Exchange Of Na Research Articles

Hydrochar Utilization for Saline‐Alkali Soil Amelioration and Its Carbon Sequestration Potential Assessment

AbstractFor the current situation of saline‐alkali soil amelioration, it is urgent to explore a multi‐objective amelioration strategy involving crop income increase and environmental benefits. This study used pine‐needle hydrochar to ameliorate saline‐alkali soil and conducted column and pot experiments to investigate its effects on soil properties and crop growth. And the environmental advantages of hydrochar are evaluated through Life Cycle Assessment (LCA). The electrical conductivity, exchangeable sodium percentage, and pH of saline‐alkali soil ameliorated with hydrochar using the column elution method are reduced by 60%, 58%, and 1.2 pH units, respectively, compared to the original soil. Also, the gene copy number of the ameliorated soil has doubled according to qPCR determination. Pot experiment results show that the root length, fresh weight, and germination rate of wheatgrass are increased by 107, 75, and 20%, respectively. These results demonstrated that the exchange of Na+ with H+ released from hydrochar reduced the soil alkalinity and the viability of organisms is enhanced. Moreover, based on this study's data including the hydrochar dosage and wheatgrass yield, the LCA results showed 3.7 × 109 t CO2e carbon sequestration potential and significant environmental benefits.

Probing Metal Ion Adduction in the ESI Charged Residue Mechanism via Gas-Phase Ion/Ion Chemistry.

The final stages of the charged residue mechanism/model (CRM) for ion generation via electrospray ionization (ESI) involves the binding of excess charge onto analyte species. Ions of both polarities can bind to the analyte with an excess of ions of the same polarity as the droplet. For large biomolecule/biocomplex ions, which are commonly the species of interest in native mass spectrometry (MS), the binding of acids and salts onto the analyte can lead to extensive broadening of ion signals due to adduction. Therefore, heating step(s) to facilitate desolvation and salt adduct removal are commonplace. In this work, we describe an approach to study the final stages of CRM using gas-phase ion/ion reactions to generate analyte ion/salt clusters of well-defined composition, followed by gas-phase collision-induced dissociation (CID). While there are many variables that can be studied systematically via this approach, the work described herein is focused on salt clusters of the form [Na10X11]-, where X = acetate (Ac-), chloride (Cl-), or nitrate (NO3-), in reaction with a common charge state of ubiquitin as well as several model peptides. Experiments in which equimolar quantities of each salt (i.e., NaAc, NaCl, and NaNO3) are subjected to ESI with ubiquitin (Ubi) and gas-phase ion/ion reaction studies involving [Na10X11]- and [Ubi + 6H]6+ show similar trends, in terms of the extent of sodium ion incorporation into the protein ions. Ion/ion reaction studies using model peptides show that the acetate-containing salt transfers significantly more Na+ ions into the peptide ions. Exchange of Na+ for H+ is shown to occur at the C-terminus and at up to all of the amide linkages using [Na10X11]-, whereas only the C-terminus engages in Na+/H+ exchange with [Na10Cl11]- and [Na10(NO3)11]-. In the latter cases, an additional Na+ is taken up as the excess positive charge, presumably due to solvation of the charge by multiple sites (e.g., carbonyl oxygens and basic sites).

Boric acid recovery from wastewater by chromatographic separation and mathematical modeling

