Search Results (53)

Due to the nearly identical chemical properties of Lu and Yb, the production of no-carrier-added (NCA) ¹⁷⁷Lu faces significant challenges in their separation. Achieving efficient and streamlined separation of Lu and Yb is crucial for the production of NCA ¹⁷⁷Lu. This study systematically investigated the separation performance of the commercial Rext-P350 extraction resin for Lu and Yb. Static adsorption experiments revealed that, at a solid–liquid ratio of 8 g/L, both Lu³⁺ and Yb³⁺ were nearly completely adsorbed, with saturation adsorption capacities of 25.8 mg/g and 21.5 mg/g, respectively. An increase in the nitric acid concentration in the aqueous phase significantly inhibited adsorption, but the separation factor for Lu³⁺/Yb³⁺ remained above 1.88. The adsorption kinetics followed a pseudo-second-order model (R² > 0.99), with equilibrium reached within 15 min, demonstrating fast adsorption kinetics. Characterization by SEM, FT-IR, and XPS confirmed the chemical coordination between the resin and Lu³⁺/Yb³⁺. Dynamic chromatographic separation experiments showed that the Rext-P350 resin exhibited significantly better separation performance for Lu³⁺/Yb³⁺ compared to 2-ethylhexylphosphoric acid mono-2-ethylhexyl ester (P507) extraction resin. Leveraging the excellent performance of Rext-P350 resin, a two-stage continuous extraction chromatography process was designed, achieving efficient separation of 0.045 mg of Lu³⁺ from 200 mg of Yb³⁺ with a Lu³⁺ purity of 90.9% and a yield of 98.4%. This study provides a feasible separation technique for the purification of NCA ¹⁷⁷Lu. Full article

This study aimed to develop an innovative resin composite with anti-biofouling properties, tailored to prosthesis fabrication in dentistry using a digital light processing (DLP) 3D-printing technique. The resin composite was formulated using a blend of dental monomers, with the integration of 2-methacryloyloxylethyl phosphorylcholine (MPC) with anti-biofouling behavior and γ-MPS-treated silica-zirconia powder for simultaneous mechanical reinforcement. The overall characterization of the resin composite was carried out using various contents of MPC incorporated into the resin (0–7 wt%) for examining the rheological behavior, photopolymerization, flexural strength/modulus, microstructure and anti-biofouling efficiency. The resin composite demonstrated a significant reduction in bacterial adhesion (97.4% for E. coli and 86.5% for S. aureus) and protein adsorption (reduced OD value from 1.3 ± 0.4 to 0.8 ± 0.2) with 7 wt% of MPC incorporation, without interfering with photopolymerization to demonstrate potential suitability for 3D printing without issues (p < 0.01, and p < 0.05, respectively). The incorporation and optimization of γ-MPS-treated silica-zirconia powder (10–40 vol%) enhanced mechanical properties, leading to a reasonable flexural strength (103.4 ± 6.1 MPa) and a flexural modulus (4.3 ± 0.4 GPa) at 30 vol% (n = 6). However, a further increase to 40 vol% resulted in a reduction in flexural strength and modulus; nevertheless, the results were above ISO 10477 standards for dental materials. Full article

Adsorbents derived from Merrifield’s resin and a reaction with three functionalizing ligands namely 1,2-ethanedithiol (M-EDT), 1,2-benzenedithiol (M-BDT), and 2-benzimidazolylmethylthio acetic acid (M-BITAA) were synthesized for the recovery and separation of PGMs from simulated solutions. M-EDT, M-BDT and M-BITAA resins were characterized by the FTIR, UV-Vis, TGA, CHNS and SEM techniques, which confirmed significant structural modifications in these resins. A batch adsorption study revealed that M-BITAA exhibited the highest capacity for Pd(II), with about 0.244 mmol·g⁻¹, while that of both M-EDT and M-BDT resins was below 0.094 mmol·g⁻¹. The adsorbents obeyed the Langmuir isotherm in 0.8 M HCl solution. Batch adsorption further showed, in a competitive study, that M-BITAA was not selective for Pd(II) but an attractive sorbent for other PGMs such as Pt(IV), which may be advantageous for solutions containing these PGMs. Full article

Polyphenol-rich extracts derived from agricultural by-products exhibit promising antiviral properties. This study evaluated the antiviral potential of extracts from red onion peels, vineyard prunings, olive prunings and chicory leaves against human coronavirus HuCoV-229E. Subcritical water extraction and resin adsorption techniques were applied to produce the extracts. The extracts were further characterised for their bioactive content, and three out of four extracts showed a high polyphenol content (>200 mg/g). The antiviral activity was assessed through viral infectivity and replication inhibition assays in human MRC-5 host cells. The results indicate that chicory leaf and red onion peel extracts demonstrated significant antiviral effects, with effective concentrations (EC₅₀) of 61.43 µg/mL and 10.1 µg/mL, respectively. Olive pruning extract exhibited moderate activity, while vineyard pruning extract showed limited efficacy. These findings suggest that polyphenol-rich agricultural by-products could serve as sustainable sources for antiviral agents, warranting further investigation into their mechanisms of action and potential applications against other coronaviruses, including SARS-CoV-2. Full article

