Mechanistic evaluation of metformin drug confiscation from liquid phase on itaconic acid/kaolin hydrogel nanocomposite

Highly effective removal of basic fuchsin dye using carboxymethyl konjac glucomannan grafted acrylic acid-acrylamide/montmorillonite composite hydrogel

This study developed a nanocomposite hydrogel, CAM4-MMT, for efficiently removing basic fuchsin dye from water. The hydrogel was prepared by grafting a copolymer of acrylic acid (AA) and acrylamide (AM) onto carboxymethyl konjac glucomannan (CMKGM), and doped with montmorillonite (MMT), exhibited excellent thermal stability, a porous inner structure, large specific surface area (1.407 m2/g), and high swelling capacity (107.3 g/g). The hydrogel achieved a maximum adsorption capacity of 694.1 mg/g and a removal rate of 99.5 %. The Langmuir isotherm and pseudo-second-order kinetic model best described the adsorption process. Regeneration and reuse tests confirmed that the hydrogel has excellent recyclability. In conclusion, the CAM4-MMT composite hydrogel efficiently removed basic fuchsin from water solutions, offering a new scheme for eliminating basic fuchsin using natural polysaccharides with promising applications.

Monte Carlo, molecular dynamic, and experimental studies of the removal of malachite green using g-C3N4/ZnO/Chitosan nanocomposite in the presence of a deep eutectic solvent

Deep-eutectic solvents (DES) have emerged as promising candidates for preparing nanocomposites. In this study, a DES-based graphitic carbon nitride (g-C3N4)/ZnO/Chitosan (Ch) nanocomposite was synthesized to remove malachite green (MG) dye from water. The DES was prepared by mixing and heating citric acid as a hydrogen bond acceptor and lactic acid as a hydrogen bond donor. This is the first report of the removal of MG using DES-based nanocomposites. Experiments on kinetics and isothermal adsorption were conducted to systematically explore the adsorption performances of nanocomposite toward dye. At 25 °C, the highest adsorption performance was obtained with alkaline media (>90 % removal). The greatest adsorption capacity (qm) was 59.52 mg g-1 at conditions (30 mg L-1 MG solution, pH 9, 3 mg nanocomposite per 10 mL of MG solution, 25 °C, 150 rpm, and 150 min) based on the calculation from the best-fitting isotherm model (Langmuir). The adsorption process was most appropriately kinetically described by the PSO model. The Monte Carlo (MC) and molecular dynamic (MC) results are correlated with experimental findings to validate the theoretical predictions and enhance the overall understanding of the adsorption process. Electronic structure calculations reveal the nature of interactions, including hydrogen bonding and electrostatic forces, between the nanocomposite and MG molecules.

In-silico mechanistic analysis of adsorption of Iodinated Contrast Media agents on graphene surface

The study aims at assessing the potential of graphene-based adsorbents to reduce environmental impacts of Iodinated Contrast Media Agents (ICMs). We analyze an extensive collection of ICMs. A modeling approach resting on molecular docking and Density Functional Theory simulations is employed to examine the adsorption process at the molecular level. The study also relies on a Quantitative Structure-Activity Relationship (QSAR) modeling framework to correlate molecular properties with the adsorption energy (Ead) of ICMs, thus enabling identification of the key mechanisms underpinning adsorption and of the key factors contributing to it. A collection of distinct QSAR-based models is developed upon relying on Multiple Linear Regression and a standard genetic algorithm method. Having at our disposal multiple models enables us to take into account the uncertainty associated with model formulation. Maximum Likelihood and formal model identification/discrimination criteria (such as Bayesian and/or information theoretic criteria) are then employed to complement the traditional QSAR modeling phase. This has the advantage of (a) providing a rigorous ranking of the alternative models included in the selected set and (b) quantifying the relative degree of likelihood of each of these models through a weight or posterior probability. The resulting workflow of analysis enables one to seamlessly embed DFT and QSAR studies within a theoretical framework of analysis that explicitly takes into account model and parameter uncertainty. Our results suggest that graphene-based surfaces constitute a promising adsorbent for ICMs removal, π-π stacking being the primary mechanism behind ICM adsorption. Furthermore, our findings offer valuable insights into the potential of graphene-based adsorbent materials for effectively removing ICMs from water systems. They contribute to ascertain the significance of various factors (such as, e.g., the distribution of atomic van der Waals volumes, overall molecular complexity, the presence and arrangement of Iodine atoms, and the presence of polar functional groups) on the adsorption process.

