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Nitridophosphates have emerged as promising host compounds in the field of solid‐state lighting. Their industrial relevance has increased significantly, mainly due to recent advances in synthetic approaches under medium‐pressure (MP) conditions, including ammonothermal synthesis and hot isostatic pressing (HIP). In this study, we report on the synthesis and characterization of the quaternary representatives CaxLi10−2xP4N10 (x=2, 2.7, 4) and Sr3Li4P4N10, prepared via a simplified ion exchange reaction under MP conditions, starting from the nitridophosphate‐based lithium ion conductor Li10P4N10. The synthesis route allowed for the preservation of the anionic [P4N10]10− structural motif of the starting material, while simultaneously introducing potential doping sites for Eu2+ by incorporating divalent alkaline earth cations (Ca2+/Sr2+). Upon excitation of Eu2+ doped samples with blue light, strong luminescence due to parity‐allowed 4f6(7F)5d1→4f7(8S7/2) transition can be observed in the red (Ca2Li6P4N10 : Eu2+: λmax=626 nm), yellow/orange (Ca2.7Li4.6P4N10 : Eu2+: λmax1=506 nm, λmax2=592 nm and Sr3Li4P4N10 : Eu2+: λmax=596 nm) and green (Ca4Li2P4N10 : Eu2+: λmax=546 nm) spectral regions of the visible light. The compounds presented, together with the simplified synthetic approach, demonstrate the significant potential of ion exchange on Li ion conductors for the development of novel nitridophosphates in the future. [ABSTRACT FROM AUTHOR]

Lithium disilicate (LD) glass-ceramics used for bone repair need to have good mechanical properties and biological activity. Ion-exchange can lead a significant surficial strengthening and bioactivity of LD glass-ceramics. In this work, LD glass-ceramics were Li+/Ca2+@Li+/K+ exchanged in a mixed salt bath of 30 % Ca(NO 3) 2 + 70 % KNO 3 (in mol %) at 400 °C for 16 h, 32 h and 64 h respectively. LD glass-ceramics were significantly strengthened after Li+/Ca2+@Li+/K+ exchange. However, due to the shallow depth of the ion-exchange layer and stress relaxation, the strengthening effect deteriorated with the prolongation of the ion-exchange time. The Li+/Ca2+@Li+/K+ exchanged LD glass-ceramics could be conducive to the formation of the hydroxyapatite (HA) after soaking in the simulated body fluid (SBF). Moreover, the protein adsorption, cytotoxicity, cell adhesion, osteoblast proliferation and alkaline phosphatase (ALP) activity expression of Li+/Ca2+@Li+/K+ exchanged LD glass-ceramics were investigated. Ca2+ release might promote the bioactivity of ion-exchanged LD glass-ceramics. Therefore, Li+/Ca2+@Li+/K+ exchange can improve the mechanical properties and bioactivity of LD glass-ceramics, which has important significance for its application in orthopedic reconstruction. [ABSTRACT FROM AUTHOR]

MgO-Al 2 O 3 -SiO 2 -ZnO-TiO 2 -ZrO 2 glass with the addition of 8 mol% Na 2 O as flux has been prepared by the melt-casting method, and transparent glass-ceramics (GCs) with spinel (MgAl 2 O 4 and ZnAl 2 O 4) as the main crystalline phases were prepared by controlled crystallization. The optimum nucleation temperature was determined through DSC method, which is conducted on the glass with different preheating temperatures. The type and size of crystals in MAS glass-ceramics are highly dependent on the heat treatment. As the nucleation time increased to over 25 h, the formation of spinel was hindered due to the increasing formation of Na 2 TiSiO 5 in the glass, which consumed most of the Ti4+ ions during the long-term nucleation. When the nucleation time is up to 35 h, there is only Na 2 TiSiO 5 crystalline phase in the GCs. The nucleation time have a significant effect on the ion-exchange process through changing the crystals type and microstructure of GC. Both the Na + ions in Na 2 TiSiO 5 crystals and glassy phase can participate ion-exchange with K+ ions in molten salts, facilitating to form compressive stress. While, the formation of spinel consumed a lot of [AlO 4 ] in glassy phase, which decreasing the ion-exchange channel and thus hindering the ion-exchange. When heat treated at 700 °C/25 h + 830 °C/1 h, the MAS glass-ceramic showed transparency over 78 % at 550 nm, and its Vickers hardness reached ∼845 kgf/mm2 after ion-exchange. [ABSTRACT FROM AUTHOR]

Inert gas argon has important applications in the fields of daily life, industrial manufacture and nuclear environmental monitoring. The key to its application is to selectively and efficiently separate and purify Ar from complex gas components. However, the separation of O2 and Ar at normal temperature is full of challenge due to their similar molecular sizes and adsorption properties as well as their close boiling point. In industry, high purity Ar is mainly produced by low temperature rectification, which is mature technology, but the equipment is large, high-energy consumption and explosive. Adsorption separation is a common method of gas separation. Molecular sieves are the most widely used material due to their huge specific surface area, aboudant pore structure and excellent adsorption properties. The silica tetrahedron in molecular sieve is electrically neutral, while the aluminum tetrahedron is electronegative, which makes it necessary to use H+ or Na+ outside the molecular sieve skeleton to maintain electrical neutrality. In actual application, the interaction between adsorbent and adsorbent can be enhanced by ion-exchange modification of molecular sieve material, so as to effectively improve the O2/Ar separation capacity of molecular sieve. In this paper, the application of ion-exchange modified molecular sieve materials in the field of O2/Ar adsorption separation was systematically summarized and reviewed. The results show that the O2/Ar separation coefficients of molecular sieves modified by alkaline earth metal ions like Ca2+, Sr2+ and Ba2+ can reach about 2.0, while that of Ce3+-exchanged X-type molecular sieve is as high as 5.9, it is an ideal adsorption material for O2/Ar separation. However, the high separation coefficient is limited to the range of low partial pressure, and the O2/Ar separation coefficient under normal pressure is below 2.0. The Ag+-exchanged molecular sieves, namely silver-loaded molecular sieves, have excellent Ar adsorption selectivity. At present, the O2/Ar separation coefficients of silver-loaded molecular sieve materials at atmospheric pressure are around 2.0, but the preparation cost of silver-loaded molecular sieves is high, and it is more suitable for small-scale separation applications, it means that the efficient separation of O2 and Ar at normal temperature and pressure is still challenging. The development of novel ion-exchange modified molecular sieve materials with high adsorption capacity and high adsorption selectivity for the separation of O2 and Ar is still one of the focuses and trends of future research projects.