The new approaches in industrial wastewater management underscores the importance of reclaiming valuable materials. Within the boron industry, the generation of substantial wastewater containing preliminary boron species is a significant concern. This study focuses on recovering boric acid from boron production wastewater, addressing the challenge of separating impurities like sulfate, calcium, and magnesium. The methodology adopts chromatographic separation using a cation exchange resin in two forms: (1) Finex CS10GC cation exchanger in Na+ form and (2) Finex CS10GC cation exchanger in Ca2+/Mg2+ form. Notably, the Finex CS10GC ion exchanger in Na+ form achieves a separation efficiency of 95.5 % at a flow rate of 5 mL/min with a 0.20 bed volume (BV) loading. In contrast, the Ca2+/Mg2+ loaded resin achieves a separation efficiency of 23.3 % at the same flow rate. As the boron loading rate decreases to 10 %, the separation efficiency increases to 42.6 %. The flow rate also plays a crucial role, as an increase corresponds to a decrease in separation efficiency. Notably, the Finex CS10GC ion exchanger in Na+ form consistently exhibits superior separation efficiency and band resolution. A mathematical model is introduced to simulate the effective separation of boric acid from other impurities. The quality of the recovered boric acid conforms to the standard grade (Merck KGaA), exhibiting a purity level within the range of 99.5–100 %, suggesting substantial economic value. The proposed recovery process contributes significantly to environmental preservation by mitigating waste discharge, exemplifying a noteworthy commitment to resource conservation.

Research new type of cation-exchange resin for waste water treatment

This article presents the studies obtaining and research new polycondensation type phosphoric cation-exchange resin. The conditions for the phosphorylation of this polymer were selected from the experiments accumulated in relation to the phosphorylation reactions of low- and high-molecular compounds. The resulting polymer had an exchange capacity for a 0.1 N NaOH solution – 5,5-5,6 mEq/g and contained 16,5% phosphorus. Based on the studies carried out, the optimal conditions for the synthesis of the styrene-furfural polymer are assumed to be: the reaction temperature is 90°C, the concentration of the ZnCl2 catalyst is 0.07 mol per mole of furfural, and the molar ratio of styrene to furfural is 1:1. There was studied an interaction of the cation exchanger in Na- and H-forms with solutions of salts of copper sulfate, nickel, cobalt, sodium chloride, calcium and uranyl nitrate. In order to elucidate the mechanism of sorption of the cations of these metals, were taken the IR-spectra of the cation exchanger in the H- and Na- form, saturated with copper ions. The less dissociated phosphoric acid groups, the stronger hydrogen bond forms phosphoryl oxygen with OH-groups. Therefore, it can be expected that as the cation exchanger is saturated with sodium, the maximum of the band corresponding to the phosphorus-oxygen bond vibrations will slightly shift to longer wavelengths as a result of the destruction of the weaker hydrogen bond.

Effect of pore water on the depressurization of gas hydrate in clayey silt sediments

Marine gas hydrate always occurs in clayey silt sediments partially or fully saturated with water. Pore water is involved in gas hydrate formation and decomposition, which plays an important role in gas recovery from hydrate during depressurization. In this work, the depressurization of methane hydrate in the clayey silt sediments was experimentally investigated in a one-dimensional reactor. The variation of gas production and pressure gradient under the gas-rich and water-rich condition were studied. It was found that the gas production in water-rich environment was much lower than that in gas-rich environment as the movement of hydrate dissociating front is slower in water-rich environment. The permeability of the clayey silt sediments was measured before hydrate formation and after hydrate decomposition, which indicated that there was a large depression in the permeability of the clayey silt sediments after hydrate decomposition, which could be attributed to the hydration swelling of clay minerals with the expansion of diffuse double layer caused by the release of water with lower salinity from gas hydrate dissociation. And the permeability depression of the clayey silt sediments caused by hydrate decomposition was more obvious in water-rich environment, reaching up to ∼50%, and increased with the content of clay minerals. In addition, inorganic salt-based clay stabilizer solution was pre-injected into the clayey silt gas hydrate-bearing sediments before depressurization to mitigate the formation damage during gas hydrate production. The results showed the permeability of the sediments pre-saturated with NH4Cl was maintained at ∼75% of the initial values after gas hydrate decomposition as the exchange of Na+ with NH4+ in sediments was proved to decrease the bound water in montmorillonite interlayers by NMR analysis and inhibit the hydration swelling of clay particles.

