Search Results (233)

Mercury (Hg) contamination in water and soil poses severe ecological and human health risks, yet conventional sorbents often suffer from limited capacity, selectivity, and stability. Here, we report a bifunctional porous organic polymer (AMTD-TCT) rationally constructed by covalently crosslinking 2-amino-5-mercapto-1,3,4-thiadiazole with trichlorotriazine, thereby integrating abundant sulfur and nitrogen coordination sites within a stable mesoporous framework. AMTD-TCT exhibits an ultrahigh Hg(II) adsorption capacity of 1257.7 mg g⁻¹, far exceeding most reported porous sorbents. Adsorption follows monolayer chemisorption, governed by strong S–Hg and N–Hg coordination and Na⁺/Hg²⁺ ion exchange, while hierarchical porosity ensures rapid diffusion and efficient utilization of active sites. The polymer maintains robust performance over a wide pH range and demonstrates strong retention with minimal desorption, underscoring its environmental durability. These findings highlight AMTD-TCT as a highly effective and scalable platform for Hg(II) remediation in complex aqueous–soil systems and illustrate a generalizable molecular design strategy for developing multifunctional porous polymers in advanced separation and purification technologies. Full article

Thorium has emerged as a promising alternative to uranium in nuclear energy systems due to its higher natural abundance, favorable conversion to fissile ²³³U, and reduced generation of long-lived transuranic waste. This review provides a comprehensive overview of advanced techniques for thorium recovery from primary ores and secondary resources. The main mineralogical carriers—including monazite, thorianite, thorite, and cheralite as well as industrial by-products such as rare-earth processing tailings—are critically examined with respect to their occurrence and processing potential. Physical enrichment methods (gravity, magnetic, and electrostatic separation) and hydrometallurgical approaches (acidic and alkaline leaching) are analyzed in detail, highlighting their efficiencies, limitations, and environmental implications. Particular emphasis is placed on modern separation strategies such as solvent extraction with organophosphorus reagents, diglycolamides, and ionic liquids, as well as extraction chromatography, nanocomposite sorbents, ion-imprinted polymers, and electrosorption on carbon-based electrodes. These techniques demonstrate significant progress in enhancing selectivity, reducing reagent consumption, and enabling recovery from low-grade and secondary feedstocks. Environmental and radiological aspects, including waste minimization, immobilization, and regulatory frameworks, are discussed as integral components of sustainable thorium management. Finally, perspectives on hybrid technologies, digital process optimization, and economic feasibility are outlined, underscoring the need for interdisciplinary approaches that combine chemistry, materials science, and environmental engineering. Collectively, the analysis highlights the transition from conventional practices to integrated, scalable, and environmentally responsible technologies for thorium recovery. Full article

Wastewater analysis plays a central role in monitoring patterns of drug use within specific populations. It provides objective and real-time estimates of consumption, with minimal ethical concerns. In the current European context, drugs of abuse continue to be detected in wastewater, with varying incidences across countries. Their monitoring enables the prioritisation of public health and legal interventions by healthcare professionals and drug monitoring agencies. Therefore, the development and implementation of efficient methodologies for monitoring drugs of abuse in wastewater samples is of critical importance. This systematic review aims to explore the use of miniaturised sample extraction techniques based on solid-phase microextraction for the determination of drugs of abuse in wastewater. In fact, the extraction procedure must be fast, effective, and selective in order to retain the analytes of interest. Miniaturised techniques have thus emerged as promising alternatives to conventional methods. Magnetic solid-phase extraction (MSPE) and molecularly imprinted polymers (MIPs) represent the most widely applied solid-phase microextraction techniques in recent years for the analysis of drugs of abuse in wastewater. Looking ahead, future perspectives include the development of eco-friendly workflows, automated and time-efficient techniques, increasingly selective sorbents, and robust analytical methods. Full article