Transparent glass–ceramics (GCs) with excellent mechanical properties is a growing demand in the field of optoelectronic devices. In this work, Mg2SiO4 nanocrystals embedded transparent GCs were prepared using the melt‐quenching method. The effects of the TiO2 content on the structural and crystallization properties of glass were examined, and the influence of Mg2SiO4 crystallization on the depth of layer (DOL) for K–Na ion‐exchange was also investigated. The introduction of TiO2 was advantageous for the enhanced bulk crystallization of Mg2SiO4 nanocrystals within the glass matrix. With an increase in the TiO2 content, the size of Mg2SiO4 nanocrystals decreased, leading to an improvement in the transmittance of the GCs. Crystallization of Mg2SiO4 nanocrystals promoted the increase in Vickers hardness and ion‐exchange DOL obviously, and the Vickers hardness can further be improved by ion‐exchange. Ion‐exchange resulted in the transformation of NaAlSiO4 into KAlSiO4. Results reported here are valuable for the design and preparation of GCs with excellent mechanical and ion‐exchange properties. [ABSTRACT FROM AUTHOR]

Methods for obtaining high-purity perrhenic acid (with metallic impurities content below 100 ppm) of a high concentration > 200 g/dm3 and entirely from secondary raw materials were compared. Comparative analyses of three methods were performed: electrodialysis, solvent extraction (research carried out directly as part of the Small Grant project acronym RenMet), and ion-exchange (developed as part of previous projects implemented by Łukasiewicz-IMN). The basic process parameters were selected as comparative indicators: efficiency and selectivity of the process, purity of the obtained product, availability and consumption of raw materials and reagents, equipment necessary to carry out the process, the profitability of the technology, and the ecological aspects, i.e., the possibility of managing the generated solid waste and post-production solutions. Analysis of the verified indicators allowed us to select the most economically and ecologically advantageous method of obtaining high-purity perrhenic acid from secondary raw materials. Its preparation using the ion-exchange method emphasizes the product's purity and the process's simplicity, using readily available waste materials and renewable ion-exchange resin, and is based on a sustainable circular economy. [ABSTRACT FROM AUTHOR]

Miniature spectrometer is powerful tool for scientific research and industrial inspection. Here, we report the fabrication of graded perovskite filters with tunable bandgap and their application in constructing miniature spectrometer. The graded perovskite filters were fabricated using a Finkelstein reaction between in-situ formed halogen ion with a preformed MAPbX3 film. The graded bandgap of perovskite films can be well tunned from 400 to 750 nm by controlling the volume ratio between 5,5-dimethyl-1-pyrroline N-oxide and benzyl chloride(bromide). By combining a deep residual network, graded bandgap perovskite film and commercial CMOS sensor chip, a miniature spectrometer is demonstrated, achieving an accurate spectrum reconstruction (PSNR = 40.749) with monochromatic spectral resolution of 1.31 nm. [ABSTRACT FROM AUTHOR]

As a critical radioactive anionic contaminant, traditional adsorbents primarily remove iodate (IO3−) through ion exchange or hard acid‐hard base interactions, but suffer from limited affinity and capacity. Herein, employing the synergistic effect of ion exchange and redox, we successfully synthesized a redox‐active cationic polymer network (SCU‐CPN‐6, [C9H10O2N5 ⋅ Cl]n) by merging guanidino groups with ion‐exchange capability and phenolic groups with redox ability via a Schiff base reaction. SCU‐CPN‐6 exhibits a groundbreaking adsorption capacity of 896 mg/g for IO3−. The inferior adsorption capacities of polymeric networks containing only redox (~0 mg/g) or ion exchange (232 mg/g) fragments underscore the synergistic "1+1>2" effect of the two mechanisms. Besides, SCU‐CPN‐6 shows excellent uptake selectivity for IO3− in the presence of high concentrations of SO42−, Cl−, and NO3−. Meanwhile, a high distribution coefficient indicates its exemplary deep‐removal performance for low IO3− concentration. The synergic strategy not only presents a breakthrough solution for the efficient removal of IO3− but also establishes a promising avenue for the design of advanced adsorbents for diverse applications. [ABSTRACT FROM AUTHOR]

Over the past decade, using liquid digestate as a nutrient source for microalgae cultivation has gained considerable attention. However, its high ammonium concentration and turbidity often inhibit algal growth. To address this, natural zeolite was explored as a novel approach to reduce digestate toxicity before microalgae cultivation at both laboratory and pilot-scales. Clinoptilolite, a type of natural zeolite, was applied in adsorption columns at a ratio of 0.5 kgzeolite.L-1 to treat 0.45 L of liquid digestate. After 24 h of treatment, ammonium levels decreased significantly from 2273 to 115 mgN.L-1, corresponding to a 95 % removal efficiency and an adsorption capacity of 4.31 mg.gzeolite-1. Arthrospira platensis demonstrated strong growth in the treated digestate with minimal dilution (≤5x), in contrast to the high dilution (≥20x) required for the untreated digestate. Laboratory-scale results were effectively scaled up to pilot scale, detoxifying 15.5 L of digestate with similar performances. The pretreated digestate was subsequently used as a culture medium for Arthrospira platensis in flat panel photobioreactors without further dilution, achieving a final concentration of 0.82 gDW.L-1 and a biomass productivity of 33 mg.L-1.d-1. These findings underscore the potential of natural zeolite in enhancing microalgae-based processes for digestate detoxification and CO2 mitigation.

Zeolitic materials enriched in phosphorus and nitrogen, with a pronounced content for this last element, were obtained from natural clinoptilolite (CLI) treated with ammonium hydrogenphosphate (DAP) and urea. The interaction of phosphorus and nitrogen species retained on CLI was analyzed using different research methods. FTIR spectra showed the presence of NH4+, PO43− and urea on CLI. The retention of ammonium involves both ion-exchange in clinoptilolite, and adsorption. Phosphate is retained by adsorption, and it can be incorporated into an electrical double layer with accompanying cations including NH4+. The FTIR bands of the amino group of urea appear to be shifted relative to their location in the urea spectrum. This is associated with weakening of N–H bond from amino group due to its interaction with the clinoptilolite framework via hydrogen bonding. The urea is arranged on the zeolite surface, which is consistent with SEM observations and elemental (N and P) mapping by STEM. As a result, the surface area and micropore volume of these materials, treated with DAP and urea, decrease with respect to those modified with DAP alone. Accordingly, the release studies showed that the subsequent delivery of phosphorus species occurs in a delayed mode. These materials have great potential to be used as slow-release nutrient fertilizers for crop plants. They have a significant amount of nitrogen available on their surface, allowing plants to easily assimilate it early in their growing cycle. Zeolitic matrix leads to obtain materials at low-cost for massive applications, efficient use of nutrients and environmental benefits. [ABSTRACT FROM AUTHOR]

Today, ion‐exchanged or chemically strengthened glass is ubiquitously used all over the world, typically for scratch‐free display cover of personal mobile phones. It has been known that the strengthening is due to developments of high compressive stress in the surface layer by its internally constrained dilation. We investigated micro‐scale mechanical properties of the surface layer itself of a Na+‐to‐K+ ion‐exchanged soda lime silicate glass, revealing that the strength of the layer increased nearly 40% by the ion‐exchange with little compression effect from the interior. The fracture toughness, however, was comparable before and after the ion‐exchange, indicating that the ion‐exchange reduces the crack size of the fracture origin. Theoretical estimates of fracture surface energies verified the measured fracture toughness. It was presumed that the observed crack‐size reduction is due to crack healing effects enhanced by the ion‐exchange. [ABSTRACT FROM AUTHOR]