Characteristics of fluoride migration and enrichment in groundwater under the influence of natural background and anthropogenic activities

Excessive enrichment of fluoride threatens ecological stability and human health. The high-fluoride groundwater in the Chagan Lake area has existed for a long time. With the land consolidation and irrigation area construction, the distribution and migration process of fluoride have changed. It is urgent to explore the evolution of fluoride under the dual effects of nature and human. Based on 107 groundwater samples collected in different land use periods, hydrogeochemistry and isotope methods were combined to explore the evolution characteristics and hydrogeochemical processes of fluoride in typical high-fluoride background area and elucidate the impact of anthropogenic activities on fluoride migration. The results indicate that large areas of paddy fields are developed from saline-alkali land, and its area has increased by nearly 30%. The proportion of high-fluoride groundwater (>2 mg/L) has increased by nearly 10%, mainly distributed in the new irrigation area. Hydrogeochemical processes such as dissolution of fluorine-containing minerals, precipitation of carbonate minerals and exchange of Na+, Ca2+ on the water-soil interface control the enrichment of fluoride. The groundwater d-excess has no obvious change with the increase of TDS, and human activities are one of the reasons for the increase of fluoride. The concentration of fluoride is diluted due to years of diversion irrigation in old irrigation area, whereas the enrichment of δ2H, δ18O and Cl− in new irrigation area indicates that the vertical infiltration of washing alkali and irrigation water brought fluoride and other salts to groundwater. Fertilizer and wastewater discharges also contribute to the accumulation of fluoride, manifesting as co-increasing nitrate and chloride salts. The results of this study provide a new insight into fluoride migration under anthropogenic disturbance in high-fluoride background areas.

Effect of alkali amount on layered titanate as tunable solar reflective material

In urban areas huge population play a pivotal role on environmental pollution, the roofs of buildings in these areas have a greater effect on the absorption of heat from the sun light which increases the greenhouse gases emission to the environment and finally causes global warming. To avoid such energy consumption, special coating materials are important to block radiations in the near-infrared, (NIR) spectrum. In the current work, an experimental study for the evaluation of this phenomenon about infrared-reflective materials has been made. A layered type Na2Ti3O7 (NTO) as a parent compound was used to produce Na2-xHx Ti3O7 type titanate (HTO) material by the exchange of Na+ for H+. Here x means the ion-exchanged Na+ for H+ in the titanate (Ti3O7)2- gallery. Depending on the Na+ amount in the titanate gallery, the NTO and the ion exchanged HTO materials showed the high and tunable solar reflective properties from 84 to 94% compared to high refractive index commercial rutile TiO2. The materials crystalline nature, structural, morphological and optical properties were investigated using XRD, FE-SEM, EDS and UV–Vis–NIR spectrophotometer. The results showed that the layered NTO and ion-exchanged HTO materials could be a suitable candidate for tuning solar heat reflectance in coating industries.

Elevated microglial oxidative phosphorylation and phagocytosis stimulate post-stroke brain remodeling and cognitive function recovery in mice

New research shows that disease-associated microglia in neurodegenerative brains present features of elevated phagocytosis, lysosomal functions, and lipid metabolism, which benefit brain repair. The underlying mechanisms remain poorly understood. Intracellular pH (pHi) is important for regulating aerobic glycolysis in microglia, where Na/H exchanger (NHE1) is a key pH regulator by extruding H+ in exchange of Na+ influx. We report here that post-stroke Cx3cr1-CreER+/−;Nhe1flox/flox (Nhe1 cKO) brains displayed stimulation of microglial transcriptomes of rate-limiting enzyme genes for glycolysis, tricarboxylic acid cycle, and oxidative phosphorylation. The other upregulated genes included genes for phagocytosis and LXR/RXR pathway activation as well as the disease-associated microglia hallmark genes (Apoe, Trem2, Spp1). The cKO microglia exhibited increased oxidative phosphorylation capacity, and higher phagocytic activity, which likely played a role in enhanced synaptic stripping and remodeling, oligodendrogenesis, and remyelination. This study reveals that genetic blockade of microglial NHE1 stimulated oxidative phosphorylation immunometabolism, and boosted phagocytosis function which is associated with tissue remodeling and post-stroke cognitive function recovery.

