“…The comparison of the results of pseudo-first and pseudo-second order models suggested that, although the sorption process is predominantly physical, the electronic be-havior of both hydrogel surface and dye molecules plays a crucial role in determining the sorbent/sorbate interactions. This can be attributed to the properties of carbon nanostructures and is consistent with literature data showing that pseudo-second order kinetics well described the adsorption of RD and MB dyes on graphene nanosheets and CNT, respectively [45,70]. A different behavior was obtained in the case of BR, where, although pseudo-second model kinetics possessed the higher R 2 values, the better fitting between q exp and q e (lower χ 2 values) was obtained for the pseudo-first order model, suggesting a lower involvement of electronic perturbation due to the absence of electrostatic charge on the dye molecule.…”
Section: Kinetic Data Analysissupporting
confidence: 91%
“…In our previous work, the ability of HG NT hybrid materials to modulate the release of ionic drugs upon application of an external electric field was evaluated and ascribed to the peculiar physic-chemical features of either MWCNT and Gel. Here, based on the scientific evidence reporting the applicability of hybrid materials with similar properties to environmental remediation [45,46], we aim to investigate a further extension of the applicability of such materials, exploiting their high affinity for dye adsorption from water solutions.…”
Section: Sorption Properties Of Hybrid Hydrogelsmentioning
confidence: 99%
“…Adsorption rate at 0 and 12 V conditions was also investigated in detail, showing that the concentration gradient at the sorbent/sorbate interface progressively hinders more of dye molecules to enter the adsorbent with time, thus resulting in fast adsorption at the first experimental times, followed by a slower rate eventually attaining equilibrium. At the first experimental time, a large number of empty sites were available for dyes adsorption, while the repulsive forces between the dye molecules on sorbent surface makes the remaining sites difficult to be occupied [45].…”
The performance of Carbon Nanotubes hybrid hydrogels for environmental remediation was investigated using Methylene Blue (MB), Rhodamine B (RD), and Bengal Rose (BR) as model contaminating dyes. An acrylate hydrogel network with incorporated CNT was synthesized by photo-polymerization without any preliminary derivatization of CNT surface. Thermodynamics, isothermal and kinetic studies showed favorable sorption processes with the application of an external 12 V electric field found to be able to influence the amount of adsorbed dyes: stronger interactions with cationic MB molecules (qexp and qexp12 of 19.72 and 33.45 mg g−1, respectively) and reduced affinity for anionic RD (qexp and qexp12 of 28.93 and 13.06 mg g−1, respectively) and neutral BR (qexp and qexp12 of 36.75 and 15.85 mg g−1, respectively) molecules were recorded. The influence of pH variation on dyes adsorption was finally highlighted by reusability studies, with the negligible variation of adsorption capacity after five repeated sorption cycles claiming for the suitability of the proposed systems as effective sorbent for wastewater treatment.
“…The comparison of the results of pseudo-first and pseudo-second order models suggested that, although the sorption process is predominantly physical, the electronic be-havior of both hydrogel surface and dye molecules plays a crucial role in determining the sorbent/sorbate interactions. This can be attributed to the properties of carbon nanostructures and is consistent with literature data showing that pseudo-second order kinetics well described the adsorption of RD and MB dyes on graphene nanosheets and CNT, respectively [45,70]. A different behavior was obtained in the case of BR, where, although pseudo-second model kinetics possessed the higher R 2 values, the better fitting between q exp and q e (lower χ 2 values) was obtained for the pseudo-first order model, suggesting a lower involvement of electronic perturbation due to the absence of electrostatic charge on the dye molecule.…”
Section: Kinetic Data Analysissupporting
confidence: 91%
“…In our previous work, the ability of HG NT hybrid materials to modulate the release of ionic drugs upon application of an external electric field was evaluated and ascribed to the peculiar physic-chemical features of either MWCNT and Gel. Here, based on the scientific evidence reporting the applicability of hybrid materials with similar properties to environmental remediation [45,46], we aim to investigate a further extension of the applicability of such materials, exploiting their high affinity for dye adsorption from water solutions.…”
Section: Sorption Properties Of Hybrid Hydrogelsmentioning
confidence: 99%
“…Adsorption rate at 0 and 12 V conditions was also investigated in detail, showing that the concentration gradient at the sorbent/sorbate interface progressively hinders more of dye molecules to enter the adsorbent with time, thus resulting in fast adsorption at the first experimental times, followed by a slower rate eventually attaining equilibrium. At the first experimental time, a large number of empty sites were available for dyes adsorption, while the repulsive forces between the dye molecules on sorbent surface makes the remaining sites difficult to be occupied [45].…”
The performance of Carbon Nanotubes hybrid hydrogels for environmental remediation was investigated using Methylene Blue (MB), Rhodamine B (RD), and Bengal Rose (BR) as model contaminating dyes. An acrylate hydrogel network with incorporated CNT was synthesized by photo-polymerization without any preliminary derivatization of CNT surface. Thermodynamics, isothermal and kinetic studies showed favorable sorption processes with the application of an external 12 V electric field found to be able to influence the amount of adsorbed dyes: stronger interactions with cationic MB molecules (qexp and qexp12 of 19.72 and 33.45 mg g−1, respectively) and reduced affinity for anionic RD (qexp and qexp12 of 28.93 and 13.06 mg g−1, respectively) and neutral BR (qexp and qexp12 of 36.75 and 15.85 mg g−1, respectively) molecules were recorded. The influence of pH variation on dyes adsorption was finally highlighted by reusability studies, with the negligible variation of adsorption capacity after five repeated sorption cycles claiming for the suitability of the proposed systems as effective sorbent for wastewater treatment.