Zinc magnesium aluminosilicate (ZMAS) glasses were obtained with the addition of Na2O (from 1.1 to 7.0 mol.%). The influence of the Na2O content on glass forming ability and effectiveness of the ion-exchange treatment in molten KNO3 was studied. The dependencies of depth and stress of subsurface layer on treatment duration were also studied along with an evaluation of the concentration shifts of alkaline cations in result of ion-exchange process. It is shown that glass Vickers hardness increases both with the Na2O content in glass and with the duration of ion-exchange. Vickers hardness of the ion-exchanged glasses with 7 mol.% of Na2O treated duration for 72 h reaches 900 HV. The possibility of using an ion-exchange process with glass-ceramics obtained from glasses of ZMAS system modified with sodium oxide is discussed. [ABSTRACT FROM AUTHOR]

Alkali-aluminosilicate glass and glass-ceramics can be effectively strengthened by ion-exchange if compression is introduced into the surface, which have been widely used in many electronic devices, especially for mobile phones. In this work, the transparent lithium aluminosilicate glass-ceramics with eucryptite crystalline phase were ion-exchanged in the mixed x NaNO 3 + (100－ x) KNO 3 (wt %, x = 60, 70, 80, 90, 100) molten salts at 420 °C for 4 h. With the increase of NaNO 3 concentration in the molten salts from 60 to 100 wt %, the depth of stress layer increase from 98 to 104 μm, and the surface compressive stress increase to the maximum ∼500 MPa at x = 80 and then decrease. In addition, there is also a K+-rich layer observed with the depth of ∼25 μm. The ion-exchange takes place in both crystalline and residual glassy phases, and thus leads to the microstructural modifications, including the amorphization of eucryptite and the presence of lithium phosphate. Upon ion-exchange, the Vickers hardness of glass-ceramics increase from 7.03 GPa to the maximum ∼7.62 GPa (x = 80), and the bending strength from 198 MPa to the maximum ∼510 MPa (x = 90). The improvement in mechanical properties is mainly related to the generation of surface compressive stress layer. Meanwhile, the amorphization and transformation of crystalline phase during the ion-exchange process are probably conductive for the reduction of surface cracks and defects, leading to the enhancement of mechanical properties, especially for the bending strength. [ABSTRACT FROM AUTHOR]

Titanates are one of promising sorbents for toxic heavy metal ions and radionuclides due to various chemical formulas and crystal structures, and their functional properties. Herein, we present a unique seaweed-like sodium titanate mat (SST) with randomly distributed layered sodium dititanate nanofibers synthesized by a simple hydrothermal process. We focused on the effect of NaOH concentration during the hydrothermal process on crystallographic properties and investigated the synthesis conditions for SST. Furthermore, Sr2+ sorption properties of SST and related titanates, which were synthesized by hydrothermal process, was studied by batch tests. SST, which consist of a dititanate phase, was synthesized at 10 mol/L NaOH concentration and trititanate phase was formed when the NaOH concentration was increased to 15 mol/L. The SST showed a high ion-exchange selectivity of Sr2+ against H+ and a high maximum sorption capacity (2 mmol/g), compared with the case of trititanate phase (0.49 mmol/g), which shows the precipitation of SrCO3. This was presumably due to the difference of crystal structure of two titanates. This study demonstrates that the design of the crystal structure is important for controlling the sorption mechanism of sorbents for water treatment. [ABSTRACT FROM AUTHOR]

Ion-exchange membranes (AEMs) are extensively utilized in separation processes for the treatment of contaminated effluents and the removal of heavy metals. This study aimed to produce and characterize heterogeneous ion-exchange membranes using the phase inversion technique. Polysulfone and polyethersulfone polymer matrix membranes were prepared by incorporating Duolite AP143/1083 and AmberliteTM IRP69 resins into the anion and cation exchange membranes at a proportion of 5% (wt/wt). Additionally, the simultaneous incorporation of graphene oxide (GO) at 2.5% and 5.0% (wt/wt) with the resins was investigated. The membranes underwent characterization through permeability measurements, cross-sectional analysis, morphology examination, mechanical strength testing, and ion exchange capacity evaluation. The membranes displayed a maximum water permeability flux of 59.5 L h−1 m−2 bar−1, while the polyethersulfone with anion exchange resin and 2.5% graphene oxide (PESAOG2.5) and polyethersulfone with cation exchange resin and 2.5% graphene oxide (PESCOG2.5) membranes achieved fluxes of 20.81 and 16 L h−1 m−2 bar−1, respectively. The ion exchange indices for polysulfone membranes (PS) and polyethersulfone membranes (PES) membranes were 0.26 and 0.23 mmol/g, respectively, which increased with the incorporation of resins and GO, reaching 1.08 mmol/g in PESAOG2.5 membranes. The addition of GO demonstrated promising results in producing heterogeneous ion-exchange membranes with potential applications in the removal of metal ions from various contaminated effluents. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are a class of ubiquitous, persistent, and hazardous pollutants that raise concerns for human health and the environment. Typically, PFAS removal from water relies on adsorption techniques using conventional sorption materials like activated carbons (ACs) and ion exchange resins (IERs). However, there is a continuous search for more efficient and performing adsorbent materials to better address the wide range of chemical structures of PFAS in the environment, to increase their selectivity, and to achieve an overall high adsorption capacity and faster uptake kinetics. In this context, results from the application of non-conventional sorption materials (i.e., readily available biological-based materials like proteins and advanced materials like nanocomposites and cyclodextrins) are reported and discussed in consideration of the following criteria: i) removal efficiency and kinetics of legacy PFAS (e.g., PFOA, PFBA) as well as newly-introduced and emerging PFAS (e.g., GenX), ii) representativity of environmental conditions in the experimental setup (e.g., use of environmentally relevant experimental concentrations), iii) regenerability, reusability and applicability of the materials, and iv) role of the material modifications on PFAS adsorption. From this review, it emerged that organic frameworks, nano(ligno)cellulosic-based materials, and layered double hydroxides are among the most promising materials herein investigated for PFAS adsorption, and it was also observed that the presence of fluorine- and amine-moieties in the material structure improve both the selectivity and PFAS uptake. However, the lack of data on their applicability in real environments and the costs involved means that this research is still in its infancy and need further investigation.

Despite the outstanding features of the titanosilicate ETS-10 and some studies done on CO2 adsorption so far, there is a lack of coherent information to evaluate its potential industrial application in CO2 separation from natural gas and flue gas. In this work, ETS-10 and SrETS-10 were synthesized and characterized by PXRD, SEM, DTA, EDX, and BET. Pure gas adsorption isotherms of CO2, CH4, and N2 at 298 K were obtained by the constant-volume method. The obtained adsorption data were fitted with Langmuir and UNILAN isotherm models. The CO2/CH4 selectivity (yCO2 = 0.05) predicted by Ideal Adsorption Solution Theory (IAST) was 67.54 and 35.65 for ETS-10 and SrETS-10, respectively, while the CO2/N2 selectivity (yCO2 = 0.04) was 94.64 and 99.94. The Pseudo-Nth-Order (PNO) and micropore diffusion model were used to evaluate the CO2 adsorption kinetics and diffusivity of the adsorbents. The results showed that both ETS-10 and SrETS-10 exhibited fast kinetics for CO2 adsorption, but SrETS-10 had a slightly smaller diffusion coefficient (DC/rC2 = 0.01494 and 0.01458 s−1 for ETS-10 and SrETS-10, respectively) resulting in a slower adsorption rate than ETS-10. The regenerability of ETS-10 and SrETS-10 was studied and it was found that for ETS-10 about 79.07% and 96.32% of the capacity can be regenerated by applying vacuum and heating, respectively and also 79.67% of the SrETS-10 capacity can also be regenerated by applying vacuum. From the results of this work with an approach of industrial application, it was concluded that ETS-10 and SrETS-10 can be used in a combined PSA and TSA process for CO2 separation.