Synthesis of Cu-TiNT, characterization, and antibacterial properties evaluation

Copper ion–exchanged titanate nanotubes (Cu-TiNTs) had been prepared from a simple ion-exchange reaction between copper salt and sodium titanate nanotubes (Na-TiNT) which was synthesized by alkaline hydrothermal synthesis starting from titanium oxide of anatase phase. A thorough structural and morphological characterization of Cu-TiNT (and Na-TiNT) was done by using various material characterization techniques, such as X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy to reveal retention of tubular structure of titanate nanotubes with decoration of copper (II) oxide on the surface of the tubes as well as an exchange of Na+ ion by Cu2+ ion in the interlamellar space. The antibacterial properties of the Cu-TiNT were evaluated by broth macrodilution method using microtiter trays, with concentration ranging between 512 and 0.5 μg/mL. The Cu-TiNT demonstrated no clinically relevant antibacterial activity alone (minimum inhibitory concentration ≥ 1024 μg/mL), but when associated with gentamicin, this compound enhanced the antibiotic activity of this drugs against strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. The results were very promising to the utilization of the Cu-TiNT as an adjuvant to the antibiotic therapy.

Crystal chemistry of ivanyukite-group minerals, A3–xH1+x[Ti4O4(SiO4)3](H2O)n (A = Na, K, Cu), (n = 6–9, x = 0–2): crystal structures, ion-exchange, chemical evolution

AbstractMicroporous slicates with the pharmacosiderite structure and the general formula A3–xH1+x[Ti4O4(SiO4)3](H2O)n (A = Na, K, Cu), (n = 6–9, x = 0–2) are outstanding in their ion-exchange properties. The ivanyukite mineral group consists of three species, one of which has two polymorphs. The minerals forming a progressive series: ivanyukite-Na-T → ivanyukite-Na-C → ivanyukite-K → Cu-rich ivanyukite-K → ivanyukite-Cu, have been studied by single-crystal X-ray diffraction, electron microprobe analysis and Raman spectroscopy. The microporous heteropolyhedral framework of the ivanyukite-group minerals is based on cubane-like [Ti4O4]8+ clusters that share common corners with SiO4 tetrahedra to form wide three-dimensional channels suitable for the migration of Na+, K+ and Cu2+ ions. Ivanyukite-Na-T that has a R3m symmetry loses Na+ in aqueous solutions via the substitution Na+ + O2‒ ↔ □ + OH‒, which allows for the migration of K+ ions and transformation of initial structure into the cubic (P$\bar{4}3m$) ivanyukite-Na-C polymorph or into ivanyukite-K, when most of Na is lost. Natural ivanyukite-Na-C is shown to contain domains of both R3m (subordinate) and P$\bar{4}3m$ (dominant) symmetry with the chemical composition determining the stability and dominance of cubic or trigonal forms. Incorporation of Cu into the crystal structure ivanyukite-K via the substitution K+ + OH− ↔ Cu2+ + O2− in aqueous solutions results in the formation of ivanyukite-Cu. Post-crystallisation processes (such as exchange of Na+, K+, Cu2+, and/or hydration/dehydration of primary phases) are widespread in hyperagpaitic rocks of the Kola alkaline massif and the respective mineral transformations contribute to the diversity of mineral species.

Influence of solid electrolyte upon the repeatability and reproducibility of all-solid-state ion-selective electrodes with inorganic insertion material paste

The effects of the solid electrolyte β”-alumina upon the electrode responses of all-solid-state ion-selective electrodes (ISEs) with the inorganic insertion material Na0.33MnO2 were examined for Na+-ISE and K+-ISE. β”-alumina was added into the Na0.33MnO2 paste as a Na+-supply source for the ion-to-electron transducer Na0.33MnO2. For K+-ISE in the absence of β”-alumina, the insertion ion from Na0.33MnO2, Na+, was not identical to the target ion, K+, in the K+-selective membrane; thus, the exchange of Na+ for K+ at the Na0.33MnO2 | selective-membrane interface caused significant potential drift of K+-ISE; however, this drift was suppressed by the addition of β”-alumina into the Na0.33MnO2 paste. The obtained potential repeatability and Eo reproducibility (± 1.0 mV) for K+-ISE were made similar to those for Na+-ISE with Na0.33MnO2; these results show that all-solid-state ISEs can be developed for various ions without changing the inorganic insertion material.

