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Present work reports the synthesis of zirconium phosphate nanoparticles containing dirhenium(III) substance bis-dimethylsulfoxide- cis-tetrachlorodi-μ-pivalatodirhenium(III) with formula cis-Re2(C(CH3)3COO)2Cl4 ∙ 2DMSO (I) and θ-zirconium phosphate with formula θ-Zr(HPO4)2 ∙ 6H2O (ZrP). The intercalation process was monitored by EAS. Due to the spectral characteristics of the quadruple bond the conclusion was made that the obtained intercalated compounds had cis-configuration of ligands around cluster dirhenium fragment. The proposed mechanism of intercalation includes the substitution of the axial ligands of I by phosphate groups of ZrP first on the surface of ZrP, than in the inner layers. Two received products of the intercalation were characterized by SEM, XRPD, FT-IR, TGA analysis witnessing about successful intercalation process. The formation of new phases with interlayer distances of 10.53-16.6 A was found, the average size of obtained platelets was 100-200 nm. [ABSTRACT FROM AUTHOR]

The crystal-chemical approach has been applied to design materials with regulated thermal expansion. To that end, model simulations have been performed for compositions of phosphates that yield solid solutions of the following type Na1 + 2xZr2 –xCux(PO4)3 and Ca0.5 +xZr2 –xCux(PO4)3, 0.1 ≤ x ≤ 0.5 with the expected structure of NaZr2(PO4)3 (NZP). The new phosphates have been prepared by solid-state reactions and characterized by X‑ray diffraction, IR spectroscopy, and scanning electron microscopy. The compounds have been shown to crystallize in the NZP structure, with a particle size from 0.1 to 1 μm. The thermal expansion of the compounds has been studied by high-temperature X-ray diffraction in the temperature range from 25 to 700°C. Linear, average, and volume coefficients of thermal expansion and anisotropy of thermal expansion have been calculated and analyzed in relation to composition of Na, Zr, Cu and Ca, Zr, Cu phosphates in the studied sets. [ABSTRACT FROM AUTHOR]

ZHS@ Mg‐Al‐LDH and ZHS@α‐ZrP hybrid materials were prepared by electrostatically loading zinc hydroxystannate (ZHS) on the layered compounds (Mg‐Al‐LDH and α‐ZrP) in this work. With the addition of 2 wt% of the two hybrid materials to epoxy resin (EP), respectively, the fire hazard of EP and its composites were investigated. The limiting oxygen index (LOI) of ZHS@ Mg‐Al‐LDH/EP composite increased by 19.0% compared with pure EP, while its peak heat release rate (PHRR), total heat release rate (THR), and peak smoke release rate (SPR) decreased by 48.2%, 20.8%, and 21.6%, respectively, evidenced by the results of the LOI test and cone calorimetry test (CCT). The LOI of ZHS@α‐ZrP/EP composite increased by 20.4%, and its PHRR, THR, and SPR decreased by 47.7%, 21.4%, and 27.1%, respectively. Both hybrid materials showed prominent flame retardant and smoke suppressing properties. In addition, through the analysis of the TG‐IR and Raman spectrum of residual char, the specific mechanism of flame retardance and smoke suppression was explored. [ABSTRACT FROM AUTHOR]

The electrochemical oxygen evolution reaction (OER) is the half-cell reaction for many clean-energy production technologies, including water electrolyzers and metal–air batteries. However, its sluggish kinetics hinders the performance of those technologies, impeding them from broader implementation. Recently, we reported the use of zirconium phosphate (ZrP) as a support for transition metal catalysts for the oxygen evolution reaction (OER). These catalysts achieve promising overpotentials with high mass activities. Herein, we synthesize ZrP structures with controlled morphology: hexagonal platelets, rods, cubes, and spheres, and subsequently modify them with Co(II) and Ni(II) cations to assess their electrochemcial OER behavior. Through inductively coupled plasma mass-spectrometry measurements, the maximum ion exchange capacity is found to vary based on the morphology of the ZrP structure and cation selection. Trends in geometric current density and mass activity as a function of cation selection are discussed. We find that the loading and coverage of cobalt and nickel species on the ZrP supports are key factors that control OER performance. [ABSTRACT FROM AUTHOR]

A two-step intercalation and surface modification procedure was used to synthesize heterofunctional zirconium phosphates (ZrP) with different groups in the interlayer and on the surface. The relationship of the interlayer and surface was then investigated through evaluation of the stability and reactivity of heterofunctional ZrP materials by thermal analysis. Intercalated samples were prepared by the ion-exchange mechanism with variation in the loading, charge, and size of ions. An identical epoxide was used to modify the surface in all investigations. It was found that the two-step procedure could be performed in either order to prepare heterofunctional ZrP materials. In both cases, the contents of the interlayer were found to impact the reactivity of the surface and stability of covalently attached surface groups, with higher interlayer loadings leading to decreased stability and reactivity of surface phosphates. [ABSTRACT FROM AUTHOR]