Recent advances in the application of clay-containing hydrogels for hemostasis and wound healing

INTRODUCTION

Immediate control of bleeding and anti-infection play important roles in wound management. Multiple organ dysfunction syndrome and death may occur if persistent bleeding, hemodynamic instability, and hypoxemia are not addressed. The combination of clay and hydrogel provides a new outlet for wound hemostasis. In this review, the current research progress of hydrogel/clay composite hemostatic agents was reviewed.

AREAS COVERED

This paper summarizes the characteristics of several kinds of clay including kaolinite, montmorillonite, laponite, sepiolite, and palygorskite. The advantages and disadvantages of its application in hemostasis were also summarized. Future directions for the application of hydrogel/clay composite hemostatic agents are presented.

EXPERT OPINION

Clay can activate the endogenous hemostatic pathway by increasing blood cell concentration and promoting plasma absorption to accelerate the hemostasis. Clay is antimicrobial due to the slow release of metal ions and has a rich surface charge with a high affinity for proteins and cells to promote tissue repair. Hydrogels have some properties such as good biocompatibility, strong adhesion, high stretchability, and good self-healing. Despite promising advances, hydrogel/clay composite hemostasis remains a limitation. Therefore, more evidence is needed to further elucidate the risk factors and therapeutic effects of hydrogel/clay in hemostasis and wound healing.

Efficient and Selective Removal of Heavy Metals and Dyes from Aqueous Solutions Using Guipi Residue-Based Hydrogel

The presence of organic dyes and heavy metal ions in water sources poses a significant threat to human health and the ecosystem. In this study, hydrogel adsorbents for water pollution remediation were synthesized using Guipi residue (GP), a cellulose material from Chinese herbal medicine, and chitosan (CTS) through radical polymerization with acrylamide (AM) and acrylic acid (AA). The characteristics of the hydrogels were analyzed from a physicochemical perspective, and their ability to adsorb was tested using model pollutants such as Pb2+, Cd2+, Rhodamine B (RhB), and methyl orange (MO). The outcomes revealed that GP/CTS/AA-co-AM, which has improved mechanical attributes, effectively eliminated these pollutants. At a pH of 4.0, a contact duration of 120 min, and an initial concentration of 600 mg/L for Pb2+ and 500 mg/L for Cd2+, the highest adsorption capabilities were 314.6 mg/g for Pb2+ and 289.1 mg/g for Cd2+. Regarding the dyes, the GP/CTS/AA-co-AM hydrogel displayed adsorption capacities of 106.4 mg/g for RhB and 94.8 mg/g for MO, maintaining a stable adsorption capacity at different pHs. Compared with other competitive pollutants, GP/CTS/AA-co-AM demonstrated a higher absorption capability, mainly targeted toward Pb2+. The adsorption processes for the pollutants conformed to pseudo-second-order kinetics models and adhered to the Langmuir models. Even after undergoing five consecutive adsorption and desorption cycles, the adsorption capacities for heavy metals and dyes remained above 70% and 80%. In summary, this study effectively suggested the potential of the innovative GP/CTS/AA-co-AM hydrogel as a practical and feasible approach for eliminating heavy metals and dyes from water solutions.