Energetic Characterization of Faujasite Zeolites Using a Sensor Gas Calorimeter

In addition to the adsorption mechanism, the heat released during exothermic adsorption influences the chemical reactions that follow during heterogeneous catalysis. Both steps depend on the structure and surface chemistry of the catalyst. An example of a typical catalyst is the faujasite zeolite. For faujasite zeolites, the influence of the Si/Al ratio and the number of Na+ and Ca2+ cations on the heat of adsorption was therefore investigated in a systematic study. A comparison between a NaX (Sodium type X faujasite) and a NaY (Sodium type Y faujasite) zeolite reveals that a higher Si/Al ratio and therefore a smaller number of the cations in faujasite zeolites leads to lower loadings and heats. The exchange of Na+ cations for Ca2+ cations also has an influence on the adsorption process. Loadings and heats first decrease slightly at a low degree of exchange and increase significantly with higher calcium contents. If stronger interactions are required for heterogeneous catalysis, then the CaNaX zeolites must have a degree of exchange above 53%. The energetic contributions show that the highest-quality adsorption sites III and III’ make a contribution to the load-dependent heat of adsorption, which is about 1.4 times (site III) and about 1.8 times (site III’) larger than that of adsorption site II.

Effects of pH and Ca exchange on the structure and redox state of synthetic Na-birnessite

Abstract Birnessite-like minerals are among the most common Mn oxides in surficial soils and sediments, and they mediate important environmental processes (e.g., biogeochemical cycles, heavy metal confinement) and have novel technological applications (e.g., water oxidation catalysis). Ca is the dominant interlayer cation in both biotic and abiotic birnessites, especially when they form in association with carbonates. The current study investigated the structures of a series of synthetic Ca-birnessite analogs prepared by cation-exchange with synthetic Na-birnessite at pH values from 2 to 7.5. The resulting Ca-exchanged birnessite phases were characterized using powder X-ray diffraction and Rietveld refinement, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning and transmission electron microscopy. All samples synthesized at pH values greater than 3 exhibited a similar triclinic structure with nearly identical unit-cell parameters. The samples exchanged at pH 2 and 3 yielded hexagonal structures, or mixtures of hexagonal and triclinic phases. Rietveld structure refinement and X-ray photoelectron spectroscopy showed that exchange of Na by Ca triggered reduction of some Mn3+, generating interlayer Mn2+ and vacancies in the octahedral layers. The triclinic and hexagonal Ca-birnessite structures described in this study were distinct from Na- and H-birnessite, respectively. Therefore, modeling X-ray absorption spectra of natural Ca-rich birnessites through mixing of Na- and H-birnessite end-members will not yield an accurate representation of the true structure.

HYDROCHEMICAL FACIES DESCRIPTION TO ASSESS THE WATER QUALITY OF HABBANIYA LAKE, IRAQ

The present study depicts the hydrochemical processes controlling the variance in the hydrochemical facies for sixteen samples obtained from Habbaniya Lake. The water samples were analyzed for the major ions (cations and anions) data in mg/l, total dissolved solids in mg/l, pH unitless, electrical conductivity in μS/cm, and temperature in °C. Piper trilinear (three-line) diagram indicates the overall of samples belongs to class 1 (Ca2+, Mg2+, Cl-, SO42-), category I (SO42- - Cl- and Ca2+ - Mg2+), and permanent total hardness (calcium chloride type). The contribution of cations in the Habbaniya lake was almost the same percentage (no dominant cation), while the SO42- is the dominant ion of the surface water in the Habbaniya lake. The analytical values showed that overall the samples were freshwater and low enrichment salts within the permissible limits of the World Health Organization standards. Irrigation parameters and water quality index were calculated for samples to assess water for agricultural and drinking uses for the inhabitants of the study area. The basic exchange is the exchange of Na+ and K+ ions in water with Mg2+ and Ca2+ ions in materials which is exposed to weathering.