“…In last decade, engineered hydrogels have emerged as an effective adsorbent for removal of a wide range of dyes from wastewater [20,28]. Some recent examples that utilize engineering materials such as graphene [29], carbon nanotubes [30,31], activated charcoal [32], and other surface-treated materials [33] in hydrogels for improvements in strength but at the expense of economic and/or environmental cost. Recently, a significant amount of attention in biopolymer derived materials in adsorbent hydrogels has provided improved sustainability and excellent performance with a low carbon footprint [34].…”
Removal of dyes through adsorption from wastewater has gained substantial interest in recent years, especially in development of hydrogel based adsorbents, owing to their easy use and economical nature. The aim of the present study was to design a super-adsorbent hydrogel based on sodium styrenesulfonate (NaSS) monomer for removal of dyes like methylene blue (MB). NaSS displays both an aromatic ring and strongly ionic group in its monomer structure that can enhance adsorption capacity. Poly(sodium styrenesulfonate-co-dimethylacrylamide) hydrogels were prepared by solution free radical polymerization using gelatin methacryloyl (GelMA) as crosslinker, creating a highly porous, three-dimensionally crosslinked polymer network contributing to higher swelling ratios of up to 27,500%. These super-adsorbent hydrogels exhibited high adsorption capacity of 1270 mg/g for MB adsorption with above 98% removal efficiency. This is the first report for such a high adsorption capacity for dye absorbance for NaSS-based hydrogels. Additionally, the adsorption kinetics using a pseudo-first-order and the Freundlich adsorption isotherm models for multilayer, heterogeneous adsorption processes has been reported. The adsorbents’ reusability was confirmed through 4 repeated cycles of desorption-adsorption. The results discussed herein illustrate that NaSS based chemistries can be used as an efficient option for removal of organic dyes from contaminated wastewater.
“…Carbon dots (CDs) and magnesium fluorohydroxyapatite (MFA) were utilized to functionalize carbon nanotubes (f-CNTs) to create a unique f-CNT-CD-MFA hybrid, as previously described. Because of its superior physicochemical and adsorption capabilities, the hybrid was introduced into the alginate matrix [ 112 ]. Good interfacial attachment between the filler and matrix was achieved by the application of sonication waves, which also contributed to an increase in the heat resistance of pure alginate as a result of this rapid and environmentally friendly approach to preparation.…”
Section: Fabrication Techniques Of Carbon Dots Reinforced Hydrogelsmentioning
Hydrogels have emerged as important soft materials with numerous applications in fields including biomedicine, biomimetic smart materials, and electrochemistry. Because of their outstanding photo-physical properties and prolonged colloidal stability, the serendipitous findings of carbon quantum dots (CQDs) have introduced a new topic of investigation for materials scientists. CQDs confined polymeric hydrogel nanocomposites have emerged as novel materials with integrated properties of the individual constituents, resulting in vital uses in the realm of soft nanomaterials. Immobilizing CQDs within hydrogels has been shown to be a smart tactic for preventing the aggregation-caused quenching effect and also for manipulating the characteristics of hydrogels and introducing new properties. The combination of these two very different types of materials results in not only structural diversity but also significant improvements in many property aspects, leading to novel multifunctional materials. This review covers the synthesis of doped CQDs, different fabrication techniques for nanostructured materials made of CQDs and polymers, as well as their applications in sustained drug delivery. Finally, a brief overview of the present market and future perspectives are discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.