Bisphenol A (BPA) is an industrial chemical used primarily in the manufacture of polycarbonate plastics and epoxy resins. BPA is considered an endocrine-disrupting chemical (EDC) because it interferes with hormonal systems. Over the decades, several techniques have been proposed for BPA removal in wastewaters. This study discusses recent advancements and progress of effective techniques for BPA removal, including membrane, adsorption, advanced oxidation process (AOPs), and biodegradation. The mechanisms of BPA adsorption on modified adsorbents include pore-filling, hydrophobic interactions, hydrogen bonding, and electrostatic interactions. Among the various agricultural waste adsorbents, Argan nut shell-microporous carbon (ANS@H20–120) exhibited the highest efficiency in removing BPA. Furthermore, the performance of magnetic treatment for activated carbon (AC) regeneration is introduced. According to the present study, researchers should prioritize agricultural waste-based adsorbents such as ACs, highly microporous carbons, nanoparticles, and polymers for the removal of BPA. In particular, the combination of adsorption and AOPs (advanced oxidations) is regarded as an efficient method for BPA removal. A series of relevant studies should be conducted at laboratory, pilot, and industrial scales for optimizing the application of agricultural waste-based AC to reduce BPA or other refractory pollutants from an aqueous environment. Full article

The triterpenoids from Inonotus hispidus exhibit several valuable bioactivities, including antioxidant, anti-inflammatory, and anticancer properties, making them highly sought-after for applications in functional foods. To obtain more I. hispidus triterpenoids with higher content for subsequent application in functional food, this study firstly screened a strain with a high triterpenoid yield for the cultivation of fruiting bodies. Afterwards, the static adsorption and desorption capacities of seven macroporous adsorption resins (MARs) for fruiting body triterpenoids were evaluated via static tests, and MAR HPD-600 showed the best performance. The static adsorption kinetics and isotherms of triterpenoids were analyzed further using MAR HPD-600, revealing that the adsorption process followed pseudo-second-order kinetics and the Freundlich model, indicating a spontaneous exothermic reaction. The dynamic adsorption–desorption parameters of MAR HPD-600 were subsequently evaluated to establish the optimal enrichment process. With the optimal strategy, the content of triterpenoids in the desorption solution of MAR HPD-600 increased from 26.72 to 129.28 mg/g, with a high yield of 75.48%. Conclusively, the application of MAR presents an efficient and cost-effective technique for extracting I. hispidus triterpenoids, making it well-suited for functional food production requirements. Full article

In this study, the chemically supported ionic liquids (CSILs) were synthesized by ultrasound irradiation (UI) to improve the preparation process and further strengthen the adsorption performance of CSILs towards vanadium (V). The impacts of UI and conventional mechanic stirring (CMS) on the synthesis and adsorption characteristics of polystyrene [1-butyl-3-methylimidazolium][nitrate] (PS[C₄mim][NO₃]) were comparatively investigated. The experimental results demonstrate that ultrasound can dramatically shorten the preparation time from 1920 min to 15 min, and HNO₃ dosage is reduced by 15.79%. Under the same adsorption conditions, the CSILs synthesized by UI achieve the maximal adsorption capacity towards vanadium (V) as 248.95 mg/g at 150 min, while the CSILs processed by CMS reach 223.90 mg/g at 105 min. Particularly, the adsorption capacity of CSILs synthesized by UI can be maintained as 96.42% of the initial value after 10 cycles of adsorption–desorption, while that of CSILs processed by CMS maintain as 94.87%. The adsorption isotherm and kinetics fitting demonstrate that vanadium (V) adsorption by two CSILs is dominated by chemisorption as a single molecular layer. Additionally, the adsorption reaction of vanadium (V) by these two CSILs are both endothermic, and entropy increases. Fourier transform infrared, scanning electron microscopy, and energy spectrometry analyses prove that PS[C₄mim][NO₃] is successfully prepared by UI and CMS methods, and ultrasound waves will not destroy the intact spherical structure of the support resins. The current work provides a novel insight for the efficient synthesis of CSILs, which is also a potential technique for improving the adsorption performance of the adsorbents towards valuable metals. Full article

