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a HEC-EDTA synthesis reaction scheme and b Degree of swelling against immersion time of EDTA crosslinked HEC hydrogel
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In this paper, a new green pH-sensitive EDTA crosslinked HEC (cellulose-based hydrogel (swelling rate ~ 1005%)) adsorbent was successfully elaborated. The synthesis of HEC-EDTA at the high advanced crosslinking degree (up to 92%), was carried out using DAEDT and DMAP as acyl transfer agent, where the lamellar morphology (2D-microstructure) was high...
Citations
... This process involved a homogeneous reaction facilitated by the use of 4-Dimethylamino pyridine (DMAP) as a catalyst. The reaction led to the formation of diester and monoester linkages, resulting in a modified version of HEC known as HECD (Jabir et al., 2022;Zannagui et al., 2020). (Jabir et al., 2022) Oxidation Oxidation of HEC involves introducing oxidizing agents to modify its chemical structure, which improves its properties for various applications. ...
... The reaction led to the formation of diester and monoester linkages, resulting in a modified version of HEC known as HECD (Jabir et al., 2022;Zannagui et al., 2020). (Jabir et al., 2022) Oxidation Oxidation of HEC involves introducing oxidizing agents to modify its chemical structure, which improves its properties for various applications. Commonly used oxidizing agents include hydrogen peroxide (Finnegan et al., 2010;Gustafsson, Hrycay, & Ernster, 1976), and potassium persulfate (Pang & Fiume, 2001). ...
... The molecular dynamics simulations conducted in the study support these findings, revealing that the adsorption process is facilitated by the formation of regioselective clusters around the EDTA carboxylates, enhancing the overall adsorption efficiency. Overall, the unique properties of HEC-EDTA make it a promising candidate for the effective removal of methylene blue from wastewater, contributing to improved water treatment solutions (Jabir et al., 2022). Figure 10. ...
Hydroxyethylcellulose (HEC) is a water-soluble derivative of cellulose, obtained by reacting cellulose with ethylene oxide. This chemical transformation imparts distinctive characteristics to HEC, such as enhanced water solubility, increased viscosity, and optimized stability under various pH and thermal conditions. These properties make HEC an essential polymer in various industrial sectors. In the cosmetic and pharmaceutical industries, HEC is mainly used for its thickening, stabilizing, and moisturizing properties. It is also employed in the paint and coatings sector as a viscosity modifier, and in the food industry for its emulsifying and stabilizing functions. Additionally, cellulose is used in water treatment processes. Chemical modifications of HEC, such as the control of substitution degree and crosslinking, enable its properties to be tailored for specific applications. The methods of HEC modification, its physical and chemical properties, and its numerous industrial applications are examined in this article, emphasizing its versatility and advantages over pure cellulose.
... pH-responsive hydrogel offers a larger surface area during swelling. This allows more contaminated solutions to come into contact with the hydrogel, improving pollutant removal efficiency (Jabir et al., 2022). For example, Wang et al. developed a pH-responsive carboxymethyl cellulose/chitosan hydrogel for adsorbing and desorbing anionic and cationic dyes. ...
... The hydrogel exhibited reusability for up to seven cycles with very minimal loss of adsorption capacity (Singh et al., 2019). Jabir et al. demonstrated impressive dye removal with cellulose-based hydrogel (Jabir et al., 2022). These studies underscore the effectiveness of pH-responsive hydrogel, enabling efficient desorption of pollutants and hydrogel regeneration for multiple uses (Li et al., 2023). ...
... To enhance the adsorption efficiency, chelating functional groups can be grafted onto the surface of the adsorbent (Li et al. 2009;Pourjavadi et al. 2009;Zhao et al. 2019). Several studies have shown that HEC functionalized with organic compounds and polymers like Ethylenediaminetetraacetic acid (EDTA) and poly (acrylic acid) (PAA) can significantly increase the elimination capacity of valuable metal ions (Cavus et al. 2006;Jilal et al. 2018Jilal et al. , 2019Jabir et al. 2022). However, certain properties need to be fine-tuned to optimize the adsorbing properties of modified HEC. ...