Polypyrrole, which belongs to the conducting polymer family, has demonstrated profound potential in advanced water purification applications due to its inherent electrical conductivity, environmental stability, and tunable surface chemistry. As a sorbent, PPy exhibits high sorption capacity for aquatic contaminants, including heavy metals, pharmaceutical compounds, and their metabolites, as well as synthetic dyes. The removal efficiency is correlated to a complex interaction mechanism involving electrostatic attractions, redox activity, and π–π stacking. Recent advances have expanded the utility by further developing nanostructured PPy-based (nano)composites, which elevate sorption performance by increasing surface area, mechanical integrity, and selective affinity. In addition, its integration into membrane technologies has enabled the design of an effective filtration system with improved selectivity and regeneration capabilities. Moreover, PPy is effective in electrochemical processes of water treatment, including capacitive deionization and electrochemically assisted sorption, opening novel paths towards energy-efficient pollutant removal. The multifunctionality of PPy as a sorbent material highlights its value as an important material for water treatment, with the capability of extended modification tailored for emerging environmental needs revised in this work. Full article

Tetrabromobisphenol A (TBBPA) is a flame retardant widely added to polymer products. Successful isolation of target analytes from complex natural matrices relies on extraction materials that can selectively interact with the analytes. In this context, the use of magnetic nanostructured adsorbents, such as magnetic molecularly imprinted polymer systems (MMIPs), can play a key role in both selective matrix–analyte interactions and separation processes. Here, to achieve different TBBPA loadings, Fe₃O₄ nanoparticles (NPs) were coated with chitosan (CS) or (3-aminopropyl) triethoxysilane (APTES). Moreover, to further promote template–NP interactions and modulate the polymeric shell thickness of MMIPs, 3,4-dihydroxyhydrocinnamic acid (HC) was covalently bonded in different amounts to APTES-functionalized MNPs. Thermal, SEM, and elemental analyses showed a different coating degree of the nanocomposites (Fe₃O₄@CS-MIP size d = 77 nm and Fe₃O₄@APTES-MIP d = 20 nm). In addition, it was confirmed that the adsorption mechanism of TBBPA on Fe₃O₄@APTES-HCX-MIPs was due to specific interactions between the systems and the analyte, unlike non-imprinted analogs (MNIPs). Among the developed systems, the Fe3O4@APTES-HC0.7-MIP sample showed the best extraction efficiency (85%) associated with good discharge efficiency (70%). Furthermore, this nanocomposite displayed high selectivity towards TBBPA (ε > 1) and good extraction efficiency in three consecutive cycles (67%), demonstrating great potential in the environmental field. Full article

Direct Air Capture (DAC) is emerging as a critical climate change mitigation strategy, offering a pathway to actively remove atmospheric CO₂. This comprehensive review synthesizes advancements in DAC technologies, with a particular emphasis on the pivotal role of nanostructured solid sorbent materials. The work critically evaluates the characteristics, performance, and limitations of key nanomaterial classes, including metal–organic frameworks (MOFs), covalent organic frameworks (COFs), zeolites, amine-functionalized polymers, porous carbons, and layered double hydroxides (LDHs), alongside solid-supported ionic liquids, highlighting their varied CO₂ uptake capacities, regeneration energy requirements, and crucial water sensitivities. Beyond traditional temperature/pressure swing adsorption, the review delves into innovative DAC methodologies such as Moisture Swing Adsorption (MSA), Electro Swing Adsorption (ESA), Passive DAC, and CO₂-Binding Organic Liquids (CO₂ BOLs), detailing their unique mechanisms and potential for reduced energy footprints. Despite significant progress, the widespread deployment of DAC faces formidable challenges, notably high capital and operational costs (currently USD 300–USD 1000/tCO₂), substantial energy demands (1500–2400 kWh/tCO₂), water interference, scalability hurdles, and sorbent degradation. Furthermore, this review comprehensively examines the burgeoning global DAC market, its diverse applications, and the critical socio-economic barriers to adoption, particularly in developing countries. A comparative analysis of DAC within the broader carbon removal landscape (e.g., CCS, BECCS, afforestation) is also provided, alongside an address to the essential, often overlooked, environmental considerations for the sustainable production, regeneration, and disposal of spent nanomaterials, including insights from Life Cycle Assessments. The nuanced techno-economic landscape has been thoroughly summarized, highlighting that commercial viability is a multi-faceted challenge involving material performance, synthesis cost, regeneration energy, scalability, and long-term stability. It has been reiterated that no single ‘best’ material exists, but rather a portfolio of technologies will be necessary, with the ultimate success dependent on system-level integration and the availability of low-carbon energy. The review paper contributes to a holistic understanding of cutting-edge DAC technologies, bridging material science innovations with real-world implementation challenges and opportunities, thereby identifying critical knowledge gaps and pathways toward a net-zero carbon future. Full article