The removal of the As(V) and Iprodione fungicide onto EGS@APTES-GT, obtained by amino-modified expanded glass spheres (EGS) modified with goethite, was studied in this work. Material characterization was performed using SEM/EDS, XRD, and FTIR techniques. The adsorption capacities of 51.01 and 94.28 mg g⁻¹, for As(V) and Iprodione removal at 25 °C, respectively, were achieved. A kinetic study indicated lower intraparticle diffusional transport resistance. Physisorption is the dominant mechanism for Iprodione removal, while surface complexation is for As(V). The disposal of effluent water after five adsorption–desorption cycles was attained through Iprodione photocatalytic degradation and arsenate precipitation. Exhausted EGS@APTES-GT, processed by goethite acidic dissolution and grinding, was used as a reinforcing filler in composites production based on commercial unsaturated polyester resin (UPe). An improvement in the mechanical properties was observed, with a gradual increase in the tensile strength, reaching a maximum of 25.9% for UPe with 10 wt.% of ground exhausted adsorbent compared to pure UPe. The overarching concept is defined by the aspiration to develop technologies that address all output flows of advanced processes. Thus, the combination of wastewater treatment technologies and the production of potentially marketable composites successfully achieved both a low environmental impact and the implementation of a circular economy. Full article

The comonomer bisphenol A (BPA) finds applications in the plastics industry, where it is used in the production of polycarbonates, plastics, PVC, thermal paper, epoxy and vinyl ester resins, and polyurethane. The water, with which many of these materials come into contact, is one of the main sources of human exposure to BPA. When ingested or touched, BPA can damage organs, disrupt the endocrine and immune systems, generate inflammatory responses, and be involved in genotoxic processes. Therefore, the need to develop effective techniques for removing BPA from aqueous environments is imperative. This paper provides a comprehensive review regarding the effective removal of BPA from water, focusing on the performance and adsorption mechanisms of various adsorbents based on chitosan and chitosan composites. The chemical and physical factors, adsorption kinetics and models governing the adsorption process of BPA in chitosan materials are also examined. This review outlines that, despite considerable progress in the absorption of bisphenol using chitosan gels, further research is necessary to assess the efficacy of these adsorbents in treating real wastewater and in large-scale manufacture. Full article

During oilfield production, organic substances such as asphaltenes and resins present in crude oil are prone to adsorb onto the surfaces of reservoir rocks. This adsorption process can lead to the conversion of hydrophilic rock surfaces into more oleophilic interfaces, which in turn reduces the permeability and porosity of the reservoir, ultimately affecting the overall recovery efficiency. Consequently, targeted modification of reservoir wettability presents a promising strategy for enhancing recovery rates. In this study, a polymer layer comprising large molecular side chains and hydroxyl groups was synthesized on the surface of nano-SiO₂ to enhance the thermal stability of the polymer. Additionally, the hydroxyl groups were employed to improve the wettability of the core material and reduce interfacial tension. The polymers were characterized using techniques such as FTIR and TG, and the results revealed that the modified SiO₂ exhibited superior performance in reducing both interfacial tension and contact angle when compared to the SiO₂. Injection of a 0.4 wt% EP-HMTA-SiO₂ solution resulted in an increase in recovery rates by 16.4% and 13.2% in medium- and low-permeability cores, respectively. Full article

In general, patients’ opinions on reaching ideal esthetics while restoring dental tissues is one of the most important part of the oral treatment. Unfortunately, discoloration of dental materials may occur due to intrinsic and extrinsic factors. The aim of the study was to evaluate the color stability of frequently used dental resin materials and determine the mechanism of their discoloration. The study used various characterization techniques (optical microscopy, Fourier-transform infrared spectroscopy, low-temperature N₂ adsorption, diffuse reflectance spectroscopy, and luminescence) to understand the effect of surface defects on discoloration. The adsorption of model liquids on the surface was confirmed to be related to the increase in BET surface area. The study found that the adsorption of discolorants, such as coffee, tea, and wine, on the surface of the dental material follows the multilayer BET model. When the surface is smooth, the discoloration is usually within acceptable limits, with a maximum of ∆E = 3.3. The discoloration made by tea and demineralized water was within acceptable limits even after 7 days of exposure. Full article