... Recently, numerous studies have aimed to mitigate the ecological impacts of water pollution by utilizing biodegradable materials for adsorption (Jabir et al. 2022;Al-Gethami et al. 2024). Pollution from heavy metals and industrial dyes is particularly concerning due to their high toxicity and persistence in the environment. ...
This study focuses on the development of eco-friendly biobased adsorbents through a sustainable hydrothermal and freeze-drying synthesis process, utilizing cost-effective bio-sourced materials to minimize energy consumption and waste. The biobased adsorbents were elaborated using hydroxyethyl cellulose-ionic liquids and bentonite clay. The elaborated biocomposites were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy/attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA), and electron microscopy-energy dispersive X-ray (SEM–EDX), Brunauer–Emmett–Teller (BET) and zeta potential (ZP). Structural analysis confirms the intercalation and incorporation of HEC-ILs polymeric chains into Be-Na matrix and the formation of biocomposites. The [HEC-ILs/Be-Na] composite was subsequently employed for solid-phase extraction of Co(II) by investigating the effect of pH, initial Co(II) concentrations, time, temperature, and the presence of co-existing ions (Na(I), Li(I), Mn(II), Ni(II), and Al(III)). The adsorption kinetics of Co(II) metal ions were suitably characterized using the pseudo-second-order model (with R² > 0.99). Furthermore, the adsorption isotherms conformed to the Langmuir model (with R² > 0.97), suggesting a chemisorption process with an adsorption capacity of 69.8 mg/g. The thermodynamic study reveals that the adsorption process exhibits characteristics of spontaneity and endothermicity (ΔH° = 74.197 kJ mol⁻¹, ΔG° < 0 kJ mol⁻¹). The proposed mechanism for Co(II) adsorption on the developed biocomposite involves electrostatic interactions, ion exchange, and anion-π interactions. The biobased composite exhibited remarkable selectivity for Co(II) and demonstrated great potential as an adsorbent for industrial applications.
Graphical abstract
... To overcome the resistance to the transfer of mass of MB between the liquid and solid phases, the initial concentration of MB provided the necessary mortice force (Jabir et al., 2022;Haydari et al., 2022). Figure 9 presents the variation of the adsorbed quantity with the dye's starting concentration for HApS220 (a) and HApS230 (b). ...
... In fact, it has been reported that nano-hydroxyapatite exhibits rapid elimination efficiency for all MB concentrations which is important for wastewater treatment application (Swamiappan et al., 2021). Moreover, the lack of internal diffusion resistance may be responsible for the high rate of adsorption (Jabir et al., 2022). Various starting MB concentrations were tested for their effects on adsorption equilibrium time, and the results indicated that these initial MB concentrations had little to no impact on this time. ...
... [2][3][4] However, because of its high melting point ''degrades before melting'', 5 cellulose cannot be used in preparing formulations based on thermal processes, which constitute an essential part of industrial processes. 6 Therefore, chemical derivatization is an effective way to increase the economic and industrial value of this valuable renewable resource providing fibers, films, food packaging, membranes, sponges, etc. [7][8][9] The homogenous functionalization of cellulose provides reasonable control of the polydispersity and the physicochemical properties of polymeric systems, and this can only be achieved through a good understanding of the solubility phenomenon of cellulose, especially the supramolecular interactions. Cellulose dissolution is a highly complicated mechanism, where the hydrophobic and the hydrophilic sites are dispersed in the cellulose structure simultaneously, 10,11 generated by the intra and intermolecular H-bond interactions. ...