One of the most interesting and poorly studied carriers of medicinal substances is the polymer clay composite material (PCCM). Bentonite clays are used in pharmacy for the manufacturing of various dosage forms, as well as in the adsorption of drugs to slow their release. Polymer–clay nanocomposites have demonstrated significantly improved properties compared to pure polymers. A review of recent scientific advances has shown promising results regarding the application of polymer–clay materials in medicine and bioengineering, particularly in the development of carrier sorbents with prolonged action for controlled drug release. As a result, interest in polymer–clay systems is steadily growing and gaining momentum. This paper focuses on the structure and properties of bentonite clays, including their sorption, ion exchange, binding, and rheological properties. The methods for preparing intercalated and exfoliated nanocomposites, such as radical intercalative polymerization in situ on clay surfaces, are reviewed. Furthermore, the improved efficacy and exposure times of PCCMs, combined with their enhanced bactericidal properties, are analyzed for the creation of universal and multifunctional preparations for medical use. Full article

Porphyrins and their derivatives are excellent materials with specific physical and photochemical properties in medical, chemical, and technological applications. In chemistry, their properties are applied to create new functional materials with specific characteristics, such as porphyrin-based sorbents combined with porous organic polymers, silica, carbon nanostructures, or metal–organic frameworks. This review covers the applications of porphyrins and metalloporphyrins in preparing and using sorbents for metal ion enrichment and their separation. Uncommon applications that utilize specific properties of porphyrins, such as light-enhanced processes and redox properties for selective sorption and photocatalytic conversion of metal ions, are also discussed. These applications suggest new fields of use, such as the removal or recycling of metals from electronic waste or the selective elimination of heavy metals from the environment. Full article

In this study, polymer films based on the inorganic sorbents Al₂O₃, ZrO₂ and SiO₂-phenyl with repellent N,N-diethyl-3-methylbenzamide were prepared and used as functional textile coatings. The high sorption activity of oxides with respect to N,N-diethyl-3-methylbenzamide (63–239 mg/g) allows for the use of these compounds as repellent carrier materials, and their mixture with polyacrylates allows for the formation of functional coatings–polymer films. Scanning electron microscopy and Fourier transform infrared spectroscopy results revealed that the inorganic sorbents Al₂O₃, ZrO₂ and SiO₂-phenyl were successfully anchored in the polyacrylate structure, and the FTIR spectra confirmed the presence of repellent molecules. The thermal diffusion parameters of N,N-diethyl-3-methylbenzamide were also calculated via thermogravimetric analysis and high-performance liquid chromatography with diode array detection. The highest thermal diffusion rates and concentrations were observed for the material with Al₂O₃ (up to 148.3∙10⁻⁹ mol at 200 °C), and lower values for ZrO₂ and SiO₂-phenyl (up to 15.2∙10⁻⁹ mol and 34.3∙10⁻⁹ mol at 200 °C, respectively). The heat flux parameter J_f was also calculated according to Onsager’s theory and Fourier’s law. The release of repellent from polymeric materials can be achieved by applying less heat than that required to reach the boiling point of N,N-diethyl-3-methylbenzamide. Full article