Thermal Shock Behavior of a Soda Lime Glass Treated by Ion Exchange

In this work, we have submitted a soda lime glass to thermochemical treatment by ion exchange in order to introduce compressive stresses in their surface. Subsequently, we studied the hot-cold thermal shock resistance of ion-exchange reinforced glass. A potassium ion from the molten salt bath replaces the sodium ion of the glass surface by a superficial diffusion process. We have determined the potassium diffusion profile by two techniques: X-ray fluorescence spectroscopy XRF and X-rays microanalysis coupled with Scattering Electronic Microscopy. In addition, for the same purpose, we used X-ray fluorescence spectroscopy. Then, we determined by micro-indentation the profile of the compressive stresses induced in the glass surface by the exchange of Na+ ions by larger ones of K+. The compressive stress profile induced by chemical tempering depends on potassium ion concentration. It reaches a maximum value of 988 MPa for a treatment done during 50 hours at 480°C. We have subjected the glass specimens treated by ion exchange to a hot-cold thermal shock technique; we realized the cooling by air jet at room temperature. The heat transfer coefficient was about 600 W/m2 °C (Biot number β = 0.3). We have determined the residual strengths of the ion exchange treated and thermal shocked specimens by a three-point bending test. The strength is improved; it passes from 90 MPa of the as received glass to 380 MPa for the chemically treated glass. We noticed that the critical temperature difference ΔTc, which caused the thermal shock fracture, depends on the glass samples states. Consequently, because of the thermochemical treatment, ΔTc has shifted to higher temperatures. Its value was 254°C for raw glass and reached 455°C for the case of reinforced glass by ion exchange at 480°C during 50 hours. The thermochemical ion exchange treatment improve the glass thermal shock resistance.

Ion-exchange properties of the natural zeolite amicite

Crystals of the natural zeolite amicite, ideally K4Na4(Al8Si8O32)·10H2O, were ion-exchanged in the reactions with 0.1 N aqueous solutions of AgNO3, RbNO3, CsNO3 and Pb(NO3)2 at 363 K for 24 h. Under these conditions, Cs+ substitutes K+ whereas the most part of Na+ remains unexchanged; Rb+ partly substitutes both Na+ and K+; Pb2+ and Ag+ completely substitute Na+ and K+. All the compounds are monoclinic. The Cs- and Rb-substituted samples have unit-cell parameters close to those of initial amicite. The exchange of Na+ and K+ for Ag+ is accompanied by a significant decrease of the unit-cell volume. The unit-cell parameter c of Pb-amicite is nearly threefold larger than the c parameter of initial amicite. Infrared spectra show that framework topology is preserved during the ion exchange. The crystal structures of initial and Cs-exchanged amicites have been solved by direct methods.

The influence of Si/Al ratio on sulfate durability of metakaolin-based geopolymer

The durability of geopolymers in sulfate is essential to their application in harsh environments. In this paper, the influence of Si/Al ratio, one of the major composition parameters of metakaolin-based geopolymer (MKG), on its durability in both sodium and magnesium sulfate solutions was investigated in detail. The results indicate there is a strong coupling effect appears between Si/Al ratio and the sulfate type. The ion exchange process of MKG with different Si/Al ratios is significantly influenced by the cation of sulfate. The exchange of OH− and SO42− dominates the ion exchange process in sodium sulfate solution while the exchange of Na+ and Mg2+ dominates in magnesium sulfate solution. In addition, the variation of strength, chemical structure, micromorphology in two sulfate environments is also closely dependent on Si/Al ratio. The Si/Al ratio shows notable influence on micromorphology and strength in magnesium sulfate solution while there is negligible influence of Si/Al ratio in sodium sulfate solution.

New quercetin-coated titanate nanotubes and their radiosensitization effect on human bladder cancer.