In this paper, a benzyltriethylammonium/urea DES was investigated as a new green and eco-friendly medium for the progress of organic chemical reactions, particularly the dissolution and the functionalization of cellulose. In this regard, the viscosity-average molecular weight of cellulose (M̄w) during the dissolution/regeneration process was investigated, showing no significant degradation of the polymer chains. Moreover, X-ray diffraction patterns indicated that the cellulose dissolution process in the BTEAB/urea DES decreased the crystallinity index from 87% to 75%, and there was no effect on type I cellulose polymorphism. However, a drastic impact of the cosolvents (water and DMSO) on the melting point of the DES was observed. Besides, to understand the evolution of cellulose-DES interactions, the formation mechanism of the system was studied in terms of H-bond density and radial distribution function (RDF) using molecular dynamics modeling. Furthermore, density functional theory (DFT) was used to evaluate the topological characteristics of the polymeric system such as potential energy density (PED), laplacian electron density (LED), energy density, and kinetic energy density (KED) at bond critical points (BCPs) between the cellulose and the DES. The quantum theory of atoms in molecules (AIM), Bader's quantum theory (BQT), and reduced density gradient (RDG) scatter plots have been exploited to estimate and locate non-covalent interactions (NCIs). The results revealed that the dissolution process is attributed to the physical interactions, mainly the strong H-bond interactions.
... Thus, when low power solution-state 1 H decoupling is applied, it is efficient in decoupling the signals from the solution-state (i.e., narrowed by tumbling) but inefficient in decoupling signals from solids, leading to a strong bias towards the solution-state. Such editing is very well documented in the literature and is central to both CMP-NMR [1] and CLASSIC NMR [2] which can be used to understand a range of processes including; crystallization reactions, [3,4] swelling (e.g., rubber degradation in automobiles from biodiesel, [5] hydrogel swelling for uptake/release of compounds), [6,7] structure [8] and interactions in soil, [9] biofuel production [10] and even to study living organisms. [11,12] However, the limitation of both these frameworks is that separate experiments targeting just one sub-phase at a time are run back-to-back. ...
Synergism between different phases gives rise to chemical, biological or environmental reactivity, thus it is increasingly important to study samples intact. Here, SASSY (SimultAneous Solid and Solution spectroscopY) is introduced to simultaneously observe (and differentiate) all phases in multiphase samples using standard, solid‐state NMR equipment. When monitoring processes, the traditional approach of studying solids and liquids sequentially, can lead to information in the non‐observed phase being missed. SASSY solves this by observing the full range of materials, from crystalline solids, through gels, to pure liquids, at full sensitivity in every scan. Results are identical to running separate ¹³C CP‐MAS solid‐state and ¹³C solution‐state experiments back‐to‐back but requires only a fraction of the spectrometer time. After its introduction, SASSY is applied to process monitoring and finally to detect all phases in a living freshwater shrimp. SASSY is simple to implement and thus should find application across all areas of research.
The development of stimuli-responsive nanomaterials holds immense promise for enhancing the efficiency and effectiveness of water treatment processes. These smart materials exhibit a remarkable ability to respond to specific external stimuli, such as light, pH, or magnetic fields, and trigger the controlled release of encapsulated pollutants. By precisely regulating the release kinetics, these nanomaterials can effectively target and eliminate contaminants without compromising the integrity of the water system. This review article provides a comprehensive overview of the advancements in light-activated and pH-sensitive nanomaterials for controlled pollutant release in water treatment. It delves into the fundamental principles underlying these materials' stimuli-responsive behaviour, exploring the design strategies and applications in various water treatment scenarios. In particular, the article indicates how integrating stimuli-responsive nanomaterials into existing water treatment technologies can significantly enhance their performance, leading to more sustainable and cost-effective solutions. The synergy between these advanced materials and traditional treatment methods could pave the way for innovative approaches to water purification, offering enhanced selectivity and efficiency. Furthermore, the review highlights the critical challenges and future directions in this rapidly evolving field, emphasizing the need for further research and development to fully realize the potential of these materials in addressing the pressing challenges of water purification.