A process for dewatering spent ion exchange resins (gel and porous) used in nuclear power plants by supercritical CO2 (sCO2) is described. The amount of water removed by sCO2 is much higher than that expected from solubility considerations alone. Water from gel-type resins is both dissolved by and emulsified in sCO2. Emulsification also occurs in the absence of solids when water alone is contacted by sCO2. It is not a factor for microporous resins where an additional mechanism, viscous fingering, is involved. It appears that bulk water is emulsifiable but not if it is held in pores. Dewatering via viscous fingering has been previously invoked for matrices such as wood and sludge. The resins can be dewatered and dried with sequential batches of sCO2 at sub-boiling temperatures. The CO2 can then be potentially reused after expansion and separation from the entrained water. Partial decompression of the water-laden sCO2 would lead to cooling, which would drop the water solubility substantially. A reduction of temperature from 90 oC to 65oC reduces the solubility of water in sCO2 by a factor of five. The condensed water could then be separated with a hydrocyclone. The footprint of sCO2 is much smaller than the conventional drying process. The energy costs are also much lower because evaporation of water is avoided. [ABSTRACT FROM AUTHOR]

A process for dewatering spent ion exchange resins (gel and porous) used in nuclear power plants by supercritical CO2 (sCO2) is described. The amount of water removed by sCO2 is much higher than that expected from solubility considerations alone. Water from gel-type resins is both dissolved by and emulsified in sCO2. Emulsification also occurs in the absence of solids when water alone is contacted by sCO2. It is not a factor for microporous resins where an additional mechanism, viscous fingering, is involved. It appears that bulk water is emulsifiable but not if it is held in pores. Dewatering via viscous fingering has been previously invoked for matrices such as wood and sludge. The resins can be dewatered and dried with sequential batches of sCO2 at sub-boiling temperatures. The CO2 can then be potentially reused after expansion and separation from the entrained water. Partial decompression of the water-laden sCO2 would lead to cooling, which would drop the water solubility substantially. A reduction of temperature from 90 oC to 65oC reduces the solubility of water in sCO2 by a factor of five. The condensed water could then be separated with a hydrocyclone. The footprint of sCO2 is much smaller than the conventional drying process. The energy costs are also much lower because evaporation of water is avoided. [ABSTRACT FROM AUTHOR]

The fabrication of structured zeolite adsorbents through photopolymerization‐based 3D printing which offers a solution to the limitations of conventional shaping techniques has been demonstrated but many parameters still need to be optimized. In this study, we studied the influence of zeolite compensation cations on the photopolymerization and the composite's properties. Modified zeolites (LTA 4 A and FAU 13X exchanged with K+, Li+, Sr2+, Ca2+ or Mg2+) were incorporated in PEGDA with BDMK as photoinitiator, and the formulation was cured under mild conditions (LED@405 nm, room temperature, under air). Our results indicate that the nature of zeolite compensation cations affects the colorimetric properties of polymer/zeolite composites: a better translucency parameter results in higher depth of cure. After calcination at 650 °C and complete removal of PEGDA, pure zeolitic monoliths were tested for adsorption of gas molecules of interest (carbon dioxide, dichlorobenzene and water). Structured 4 A and 13X monoliths obtained by 3D printing exhibit comparable adsorption capacity to commercial beads prepared from the same zeolites. This study enhances our understanding of the photopolymerization process involved in the production of polymer/zeolite composites. These composites are used in the fabrication of zeolitic objects through 3D printing, offering potential solutions to various environmental and dental challenges. [ABSTRACT FROM AUTHOR]

Lithium disilicate (LD) glass-ceramics have adequate mechanical properties and are considered as a candidate for repairing large bone defects. However, LD glass-ceramic is an inherently inert restorative material, which cannot induce new bone tissue. In the present study, LD glass-ceramics were ion-exchanged at 235 °C for 16 h, 64 h and 128 h in a mixed salt bath of sodium nitrate and potassium nitrate (1:1 M ratio) respectively. A gradient concentration distribution of Na+-rich layer was obtained by Li+/Na+ exchange and Na+ ions were released from the Li+/Na+ exchanged LD glass-ceramics in an aqueous condition. The hydroxyapatite (HA) layer was formed on Li+/Na+ exchanged LD glass-ceramic and exhibited a significant exchange time-dependent after soaking in the simulated body fluid (SBF). Moreover, the Li+/Na+ exchange treatment could improve cell adhesion, proliferation and osteogenic differentiation of LD glass-ceramic significantly, and long-time treatment could achieve a better performance. Therefore, ion-exchange process is a feasible strategy to promote the surface biomineralization, cytocompatibility and osteogenesis of LD glass-ceramics. These results suggest that Li+/Na+ exchange is a promising process for LD glass-ceramic application in clinical orthopedic reconstruction. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn/δ‐MnO2 batteries are extensively investigated owing to the low cost, safety and eco‐friendliness. However, the charge storage mechanism of δ‐MnO2 electrode is still in debate. In this paper, it is revealed that the Zn2+ intercalation in δ‐MnO2 electrode is an ion exchange process rather than the commonly‐conceived electrochemical process for the first time. Before the discharge/charge process, Zn2+ irreversibly intercalates into the structure of δ‐MnO2. The ion‐exchange mediated irreversible Zn2+ intercalation in δ‐MnO2 has no contribution to the capacity of δ‐MnO2 electrode during cycles. This study further reveals that the electrochemical H+ intercalation/extraction, the electrodissolution of δ‐MnO2 and the electrodissolution‐electrodeposition of vernadite dominate the charge storage process of δ‐MnO2 electrode. These findings shed new light on the fundamental understanding for the reaction mechanism of δ‐MnO2 electrode in aqueous batteries. [ABSTRACT FROM AUTHOR]

Internal microtextures of ternary alkali feldspars in sanidine trachyte from Oki‐Dogo Island were examined using an electron microprobe analyzer, a scanning electron microscope, a transmission electron microscope and cathodoluminescence instruments, to develop the understanding of volcanic processes of alkaline magmas related to feldspar crystallization. The examined trachyte is an evolved rock of the Oki‐Dogo Pliocene trachyte group. Its phenocryst feldspars are commonly associated with lamellar‐wavy‐domain textures with scales approximately from 100 nm up to several hundreds of μm that show complex and gradual variations in composition: however, anti‐rapakivi zoning textures common in other Oki‐Dogo alkaline rocks are almost completely absent in the trachyte. These textures are produced by extensive magmatic ion‐exchange replacement reactions progressively advanced in the evolved magma. Characteristic braided fluorite alignments are developed consistently with lamellar‐wavy‐domain textures in phenocryst feldspars, and similar braided alignments are also present in groundmass feldspars with complicated microtextures. Most of fluorite grains are <100 nm in diameter, and the patterns of braided fluorite alignments vary greatly in individual feldspars. The whole occurrence of the feldspar microtextures represents an extreme example of diffusion‐controlled replacement reactions, progressively advanced in the dry (relatively anhydrous) trachyte magma. The genetic processes forming fluorite alignments in feldspars are related to magma compositions, especially F and P contents, and the crystallization of F‐bearing minerals, especially of fluorapatite. [ABSTRACT FROM AUTHOR]

