was to analyze ciprofloxacin removal from aqueous media by adsorption process through a systematic review and meta-analysis. It was found that the ciprofloxacin adsorption data were well fitted on the Langmuir isotherm and the pseudo-second-order kinetic models. The review further showed that the optimum pH ranged from 6 to 8.5 in most articles. Based on the reported results, the temperature and standard enthalpy change (ΔH°) varied in the range of 273-388 K and-1,212.6 to 170.21 kJ/mol, respectively. The maximum reported adsorption capacity for ciprofloxacin was 1,575 mg/g for C@silica core/shell nanoparticles. Also, the minimum adsorption capacity was related to birnessite (47 ng/g). The most effective adsorbent for ciprofloxacin removal was C@sil-ica core/shell nanoparticles from ZIF-8. The results of the meta-analysis revealed that the adsorp-tion process could remove ciprofloxacin with an acceptable mean efficiency of 59.32% (95% CI: 44.66-73.97). It can be suggested to apply the novel hybrid processes, adsorbent modification, composite adsorbent development, neural network modeling to increase ciprofloxacin adsorption.