Appraisal of the adsorption potential of novel modified gellan gum nanocomposite for the confiscation of methylene blue and malachite green

In the present investigation a novel, environmentally affable and economical, modified gellan gum nanocomposite (MAA-g-GG/Ppy/MMT) was fabricated via free-radical polymerization for the liquid-phase mitigation of Methylene blue (MB) and Malachite green (MG) dyes. The innovation of this work is substantiated by the intentional combination of diverse materials, the strategic incorporation of polypyrrole for enhanced adsorption, and the thoughtful addition of MMT as a nanofiller to address mechanical strength and improve adsorption capacity. The physico-chemical facets of MAA-g-GG/Ppy/MMT and its interaction with the dye molecules were elucidated using FT-IR, SEM-EDX, BET, TEM, and XRD techniques. The optimum conditions for the sorption of MB and MG were deemed to be dosage (1.2 g/L for both dyes), contact time (50 min for both dyes), initial MG/MB concentration (MB = 40 mg/L & MG = 30 mg/L), and pH (MB = 10 & MG = 7). The Freundlich isotherm was identified as the most suitable model, as evidenced by the highest R2 value (∼0.999), indicating multilayer adsorption. The pseudo second-order model appraised the kinetic data. Thermodynamic findings revealed the adsorption process to be spontaneous, viable and exothermic which was ascertained by negative ∆H⸰ values (-22.8 kJ/mol for MB and -18.3 kJ/mol for MG). The substantial Langmuir adsorption capacity (Qm: MG =185.185; MB = 344.827) can be ascribed to the reason for strong interactions between MAA-g-GG/Ppy/MMT and dyes. The high reliability of MAA-g-GG/Ppy/MMT was determined by the regeneration studies that worked up to four cycles for both dyes. The real water (distilled water, tap water, and river water) samples spiked with MG/MB demonstrated a substantial uptake of dyes (>85 %) and the marginal influence of ionic strength on the adsorptive potential of MAA-g-GG/Ppy/MMT validated its efficacy for the decontamination of real effluents. The forces of attraction between the dyes and MAA-g-GG/Ppy/MMT included van der Waals, electrostatic forces of attraction, and π-π interaction. This green, economical, and viable MAA-g-GG/Ppy/MMT will prove to be an efficient adsorbent for the decontamination process of sequestration of dyes to achieve a sustainable environment.

Polymeric hydrogels-based materials for wastewater treatment

Low-cost and reliable wastewater treatment is a relevant issue worldwide to reduce the concentration of environmental pollutants. Industrial effluents containing dyes, heavy metals, and other inorganic and organic compounds can pollute water resources; therefore, novel technologies are required to mitigate and control their release into the environment. Adsorption is one of the simplest methods for treating contaminated water in which a wide spectrum of adsorbents can be used to remove emerging compounds. Hydrogels are interesting materials with high adsorption capacities that can be synthesized via green routes. These adsorbents are promising for large-scale industrial wastewater treatment applications; however, gaps still exist in achieving sustainable commercial implementation. This review focuses on the discussion and analysis of preparation, characterization, and adsorption properties of hydrogels for water purification. The advantages of these polymeric materials for water treatment were analyzed, including their performance in the removal of different organic and inorganic contaminants. Recent advances in the functionalization of hydrogels and the synthesis of novel composites have also been described. The adsorption capacities of hydrogel-based adsorbents are higher than 500 mg/g for different organic and inorganic pollutants, and can reach values of up to >2000 mg/g for organic compounds, significantly outperforming other materials reported for water cleaning. The main interactions involved in the adsorption of water pollutants using hydrogel-based adsorbents were described and explained to allow the interpretation of their removal mechanisms. The current challenges in the implementation of hydrogels for water purification in real-life operations are also highlighted. This review provides an updated picture of hydrogels as interesting materials to address water depollution worldwide.