Microporous soluble polymers attract great attention as materials for membrane gas separation, gas storage and transportation, as sorbents, supports for catalysts, and matrices for mixed matrix membranes. The key problems in the development of this area of polymer chemistry include the search for methods of controlling the porous structure parameters and ensuring the stability of their properties over time. In this connection, a fruitful approach is to introduce bulky and rigid, often framework carbocyclic moieties into the polymer backbones and side chains. This review discusses the effect of carbocyclic moieties on gas transport properties, BET surface area, and FFV of glassy polymers, such as polyacetylenes, polynorbornenes, polyimides, and ladder and partially ladder polymers. In the majority of cases, the incorporation of carbocyclic moieties makes it possible to controllably increase these three parameters. Carbocyclic moieties can also improve CO₂/gas separation selectivity, which is displayed for ladder polymers and polynorbornenes. Full article

(1→3)-α-d-Glucan is an important component of the cell wall of most fungi. The polymer has many applications, including as a therapeutic agent in the prevention or treatment of various diseases, as well as a heavy metal sorbent and a component of new materials used in the plastics industry. The presence of (1→3)-α-d-glucan (water-insoluble, alkali-soluble polysaccharide) in the cell wall of Pleurotus djamor (pink oyster mushroom) was confirmed using specific fluorophore-labeled antibodies. Therefore, the water-insoluble fraction (WI-ASF) of P. djamor B123 fruiting bodies was isolated by alkaline extraction and used for further analyses. The structural features of the WI-ASF were determined by composition analysis, linkage analysis, Fourier transform infrared and Raman spectroscopy, ¹H and ¹³C nuclear magnetic resonance spectroscopy, scanning electron microscopy, as well as viscosity, specific rotation, and gel permeation chromatography. These studies revealed the presence of glucose units linked by α-glycosidic bonds and scanty amounts of mannose and xylose. Furthermore, methylation analysis of WI-ASF demonstrated that the (1→3)-linked glucopyranose (Glcp) is the primary moiety (86.4%) of the polymer, while the 3,4- and 3,6-substituted hexoses are the branching residues of the glucan. The results of chemical and spectroscopic investigations indicated that the analyzed WI-ASF is a (1→3)-linked α-d-glucan type with a molecular weight of 552 kDa. Full article

A sol-gel approach was used to prepare a thin hydrogel membrane based on an organic-inorganic polymer matrix embedded with pre-synthesized gold nanoparticles (AuNPs). The organic polymers utilized were poly(vinyl alcohol) (PVA) and poly(ethylene oxide) 400 (PEO) while tetraethoxysilane (TEOS) served as a precursor for the inorganic silica polymer. AuNPs were synthesized using D-glucose as a reducing agent and starch as a capping agent. A mixture of PVA, PEO, pre-hydrolyzed TEOS, and AuNP dispersions was cast and dried at 50 °C to obtain the hybrid hydrogel membrane. The structure, morphology, and optical properties of the nanocomposite membrane were analyzed using TEM, SEM, XRD, and UV-Vis spectroscopy. The newly designed hybrid hydrogel membrane was utilized as an efficient sorbent for the simultaneous speciation analysis of valence species of chromium and manganese in water samples via solid-phase extraction. This study revealed that Cr(III) and Mn(II) could be simultaneously adsorbed onto the PVA/PEO/SiO₂/AuNP membrane at pH 9 while Cr(VI) and Mn(VII) remained in solution due to their inability to bind under these conditions. Under optimized parameters, detection limits and relative standard deviations were determined for chromium and manganese species. The developed analytical method was successfully applied for the simultaneous speciation analysis of chromium and manganese in drinking water and wastewater samples. Full article

Graphene’s incorporation into polymers has enabled the development of advanced polymer/graphene nanocomposites with superior properties. This study focuses on the use of a microcellular foamed polystyrene (PS)/graphene (GP) nanocomposite (3 wt%) for nickel (II) ion removal from aqueous solutions. Adsorption behavior was evaluated through FTIR, TEM, SEM, TGA, and XRD analyses. Key factors, including initial ion concentration, pH, temperature, and sorbent dosage, were examined. Results showed optimal nickel removal at specific pH levels with removal efficiency decreasing from 91 to 80% as Ni (II) concentrations increased from 10 to 100 mg/L. The adsorption capacity improved from 11 to 130 mg/g. Equilibrium data aligned with Langmuir and Freundlich isotherm models, while adsorption kinetics followed a second-order kinetic model. These findings highlight the potential of PS/GP nanocomposites for nickel ion removal, offering a promising solution for small-scale industrial applications. Full article