The name "chromatography" comes from the Greek words "graphien," which means to write, and "chroma," which means color. One method of separating components in a mixture is chromatography. The mixture's constituent parts are distributed throughout a liquid solution known as the mobile phase, which retains them inside a framework made of a different material known as the stationary phase. Differential partitioning between the mobile and stationary phases is necessary for component separation. Chromatography is mostly used to extract and purify one or more sample components. Its analytical objective is to ascertain the qualitative and quantitative chemical composition of a sample. It is the fastest, most trustworthy, safest, and most adaptable technology for ensuring the quality of medicinal ingredients. While basic chromatography still prevails as the most important analytical tools in molecular chemistry. This paper will discuss overview, principle, types and applications of different chromatography techniques. [ABSTRACT FROM AUTHOR]

Ion-exchange reactions are commonly used to develop novel metastable electrode materials for alkali-ion batteries that cannot be synthesized using direct chemical reactions. In this study, the electrochemical K to Na ion-exchange reaction mechanisms in a layered KxCoO2 cathode as a model system were investigated using operando and ex situ structure characterization techniques. Some level of K ions was observed to remain in the layered structure during the electrochemical ion-exchange reactions. Interestingly, the K ions are well separated from the Na-rich phases in the discharged state, and they form an intermediate phase in which K and Na ions are mixed at the top of charge. We discovered that such residual K ions prevent the collapse of the layered structure in the high-voltage regime, thereby improving the cycling stability in a Na-battery system.

Modified or low-salinity waterflooding of carbonate oil reservoirs is of considerable economic interest because of potentially inexpensive incremental oil production. The injected modified brine changes the surface chemistry of the carbonate rock and crude oil interfaces and detaches some of adhered crude oil. Composition design of brine modified to enhance oil recovery is determined by labor-intensive trial-and-error laboratory corefloods. Unfortunately, limestone, which predominantly consists of aqueous-reactive calcium carbonate, alters injected brine composition by mineral dissolution/precipitation. Accordingly, the rock reactivity hinders rational design of brines tailored to improve oil recovery. Previously, we presented a theoretical analysis of 1D, single-phase brine injection into calcium carbonate-rock that accounts for mineral dissolution, ion exchange, and dispersion (Yutkin et al. in SPE J 23(01):084–101, 2018. https://doi.org/10.2118/182829-PA). Here, we present the results of single-phase waterflood-brine experiments that verify the theoretical framework. We show that concentration histories eluted from Indiana limestone cores possess features characteristic of fast calcium carbonate dissolution, 2:1 ion exchange, and high dispersion. The injected brine reaches chemical equilibrium inside the porous rock even at injection rates higher than 3.5 × 10- 3 m s- 1 (1000 ft/day). Ion exchange results in salinity waves observed experimentally, while high dispersion is responsible for long concentration history tails. Using the verified theoretical framework, we briefly explore how these processes modify aqueous-phase composition during the injection of designer brines into a calcium-carbonate reservoir. Because of high salinity of the initial and injected brines, ion exchange affects injected concentrations only in high surface area carbonates/limestones, such as chalks. Calcium-carbonate dissolution only affects aqueous solution pH. The rock surface composition is affected by all processes.

Methods for obtaining high-purity perrhenic acid (with metallic impurities content below 100 ppm) of a high concentration > 200 g/dm3 and entirely from secondary raw materials were compared. Comparative analyses of three methods were performed: electrodialysis, solvent extraction (research carried out directly as part of the Small Grant project acronym RenMet), and ion-exchange (developed as part of previous projects implemented by Łukasiewicz-IMN). The basic process parameters were selected as comparative indicators: efficiency and selectivity of the process, purity of the obtained product, availability and consumption of raw materials and reagents, equipment necessary to carry out the process, the profitability of the technology, and the ecological aspects, i.e., the possibility of managing the generated solid waste and post-production solutions. Analysis of the verified indicators allowed us to select the most economically and ecologically advantageous method of obtaining high-purity perrhenic acid from secondary raw materials. Its preparation using the ion-exchange method emphasizes the product’s purity and the process’s simplicity, using readily available waste materials and renewable ion-exchange resin, and is based on a sustainable circular economy.

IntroductionSilver-releasing dressings are used in the treatment of infected wounds. Despite their widespread use, neither the amount of silver released nor the potential in vivo toxicity is known. The aim of this study was to evaluate the cytotoxic effects and the amount of silver released from commercially available dressings with infected wounds.MethodsThe review was conducted according to the PRISMA statement. The Web of Science, PubMed, Embase, Scopus, and CINAHL databases were searched for studies from 2002 through December 2022. The criteria were as follows: population (human patients with infected wounds); intervention (commercial dressings with clinical silver authorized for use in humans); and outcomes (concentrations of silver ions released into tissues and plasma). Any study based on silver-free dressings, experimental dressings, or dressings not for clinical use in humans should be excluded. According to the type of study, systematic reviews, experimental, quasi-experimental, and observational studies in English, Spanish, or Portuguese were considered. The quality of the selected studies was assessed using the JBI critical appraisal tools. Studies that assessed at least 65% of the included items were included. Data were extracted independently by two reviewers.Results740 articles were found and five were finally selected (all of them quasi-experimental). Heterogeneity was found in terms of study design, application of silver dressings, and methods of assessment, which limited the comparability between studies.ConclusionIn vivo comparative studies of clinical dressings for control of infection lack a standardized methodology that allows observation of all the variables of silver performance at local and systemic levels, as well as evaluation of its cytotoxicity. It cannot be concluded whether the assessed concentrations of released silver in commercial dressings for the topical treatment of infected wounds are cytotoxic to skin cells.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022351041, PROSPERO [CRD42022351041].