Removal of Pharmaceuticals and Personal Care Products (PPCPs) by Free Radicals in Advanced Oxidation Processes

As emerging pollutants, pharmaceutical and personal care products (PPCPs) have received extensive attention due to their high detection frequency (with concentrations ranging from ng/L to μg/L) and potential risk to aqueous environments and human health. Advanced oxidation processes (AOPs) are effective techniques for the removal of PPCPs from water environments. In AOPs, different types of free radicals (HO·, SO₄·^-, O₂·^-, etc.) are generated to decompose PPCPs into non-toxic and small-molecule compounds, finally leading to the decomposition of PPCPs. This review systematically summarizes the features of various AOPs and the removal of PPCPs by different free radicals. The operation conditions and comprehensive performance of different types of free radicals are summarized, and the reaction mechanisms are further revealed. This review will provide a quick understanding of AOPs for later researchers.

Synthesis of a biobased resin and its screening as an alternative adsorbent for organic and inorganic micropollutant removal

The sol-gel route was used to synthesize a biophenolic resin from a blend of Kraft black liquor and condensed tannin. The biobased resin has an amorphous structure and diversified surface functional groups. The biomaterial thermal stability was improved by Kraft black liquor, which increased the fixed carbon yield by 19.78% in an oxidant medium and 9.07% in an inert medium. Moreover, the presence of fixed carbon and char is positively related to the material flame retardant property. Additionally, impedance measurements were used to understand the physical phenomena occurring at the polymeric matrix's interface and the material's final properties. The biobased resin characterization and the considerable increase in the presence of micropollutants in surface and water bodies suggest the new biomaterial application in the adsorption process. Thus, its adsorption capacity toward several organic and inorganic micropollutants and its effectiveness in complex water matrices were evaluated. Methylene blue was used as a model compound to assess the influence of the resin composition on the adsorption capacity, and the type H isotherm indicates the high affinity of the biobased resin toward the micropollutant. The adsorption occurs in multilayer by intermolecular interaction and electrostatic forces. The amount of Kraft black liquor favored the adsorption, and the adsorption capacity was greater than 1250 mg g-1. When inorganic compounds were evaluated, the carboxyl and phenol groups favor the biomaterial affinity toward metal ions. Cu2+ and Ni2+ were completely removed from the contaminated water, and the adsorption capacity of the other inorganic compounds was: Pb2+ (36.97 mg g-1), Al3+ (22.17 mg g-1), Ba2+ (12.76 mg g-1), Ag1+ (33.85 mg g-1), and Fe2+ (19.44 mg g-1). In contrast, the adsorption capacity of the organic micropollutants was: 2,4-D (3.09 mg g-1), diuron (5.89 mg g-1), atrazine (2.71 mg g-1), diclofenac (2.04 mg g-1), caffeine (5.79 mg g-1), acetaminophen (4.80 mg g-1), methylene Blue (106.66 mg g-1), and methyl orange (30.48 mg g-1). The results pointed that the adsorption efficiency of organic micropollutants increases with the distribution coefficient (logD), indicating the biobased resin affinity toward more lipophilic compounds and ionized species.

Sustainable Mitigation of Paracetamol with a Novel Dual-Functionalized Pullulan/Kaolin Hydrogel Nanocomposite from Simulated Wastewater