Tea saponins have high surface-active and biological activities and are widely used in chemicals, food, pharmaceuticals, and pesticides. Tea saponins are usually extracted using ethanol or water, but both methods have their disadvantages, including a negative impact on the environment, high energy consumption, and low purity. In this study, we explored an effective process for extracting tea saponins from tea meal using deep eutectic solvents combined with ultrasonic extraction and enzymatic techniques. The experimental results showed that a high extraction efficiency of 20.93 ± 0.48% could be achieved in 20 min using an ultrasonic power of 40% and a binary DES consisting of betaine and ethylene glycol (with a molar ratio of 1:3) at a material–liquid ratio of 1:35 and that the purity of the tea saponins after purification by a large-pore adsorption resin reached 95.94%, which was higher than that of commercially available standard tea saponin samples. In addition, the extracted tea saponins were evaluated for their antioxidant and bacteriostatic activities using chemical and biological methods; the results showed that the tea saponins extracted using these methods possessed antioxidant properties and displayed significant antibacterial activity. Therefore, the present study developed a method for using deep eutectic solvents as an environmentally friendly technological solution for obtaining high-purity tea saponins from tea meal oil. This is expected to replace the current organic solvent and water extraction process and has great potential for industrial development and a number of possible applications. Full article

Hydrometallurgical gold recovery processes play a pivotal role in the gold mining industry, contributing to more than 90% of global gold production. Among the array of techniques available, the Merrill–Crowe process, adsorption, ion exchange, and solvent extraction are central in extracting gold from leach solutions. While the Merrill–Crowe process and gold complex adsorption onto activated carbon represent historical cornerstones, their inherent limitations have prompted the emergence of more recent innovations in ion exchange and solvent extraction, offering enhanced selectivity, control, and sustainability. The evolution of modern organic chemistry has significantly influenced the progress of ion exchange technology, mainly through the introduction of advanced polymer matrix synthetic resins. At the same time, novel solvents tailored to gold complex interactions have revitalized ion exchange and solvent extraction. Introducing ionic liquids and deep eutectic solvents has also added a new dimension to efforts to improve gold extraction metallurgy. This paper reviews these cutting-edge developments and their potential to revolutionize the hydrometallurgical gold recovery process, addressing the pressing need for improved efficiency and environmental responsibility. Full article

This research presents a new, eco-friendly, and swift method combining solid-phase extraction and hydrophobic deep eutectic solvents (DES) with high-performance liquid chromatography (SPE-DES-HPLC) for extracting and quantifying catechin and epicatechin in Shanxi aged vinegar (SAV). The parameters, such as the elution solvent type, the XAD-2 macroporous resin dosage, the DES ratio, the DES volume, the adsorption time, and the desorption time, were optimized via a one-way experiment. A central composite design using the Box–Behnken methodology was employed to investigate the effects of various factors, including 17 experimental runs and the construction of three-dimensional response surface plots to identify the optimal conditions. The results show that the optimal conditions were an HDES (tetraethylammonium chloride and octanoic acid) ratio of 1:3, an XAD-2 macroporous resin dosage of 188 mg, and an adsorption time of 11 min. Under these optimal conditions, the coefficients of determination of the method were greater than or equal to 0.9917, the precision was less than 5%, and the recoveries ranged from 98.8% to 118.8%. The environmentally friendly nature of the analytical process and sample preparation was assessed via the Analytical Eco-Scale and AGREE, demonstrating that this method is a practical and eco-friendly alternative to conventional determination techniques. In summary, this innovative approach offers a solid foundation for the assessment of flavanol compounds present in SAV samples. Full article

In the quest to mitigate carbon dioxide emissions, it becomes essential to address the existing atmospheric CO₂. Effective and economical methodologies, particularly those without additional energy consumption, are crucial. Currently, a leading method is the direct capture of CO₂ using ion exchange resins, which achieve the adsorption and desorption of carbon dioxide simply by using the humidity variations. This technology, though minimizing additional energy cost, still needs improvement in its efficiency in CO₂ capture capacity and compared to other methods. In this work, we develop low-cost techniques to reduce the AmberLite™ IRA900 Cl (IRA-900) anion exchange resin to micro size, and observe significant performance enhancement on CO₂ capture efficiency contingent on reducing the particle diameters. This performance disparity is attributed to the differential water adsorption capacities inherent in particles of diverse diameters. Our results reveal that smaller resin particles outperform their larger counterparts, exhibiting accelerated adsorption rates and expedited transitions from wet to dry states. Notably, these smaller particles display a quintupled enhancement in adsorption efficacy relative to non-treated particles and a marked increase in relative adsorption capacity. Upon treatment, IRA-900 demonstrates robust CO₂ processing efficiency, achieving a peak adsorption rate of 1.28 g/mol·h and a maximum desorption rate of 1.18 g/mol·h. Also, the material is subjected to almost 100 cycles of testing, and even after 100 cycles, the resin particles maintain a capacity of 100%. Moreover, our material can be fully regenerated to 100% efficiency by simply immersing it in water. Simultaneously, storing it in water allows for the long-term maintenance of its performance without other treatment methods. A key observation is the resin’s sustained performance stability post extended exposure to humid conditions. These outcomes offer substantial practical implications, emphasizing the relevance of our study in practical environmental applications. Full article