The remote villages in arid and semi-arid inland regions of Rajasthan state in India and many other countries are dependent on brackish groundwater for potable uses. Generally, community RO (Reverse Osmosis) plants are installed for brackish water treatment in rural agglomerations where the MLD (Minimal liquid discharge) scheme is followed which includes pre-treatment and pre-concentration technologies, that consumes relatively low energy than thermal technologies for ZLD (Zero liquid discharge). This paper discusses the application of hybrid processes involving MLD technologies such as IEX (Ion Exchange), NF (Nanofiltration), RO, FO (Forward Osmosis) and UF (Ultrafiltration). for brackish water treatment. The impact of feed water quality and operational parameters such as flux, feed flow rate and transmembrane pressure are discussed. Further, performance indicators such as salt rejection, recovery, energy consumption and scaling propensity are discussed to evaluate the feasibility of various configurations. The findings of this review indicate NF as impressive membrane technology for conjunction with IEX, RO and UF. Further, the use of FO or NF as a pre-treatment for RO has been found to reduce the scaling propensity of RO membranes; and the use of UF as a pre-treatment for NF has been found to reduce the propensity of organic fouling on NF membranes. Also, IEX as a pre-treatment can be coupled with low-pressure RO/NF to remove the scale-causing divalent ions and enhance recovery along with an option of reusing RO/NF reject water for regeneration of IEX column. [ABSTRACT FROM AUTHOR]

[Display omitted] Herein, a well-designed hierarchical architecture of bimetallic transition sulfide FeIn 2 S 4 nanoparticles anchoring on the Ti 3 C 2 MXene flakes has been prepared by cation exchange and subsequent high-temperature sulfidation processes. The introduction of MXene substrate with excellent conductivity not only accelerates the migration rate of Na+ to achieve fast reaction dynamics but provides abundant deposition sites for the FeIn 2 S 4 nanoparticles. In addition, this hierarchical structure of MXene@FeIn 2 S 4 can effectively restrain the accumulation of MXene to guarantee the maximized exposure of redox active sites into the electrolyte, and simultaneously relieve the volume expansion in the repeated discharging/charging processes. The MXene@FeIn 2 S 4 displays outstanding rate capability (448.2 mAh g−1 at 5 A g−1) and stable long cycling performance (428.1 mAh g−1 at 2 A g−1 after 200 cycles). Moreover, the Na y -In 6 S 7 phase detected by ex-situ XRD and XPS characterization may be regarded as a "buffer" to maintain the stability of the Fe-based components and enhance the reversibility of the electrochemical reaction. This work confirms the practicability of constructing the hierarchical structure bimetallic sulfides with the promising electrochemical performance. [ABSTRACT FROM AUTHOR]

We report here a colorimetric carbon dioxide (CO2) optode sensor with a polypropylene microporous membrane on top of a thin layer (30 μm) of polyurethane hydrogel. The diffusion of CO2 across the polypropylene membrane induced pH changes in the hydrogel containing a lipophilic indicator, a cation exchanger, and a cationic amine. The ratio of the indicator and the cation exchanger was successfully utilized to adjust the sensitivity of the CO2 response. Increasing the relative amount of the cation exchanger made the sensor much more sensitive to CO2 in the lower concentration range. Moreover, the carbarmic formation reaction between the primary amine and CO2 was investigated. The results indicated a very small contribution of carbarmic formation to the overall pH change. With a detection limit of 0.014 % for the CO2 partial pressure, the sensor was successful applied to monitor CO2 evolution during yeast catalyzed flour fermentation. [ABSTRACT FROM AUTHOR]

In this work, the aluminosilicate glass was subjected to ion-exchange using the KNO 3 -AgCl mixed molten salt in order to strengthen the glass while imparting antimicrobial properties. The concentration distribution of K+ ions and Ag+ ions of the ion-exchanged glasses was characterized by EDS, the effects of ion-exchange temperature (460-500 °C), ion-exchange time (0.5-3 h) and AgCl concentration (0–2.5 wt%) in the mixed molten salt on the strengthening effect and properties of the glass were investigated. The results showed that Ag+-Na+ ion-exchange, K+-Na+ ion-exchange existed simultaneously, and Ag+-Na+ ion-exchange occurred preferentially. Due to the presence of metallic silver, the appearance of the Ag+ ion-exchanged glass was light yellow and its transmittance showed a decrease. The surface compressive stress trended up and then down with increasing temperature and time because of the stress relaxation effect. The Vickers hardness of ion-exchanged glass increased by 15%, and the densities and chemical stability were also increased. Ions leaching experiments showed that the Ag+ ions release concentration of silver-loaded glass in aqueous environment can reach the bactericidal level. It has been shown that ion-exchange of glass in KNO 3 -AgCl mixed molten salts allowed the glass to be strengthened and incorporated with antimicrobial active ions, its chemical stability was improved, too. [ABSTRACT FROM AUTHOR]

To clarify the Ni species of NiO/SiO2-Al2O3 catalysts that are active for ethylene oligomerization, 18 types of NiO/SiO2-Al2O3 were prepared using three Ni-loading methods (i.e., ion-exchange, impregnation, and homogeneous precipitation), with different Ni-loadings (1–20 wt%), and examined with respect to their structure and catalytic activity for ethylene oligomerization. Characterized by N2 adsorption, powder XRD, FE-SEM, H2-TPR, NH3-TPD, and C2H4-TPD showed that Ni species in the catalysts prepared by ion-exchange were mainly ion-exchanged Ni cations. In contrast, Ni species in the catalysts prepared by impregnation were a mixture of ion-exchanged Ni cations and NiO particles, and those in the catalysts prepared by homogeneous precipitation were all NiSiO3 particles. Catalytic-reaction tests at 300 °C and 0.1 MPa revealed the following: the ion-exchanged Ni cations showed the highest C2H4 conversion rate; the NiSiO3 particles showed a moderate reaction rate; and the NiO particles were not active for ethylene oligomerization. We concluded that the high catalytic activity of the ion-exchanged Ni cations was a result of their high dispersion and medium-strength acidity, which together promoted the adsorption and activation of ethylene on, and the desorption of oligomerization products from, the catalyst. [ABSTRACT FROM AUTHOR]

Sucrose crystallization process is greatly inhibited by high Na+, K+ and Ca2+ content in the crystallizing medium—sugar juice. In this study, unmodified pressed sugar beet pulp was used as a weak polyfunctional cation exchanger for the removal of Na+, K+ and Ca2+ from an alkalized sugar juice in a closed-loop column system. Cation removal effect was evaluated through the influence of temperature (30–70 °C), pH (8.5–12.5) and volume (150–300 ml) of alkalized juice. Sugar beet pulp exhibited the highest Ca2+ removal (56.58%) at 70 °C and pH value of 12.5, indicating strong impact of cation solubility, precipitation and valence. Milder conditions of alkalized sugar juice such as temperature (50 °C) and pH value (10.5) contributed to the maximum removal of Na+ (15.07%) and K+ (10.58%). Component analysis of the heteroporous sugar beet pulp with total porosity of 53% and specific surface area of 0.9 m2/g indicated hydroxyl and carboxyl groups as the main centers for an ion-exchange process in the material used, which was confirmed by FTIR analysis. This is the first time that unmodified pressed sugar beet pulp (PSBP) has been used as biosorbent for Na+, K+ and Ca2+ removal in a closed-loop column system. [ABSTRACT FROM AUTHOR]

The interactions between counterions and electronic carriers in electrically doped semiconducting polymers are important for delocalization of charge carriers, electronic conductivity, and thermal stability. The introduction of a dianions in semiconducting polymers leads to double doping where there is one counterion for two charge carriers. Double doping minimizes structural distortions, but changes the electrostatic interactions between the carriers and counterions. Polymeric ionic liquids (PIL) with croconate dianions are helpful to investigate the role of the counterion in p‐type semiconducting polymers. PILs prevent diffusion of the cation into the semiconducting polymers during ion exchange. The redox‐active croconate dianions undergo ion exchange with doped semiconducting polymers depending on their ionization energy. Croconate dianions are found to reduce doped films of poly(3‐hexyl thiophene), but undergo ion exchange with a polythiophene with tetraethylene glycol side chains, P(g42T‐T), that has a lower ionization energy. The croconate dianion maintains crystalline order in P(g42T‐T) and leads to a lower activation energy for the electrical conductivity than PF6− counterions. The control of the doping level with croconate allows optimization of the thermoelectric performance of the semiconducting polymer. The thermal stability of the doped films of P(g42T‐T) is found to depend strongly on the nature of the counterion. [ABSTRACT FROM AUTHOR]