Composite adsorbents based on a natural biopolymer matrix of chitosan, to which 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide and its Se derivative were attached, were synthesized. A complex of physicochemical analysis methods indicates that the direct introduction of a matrix with high ionic permeability into the reaction mixture contributes to the formation of homogeneous particles of composite with developed surface morphology, which enhances the kinetic and capacitive parameters of uranium sorption in liquid media. It has been established that the direct introduction of a matrix with high ionic permeability into the reaction mixture contributes to the formation of homogeneous particles with a developed surface morphology, which enhances the kinetic and capacitive parameters of uranium sorption in liquid media. The synthesized materials had increased sorption-selective properties towards uranium in the pH range from 4 to 9 under static sorption conditions. The formation of the Se derivative of amidoxime during its attachment to the polymer matrix (Se-chit) contributes to the creation of a more chemically stable and highly effective adsorbent, compared to the direct binding of 4-amino-N′-hydroxy-1,2,5-oxadiazole-3-carboximidamide with chitosan (43AF-chit). The optimal parameters for the synthesis of materials were established. It was demonstrated that the ratio of amidoxime to chitosan should be within the range of 2:1 to 1:2. As the mass content of chitosan increases, the material gradually dissolves and transforms into a gel, resulting in the formation of liquid radioactive waste with a complex chemical composition. It was found that the kinetic sorption parameters of composite materials increase 2–10 times compared to those of non-composite materials. The sorption capacity of uranium in solutions with pH 6 and pH 8 can reach approximately 400–450 mg g⁻¹. Under dynamic sorption conditions, the effective filtration cycle values (before uranium slips into the filtrate ≥ 50%) improve significantly when transitioning from a non-composite adsorbent to a composite one: increasing from 50 to 800 b.v. for pH 6 and from 2700 to 4000 b.v. for pH 8. These results indicate that the synthesized sorbents are promising materials for uranium removal from liquid media, suitable for both purification and the recovery of radionuclides as valuable raw materials. Full article

A new composite material with enhanced sorption-selective properties for uranium recovery from liquid media has been obtained. Sorbents were synthesized through a polycondensation reaction of a mixture of 4-amino-N’-hydroxy-1,2,5-oxadiazole-3-carboximidamide (hereinafter referred to as amidoxime) and SiO₂ in an environment of organic solvents (acetic acid, dioxane) and highly porous SiO₂. To establish optimal conditions for forming the polymer sorption-active part and the synthesis as a whole, a series of composite adsorbents were synthesized with varying amidoxime/matrix ratios (35/65, 50/50, 65/35). The samples were characterized with FT-IR, XRD, SEM, EDX, XRFES spectroscopy and TGA. Under static conditions of uranium sorption, the dependence of the efficiency of radionuclide recovery from mineralized solutions of various acidities on the ratio of the initial components was established. In the pH range from 4 to 8 (inclusive), the uranium removal efficiency exceeds 95%, while the values of the distribution coefficients (Kd) exceed 10⁴ cm³g⁻¹. It was demonstrated that an increase in the surface development of the sorbents enhances such kinetic parameters of uranium sorption as diffusion rate by 10–20 times compared to non-porous materials. The values of the maximum static capacity exceed 700 mg g⁻¹. The enhanced availability of adsorption centers, achieved through the use of a porous SiO₂ matrix, significantly improves the kinetic parameters of the adsorbents. A composite with optimal physicochemical and sorption properties (amidoxime/matrix ratio of 50/50) was examined under dynamic conditions of uranium sorption. It was found that the maximum dynamic sorption capacity of porous materials is four times greater compared to that of a non-porous adsorbent Se-init. The effective filter cycle exceeds 3200 column volumes—twice that of an adsorbent with a monolithic surface. These results indicate the promising potential of the developed materials for uranium sorption from liquid mineralized media under dynamic conditions across a wide pH range. Full article