Interest in nanostructures such as titanate nanotubes (TNT) has grown notably in recent years due to their biocompatibility and economic viability, making them promising for application in the biomedical field. Quercetin (Qc) has shown great potential as a chemopreventive agent and has been widely studied for the treatment of diseases such as bladder cancer. Motivated by the possibilities of developing a new hybrid nanostructure with potential in biomedical applications, this study aimed to investigate the incorporation of quercetin in sodium (NaTNT) and zinc (ZnTNT) titanate nanotubes, and characterize the nanostructures formed. Qc release testing was also performed and cytotoxicity in Vero and T24 cell lines evaluated by the MTT assay. The effect of TNTs on T24 bladder cancer cell radiosensitivity was also assessed, using cell proliferation and a clonogenic assay. The TNT nanostructures were synthesized and characterized by FESEM, EDS, TEM, FTIR, XRD and TGA. The results showed that the nanostructures have a tubular structure and that the exchange of Na+ ions for Zn2+ and incorporation of quercetin did not alter this morphology. In addition, interaction between Zn and Qc increased the thermal stability of the nanostructures. The release test showed that maximum Qc delivery occurred after 24h and the presence of Zn controlled its release. Biological assays indicated that the NaTNTQc and ZnTNTQc nanostructures decreased the viability of T24 cells after 48h at high concentrations. Furthermore, the clonogenic assay showed that NaTNT, NaTNTQc, ZnTNT and ZnTNTQc combined with 5Gy reduced the formation of polyclonal colonies of T24 cells after 48h. The results suggest that the nanostructures synthesized in this study interfere in cell proliferation and can therefore be a powerful tool in the treatment of bladder cancer.

Synthesis of hybrid materials by immobilizing para-aminobenzoic acid complexes of Eu3+ and Tb3+ in zeolite Y and their luminescent properties

Two new lanthanide containing zeolite Y based luminescent hybrid materials were synthesized and characterized. Exchange of Na+ from zeolite Y with lanthanide ions (Eu3+ or Tb3+) was carried out by ultrasonication and annealing. Para-amino benzoic acid was introduced to the ion exchanged zeolite Y to form complex with the lanthanide ion. Characterizations of the materials were carried out using IR spectroscopy, PXRD, SEM, UV–Vis absorption spectroscopy, TG–DTA and DSC analysis. Luminescence properties of these materials were studied using photoluminescence spectroscopy. Complex formation inside the zeolite cage increased the luminescence efficiency of the lanthanide ions through antenna effect. Tb3+ containing hybrid material showed efficient energy transfer due to the optimal energy level matching of the triplet level of ligand and the emissive level of Tb3+. Zeolite Y structure acts as a protective barrier against the degradation of organic part as is evident from the high thermal stability of the materials.

IR and NMR Studies of the Status of Al and Acid Sites in Desilicated Zeolite Y.

The desilication of zeolite Y (of Si/Al = 31) that was previously dealuminated by steaming and acid treatment was studied. Desilication of zeolites of high Si/Al module in alkali solutions extracts both Si and Al from zeolite crystals, but while Si remains in solution, Al is reinserted into the zeolite grain. The main goal of our study was to follow the status of Al reinserted into zeolite during the desilication procedure, and its role in the formation of acid sites of the Brønsted and Lewis types. The properties of Al were followed by 27Al MAS NMR spectroscopy (for parent samples and zeolites treated either with NaOH or NaOH/tetrabutylammonium hydroxide), whereas the acid sites generated in the final stages were studied by IR spectroscopy with NH3 and CO as probe molecules. In non-desilicated zeolite, most of the Al was in a typically zeolitic tetrahedral coordination, while both NMR and quantitative IR studies of NH3 sorption evidenced that Al that was extracted by desilication and was subsequently reinserted had a tetrahedral coordination similar to amorphous aluminosilicates and showed an ion exchange ability. After the exchange of Na+ to NH4+ and decomposition of NH4+ ions, reinserted Al forms generated protonic sites from which some condensed at higher temperatures producing Lewis acid sites (with stoichiometry typical for zeolites i.e., the condensation of two protonic sites produces one Lewis site) but some other kept their character.