As a result of the high theoretical capacities, transition metal sulfides have attracted increasing attention as potential anodes for sodium-ion batteries (SIBs), but severely suffer from large volumetric variations, sluggish kinetics, and polysulfide shuttling. Herein, utilizing metal–organic frameworks (MOFs) as functional templates, heterostructured CoS2/FeS nanoparticles confined in a hollow N-doped carbon framework are successfully fabricated via a controlled ion-exchange reaction combined with subsequent carbonization and sulfurization processes. The construction of CoS2/FeS heterointerfaces promotes electron transfer and provides more active sites, while the derived N-doped carbon framework with a unique hollow interior effectively improves the electrical conductivity, alleviates the volumetric variations, and facilitates the sodium storage process with shortened Na+ diffusion paths. As anodes for SIBs, the optimal CoS2/FeS hybrid composite exhibits a high initial Coulombic efficiency (ICE) of 89.3%, a prolonged cycle life with a capacity of 494 mAh g–1 over 500 cycles under a current density of 1.0 A g–1, and an excellent rate capability of 428 mAh g–1 at 5.0 A g–1, showing the great promise for SIBs. This research offers an efficient and feasible approach for exploring and fabricating bimetallic sulfide heterostructures with a unique hollow structure for high-performance metal-ion batteries. [ABSTRACT FROM AUTHOR]

Ionic conductivity in silicate glasses is a major issue in the energy sector due to its detrimental effect on electric energy generation and storage and has received increasing attention over the past years. In this study, surface modification of soda–lime–silica (SLS) float glass via acid‐leaching treatment (pH 1) was implemented to understand the impact on ionic transport. The acid‐leaching treatment created a sodium‐depleted "silica‐like" structure in the near‐surface region with depths of 110 ± 20 nm for the air‐side and 93 ± 2 nm for the tin‐side of the SLS glass. Using the thermally stimulated depolarization current technique, two thermally activated relaxation peaks were found to be associated with different ion migration mechanisms. The first peak (P1) with activation energy of ∼0.85 eV was attributed to dc conduction of Na+ ions through the glass bulk. A second overlapping peak (P2) at a higher temperature was found to be related to a more limited Na+ ion migration through the acid‐leached structure, due to H+ conduction, or a coupled contribution of both mechanisms. [ABSTRACT FROM AUTHOR]

Borosilicate glass has been extensively studied due to its unique properties of solidifying high‐level radioactive waste (HLW). However, the responses of borosilicate glass under γ irradiation are not fully understood. In this work, NBS9 and NBS10 glass were irradiated by γ‐rays at absorbed doses of 8 kGy and 800 kGy, respectively. Scanning electronic microscopy, energy dispersive X‐ray, and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) were used to observe the surface morphology and elemental distributions. The results show that the borosilicate glass remains stable until the absorbed dose was up to 800 kGy. At 800 kGy, the samples precipitate particles composed of Na and O on the surface. Na and B near the surface are significantly reduced under γ‐rays irradiation. The results indicate that the effects of γ irradiation on glass vitrification are obvious with certain accumulated doses. The changes of glass structures and elemental distributions by γ‐ray irradiation are also dependent on glass compositions. [ABSTRACT FROM AUTHOR]

Complexes of Co(II) and Ni(II) with 2,6-pyridine dicarboxylic acid (PydcH2) have been synthesized in the NaX (zeolite-X) nanopores. The formation of zeolite X encapsulated Co(II) and Ni(II) complexes ([M(pydcH)2]-NaX, [M = Co(II) and Ni(II])] were confirmed using spectroscopic methods of FT-IR, elemental analysis, XRD, FE-SEM, and TEM. It was affirmed that the encapsulation of complexes in NaX pores was formed without changes in the structure and shape of the zeolite. The oxidative degradation reaction of atenolol with hydrogen peroxide as an oxidant was performed in the presence of synthesized [M(pydcH)2]-NaX nanocomposites to study their catalytic activity. Therefore, oxidation of atenolol was performed under different conditions of catalyst, temperature, and time. Under optimal conditions, catalysts [Co(pydcH)2]-NaX and [Ni(pydcH)2]-NaX showed 82.3% and 71.1% activity of atenolol oxidation, respectively. These catalysts were stable after recovery and were used three more times. The results showed that these catalysts were reusable and had a reduction in the catalytic activity of less than ten percent. [ABSTRACT FROM AUTHOR]

Ion-exchange has been widely employed to modify the composition and structure of glasses. In this work, Cs–K ion-exchange was carried out to facilitate the precipitation of cesium lead halide perovskite nanocrystals in the surface layer of glasses. Both Cs 4 PbBr 6 and CsPbBr 3 perovskite nanocrystals and KBr nanocrystals can be precipitated through ion-exchange in nitrate salt. Content of Cs 4 PbBr 6 and CsPbBr 3 perovskite nanocrystals is strongly dependent on the composition of nitrate salt, ion-exchange conditions, and post-thermal annealing. High concentration of Cs in nitrate salt, long ion-exchange duration, and post-thermal annealing are effective to promote the formation of CsPbBr 3 perovskite nanocrystals. Results reported is valuable for the developing of cesium lead halide perovskite nanocrystals embedded glass for light converters. [ABSTRACT FROM AUTHOR]

In an attempt to widen the family of Phosphorus Metal Halides (MxPyXz) and enable new applications, post-synthetic modifications to the MxPyXz, Cu2P3I2 have been reported. While such a technique suggests access to an entirely new family of MxPyXz-based materials, we report, in this work, that the ion-exchange process seemingly influences important properties such as the crystallographic pattern and vibrational modes.

Arsenic (As), a poisonous and carcinogenic heavy metal, affects human health and the environment. Numerous technologies can remove As from drinking water. Adsorption is the most appealing option for decentralized water treatment systems (DWTS) for small communities and household applications because it is reliable, affordable, and environmentally acceptable. Sustainable low-cost adsorbents make adsorption more appealing for DWTS to address some of the small communities’ water-related issues. This review contains in-depth information on the classification and toxicity of As species and different treatment options, including ion exchange, membrane technologies, coagulation-flocculation, oxidation, and adsorption, and their effectiveness under various process parameters. Specifically, different kinetic and isotherm models were compared for As adsorption. The characterization techniques that determine various adsorbents’ chemical and physical characteristics were investigated. This review discusses the parameters that impact adsorption, such as solution pH, temperature, initial As concentration, adsorbent dosage, and contact time. Finally, low-cost adsorbents application for the removal of As was discussed. Adsorption was found to be a suitable, cost-effective, and reliable technology for DWTS for small and isolated communities. New locally developed and low-cost adsorbents are promising and could support sustainable adsorption applications.