In the present investigation, a novel, green, and economical dual-functionalized pullulan/kaolin hydrogel nanocomposite (f-PKHN) was fabricated and subsequently applied for the liquid-phase decontamination of paracetamol (PCT), a pharmaceutical pollutant. Pullulan and kaolin were functionalized with l-asparagine and gallic acid, respectively. The physicochemical facets of the functionalized pullulan/kaolin hydrogel nanocomposite and its interactive behavior with PCT were elucidated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), and elemental mapping. The process parameters along with the isotherm, kinetics, and thermodynamics were methodically appraised via a batch technique to unveil the adsorption performance of the as-fabricated hydrogel nanocomposite. The adsorption isotherm and kinetics of PCT uptake by f-PKHN conform well to Freundlich and pseudo-second-order models, respectively. Relying on hydrogen bonding, n-π, and van der Waals interactions, the maximum adsorption capacity was 332.54 mg g^-1, higher than for most of the previous adsorbents reported in the literature for PCT removal. Thermodynamic calculations corroborated endothermic, spontaneous, and feasible adsorption phenomena. The maintenance of a high uptake percentage (69.11%) in the fifth consecutive adsorption-desorption cycle implied the significant reusable potential of f-PKHN. Swelling studies exhibited 90% swelling within 200 min, indicating the successful fabrication of a cross-linked hydrogel network. The real water (distilled water, tap water, and river water) samples spiked with PCT specified a significant uptake of PCT (>85%), and the minor influence of ionic strength on the adsorptive potential of f-PKHN validated its potentiality for the decontamination of real effluents. In conclusion, f-PKHN with substantial adsorption capacity, green characteristics, and excellent reusability can be reckoned with as a promising adsorbent for the de-escalation of PCT from aquatic sources as well as at the industrial level.

Evaluation of gum ghatti-g-poly(itaconic acid) magnetite nanocomposite as an adsorbent material for water purification

A porous hydrogel nanocomposite has been made by grafting poly(itaconic acid) on the polysaccharide, gum ghatti and by embedding magnetite nanoparticles in the copolymer gel matrix. This novel functional material Ggh-g-PIA/Fe₃O₄ was characterized by FTIR, TGA, SEM, EDS, XRD, BET, Zeta potential measurements and VSM techniques. The nanocomposite possesses mesoporous structure with high surface area and exhibits super-paramagnetic behavior due to the presence of magnetite nanoparticles. The hydrogel nanocomposite was evaluated as an adsorbent material for removal of dyes and divalent metal ions. Significant adsorption capacities of 410.2, 387.6, 416.5 and 401.4 mg g^-1 towards methylene blue, rhodamine 6G, Cu (II) and Hg (II) ions respectively were observed. The adsorption isotherms were well described by the Freundlich isotherm model and kinetic studies demonstrated the adsorption to be a pseudo second order kinetic process. Intraparticle diffusion model suggested adsorption to occur by a multi-step diffusion process. Thermodynamic studies indicated a spontaneous and endothermic adsorption. Further, the desorption study indicated the possibility of successful regeneration of the adsorbent. A high removal efficiency, recyclability, convenient recovery after use due to the magnetic nature makes this polysaccharide based nanocomposite an environment friendly adsorbent material for water purification.

Recent Advances in Biotechnological Itaconic Acid Production, and Application for a Sustainable Approach

Intense research has been conducted to produce environmentally friendly biopolymers obtained from renewable feedstock to substitute fossil-based materials. This is an essential aspect for implementing the circular bioeconomy strategy, expressly declared by the European Commission in 2018 in terms of "repair, reuse, and recycling". Competent carbon-neutral alternatives are renewable biomass waste for chemical element production, with proficient recyclability properties. Itaconic acid (IA) is a valuable platform chemical integrated into the first 12 building block compounds the achievement of which is feasible from renewable biomass or bio-wastes (agricultural, food by-products, or municipal organic waste) in conformity with the US Department of Energy. IA is primarily obtained through fermentation with Aspergillus terreus, but nowadays several microorganisms are genetically engineered to produce this organic acid in high quantities and on different substrates. Given its trifunctional structure, IA allows the synthesis of various novel biopolymers, such as drug carriers, intelligent food packaging, antimicrobial biopolymers, hydrogels in water treatment and analysis, and superabsorbent polymers binding agents. In addition, IA shows antimicrobial, anti-inflammatory, and antitumor activity. Moreover, this biopolymer retains qualities like environmental effectiveness, biocompatibility, and sustainability. This manuscript aims to address the production of IA from renewable sources to create a sustainable circular economy in the future. Moreover, being an essential monomer in polymer synthesis it possesses a continuous provocation in the biopolymer chemistry domain and technologies, as defined in the present review.