Geothermal power plants produce large amounts of high-temperature fluids from variable depths. These fluids can be enriched in lithium to up to 240 mg/L, rendering them an exploitable resource, not yet processed at industrial scale. The pressure on Li demand is expected to increase in the future, making the technical degradability of new Li resources indispensable. We examine Li-extraction methods from aqueous solutions systematically, dealing with evaporation, direct precipitation, membrane-related processes, solvent extraction, sorption, and ion exchange. Sorption and ion-exchange techniques are regarded to be the most promising methods with a high potential for the feasible lithium extraction. Therefore, Li sorption on different inorganic sorbents, in particular for the implementation into operating geothermal power plants, is evaluated. Inorganic sorbents, such as lithium–manganese oxide, titanium oxide, aluminum hydroxide, iron phosphate, clay minerals, and zeolite group minerals besides other sorbents, e.g. zirconium phosphate, tin antimonate, antimony oxide, tantalum oxide, and niobium oxide, are regarded. Promising inorganic sorbents for an environmentally friendly, efficient, and selective Li extraction are lithium–manganese oxide, iron phosphate, or zeolite. To evaluate the effectiveness of these sorbents to large-scale industrial Li2CO3 (or LiOH) production, we highlight their potential advantages and disadvantages in the application under geothermal operating conditions. [ABSTRACT FROM AUTHOR]

This study investigates silver ion-exchange of the transparent lithium-mica glass-ceramic in a molten mixture of AgNO 3 and Ag 2 SO 4 to realize the glass-ceramic antibacterial activity and improved mechanical properties. The ion-exchanged glass-ceramic was heated at 700 °C. Li+ ions in the interlayers of mica near surface of the glass-ceramic were exchanged for Ag+ ions in the molten salt. Ag+ ions intruded deeper inside from surface as the soaking time of the ion-exchange increased, disturbing the layer structure of the mica. Heating also diffused Ag+ ions deeper inside the glass-ceramic, reducing the concentration of Ag+ ions near the surface and realizing a uniform distribution of Ag+ ions to create a regular layer structure of mica. Both the ion-exchanger and the heated ion-exchanger showed antibacterial activity against Escherichia coli. However, their activities decreased in repeated antimicrobial tests. Because ion-exchange generated compressive stress near the surface, the Vickers hardness and fracture toughness increased, whereas heating lowered the heightened hardness. Although ion-exchange and subsequent heat treatment improved the machinability of the glass-ceramic, ion-exchange alone did not. [ABSTRACT FROM AUTHOR]

Flue-gas desulphurization (FGDs) systems were developed primarily to remove sulphur dioxide (SO2) from industrial gas streams. The main techniques adopted involve wet scrubbing, particularly lime/limestone scrubbing. These techniques are relatively simple, cost less, and have thus, become applicable to other types of plants that emit SO2 such as refineries and smelters. In lime and limestone scrubbing, calcium compounds are added as slurry to the scrubber liquid, and this can result in the formation of solid calcium salts. As a result, the efficiency of such wet calcium-containing scrubbing systems is limited by the solubility of calcium salts in the slurry. As the concentrations of calcium ions build up in the water, the solubility limit of calcium sulphate (CaSO4) and many other compounds is often exceeded. In such systems, the formation of supersaturated CaSO4 causes scaling or deposition in the scrubber. The scaling problem further results in numerous plant downtimes due to the need to open lines and descale. The current review looks into existing and potential methods that have and can be developed to prevent or remove the formation of scaling in FGD systems such as scrubbers. A particular focus of this review is given to approaches such as chemical "softening" of hard waters using ion-exchange and precipitation using lime and soda ash. This review also looks into a contentious physical water treatment – magnetic water treatment (MWT) - as a potential alternative and environmentally conscious solution for the prevention of scale in scrubbers and hard waters in general. [ABSTRACT FROM AUTHOR]

The radionuclides of cesium (Cs) and strontium (Sr) are dangerous products of nuclear fission that can be accidentally released into wastewater. In the present work, the capacity of thermally treated natural zeolite (NZ) from Macicasu (Romania) to remove Cs+ and Sr2+ ions from aqueous solutions in batch mode was investigated by contacting different zeolite quantities (0.5, 1, and 2 g) of 0.5–1.25 mm (NZ1) and 0.1–0.5 mm (NZ2) particle size fractions with 50 mL working solutions of Cs+ and Sr2+ (10, 50, and 100 mg L−1 initial concentrations) for 180 min. The concentration of Cs in the aqueous solutions was determined by inductively coupled plasma mass spectrometry (ICP-MS), whereas the Sr concentration was determined by inductively coupled plasma optical emission spectrometry (ICP-OES). The removal efficiency of Cs+ varied between 62.8 and 99.3%, whereas Sr2+ ranged between 51.3 and 94.5%, depending on the initial concentrations, the contact time, the amount, and particle size of the adsorbent material. The sorption of Cs+ and Sr2+ was analyzed using the nonlinear form of Langmuir and Freundlich isotherm models and pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The results indicated that the sorption kinetics of Cs+ and Sr2+ on thermally treated natural zeolite was described by the PSO kinetic model. Chemisorption dominates the retention of both Cs+ and Sr2+ by strong coordinate bonds with an aluminosilicate zeolite skeleton. [ABSTRACT FROM AUTHOR]

Banana peels (BP) are the outer covering of a banana fruit and are usually discarded as abundant and underutilized waste from banana production and consumption. This work investigated the bioresource for one-pot preparation of carboxyl cellulose nanofibers (CCNF) using the nitro-oxidation method. Briefly, BP was added to a mixture of HNO3 and NaNO2 at 30–50oC for 6 h. To characterize the obtained material, different methods, including X-ray diffraction, TEM images, FTIR spectroscopy, EDX spectroscopy, and acid-base titration, were used. TEM images reveal that the nanofibers were mainly formed with a diameter of roughly 20–50 nm. Moreover, the results of FTIR, EDX, and titration proved the formation of carboxylic acid (-COOH) groups in CCNF with an amount of 4.9 mmol/g, or 22 wt%. This high carboxyl content makes CCNF an ionexchange material, thereby enabling the development of new applications. Compared with traditional multistep processes for the preparation of cellulose nanomaterials, the current approach is simpler, uses fewer chemicals, and consumes less energy. Overall, these successful results not only valorize potential banana peel waste but also introduce an advanced material for further use. [ABSTRACT FROM AUTHOR]

Conformal deposition of wide-bandgap perovskite films along pyramidal silicon surfaces through the dry process is essential for fabricating large-area textured silicon/perovskite tandem solar cells. However, it is difficult to control the composition of mixed perovskite films through dry processes because the deposition rate in organic and inorganic components is different when depositing perovskite films using a multi-source or premixed-source. In this study, MAPbI3 perovskite films were deposited through radio-frequency magnetron sputtering and dry conversion processes, and wide-bandgap perovskite films with mixed halide compositions were prepared by immersion in a MABr/IPA solution. Based on the results, the bandgap of the perovskite films increased with the immersion time. In addition, a uniform depth profile of the perovskite composition was observed in the film. Perovskite solar cells were manufactured to verify their electrical characteristics. Finally, wide-bandgap perovskite films were conformally deposited on textured silicon surfaces. These results show the great potential of applications in silicon/perovskite tandem solar cells. [ABSTRACT FROM AUTHOR]