In confined space with length scale of several nanometers, the phase behavior of matter, e.g., nucleation and crystallization, is completely different from its analogue in bulk. However, in environmental applications, the relationship between the nanoconfined crystallization behavior of inorganic crystals and their properties for pollutant removal is rarely elucidated. Herein, an unusual formation of zirconium phosphate (ZrP) crystals as a mixture of both thermodynamically stable α‐ and metastable γ‐phases inside the nanoconfinement of 7.9 nm pores of mesoporous polystyrene (MPS) is reported. This consequently changes the interaction between ZrP and toxic metal cations from nonspecific electrostatic attraction of normal α‐ZrP to highly specific inner‐sphere coordination of nanoconfined γ‐ZrP, which exhibits remarkable reactivity as well as reusability for the removal of toxic metals. The results of this study contribute to a better understanding of the use of nanoconfinement for the regulation of material properties. [ABSTRACT FROM AUTHOR]

A composite membrane was synthesized by functionalizing the Polytetrafluoroethylene film with inorganic Zirconium Phosphate and polyvinyl alcohol. The hybrid method of pore infiltration and layer by layer coating was adopted to obtain the membrane. Hydrophilicity of the PTFE support was increased by chemical treatment. The proton conductivity of the membrane was increased considerably by using chemically treated hydrophilic support. The composition of ZrP and PVA in the solution (sol) was optimized with respect to methanol crossover and proton conductivity. The top view of the membrane surface morphology was observed by using SEM and EDX revealed the presence of 31.9% Zirconium and 26.44% Phosphate in the synthesized membrane. The membrane top layer functional groups were analyzed by FT-IR and the spectra confirm the incidence of functional groups related to ZrP and PVA. Thermal stability of the membrane was analyzed using TGA-DTA and it was stable up to 140 °C. The membrane was mechanically stabile with a mechanical strength of 44 MPa. The membrane possessed proton conductivity of 28.1 mS cm−1 and low methanol permeability (14.5 × 10-7 cm2 s−1) at 80 °C. Image 1 • PTFE-ZrP-PVA composite membrane was synthesized for high temperature DMFC. • The methanol permeability of the membrane ∼3 times lower than that of Nafion117. • The membrane is mechanically and thermally stable for commercial applications. • Enhancement of membrane properties were attained at higher temperatures up to 80 °C. • The PTFE-ZrP-PVA membrane is economical to use in DMFC. [ABSTRACT FROM AUTHOR]

Samples of zirconium titanium phosphate inorganic ion exchangers with different Zr : Ti molar ratios were synthesized. The samples were characterized using FT-IR spectroscopy, X-ray diffraction, scanning electron microscopy, and pore size analysis. The adsorption behavior of lanthanide isotopes 141Ce(III), 160Tb(III), and 169Yb(III) was studied in batch experiments. The influence of the V/m ratio (mL g–1), solution pH, contact time, particle size, metal ion concentration, and temperature on the adsorption kinetics was studied. The changes in the Gibbs free energy, enthalpy, and entropy were calculated. The adsorption isotherms and kinetics were analyzed using different models. The adsorption was found to follow the Langmuir isotherm better than the Freundlich isotherm. The pseudo-second-order kinetic model fits the adsorption data. [ABSTRACT FROM AUTHOR]

Zirconium-based materials are efficient adsorbent for aqueous phosphate removal. However, current zirconium-based materials still show unsatisfied performance on adsorption capacity and selectivity. Here, we demonstrate a zirconium hydroxide encapsulated in quaternized cellulose (QC–Zr) for the selective phosphate removal. Zirconium hydroxide nanoparticles were simultaneously generated in situ with the QC framework and firmly anchored in the three-dimensional (3D) cross-linked cellulose chains. The maximum P adsorption capacity of QC–Zr was 83.6 mg P/g. Furthermore, the QC–Zr shows high P adsorption performance in a wide pH range, generally due to the electrostatic effects of quaternized cellulose. The enhanced adsorption of P was also achieved in the presence of competing anions (including Cl−, NO 3 −, SO 4 2 − , SO 4 4 − ) and humic acid (HA) even at a molar ratio up to 20 levels. The column adsorption capacity of QC–Zr reached 4000 bed volumes (BV) at EBCT = 0.5 min as the P concentration decreased from 2.5 to 0.5 mg/L. Mechanism study revealed that both –N+(CH 3) 3 groups and zirconium hydroxide were involved in phosphate adsorption via electrostatic interactions between –N+(CH 3) 3 and phosphate, and the formation of zirconium hydrogen phosphate (Zr(HPO 4) x). The 31P nuclear magnetic resonance (NMR) study implied that P surface–precipitated and inner–sphere complexed with zirconium hydroxide at a ratio of 3:1. Image 1 [ABSTRACT FROM AUTHOR]

The chitosan based nanohydrogel reinforced nanocomposite was fabricated by facile sol–gel polymerization technique. A chitosan-cl-poly(AA)/ZrPO 4 nanocomposite was discovered as a capable photocatalyst for the elimination of rhodamine dye. The designed chitosan-cl-poly(AA)/ZrPO 4 nanocomposite was examined by various characterization approaches such as Scanning electron microscopy (SEM), X-Ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and Transmission electron microscopy (TEM). The photocatalytic experiment outcomes revealed that the nanocomposite had good remediation potential as 82% of rhodamine B dye was remediated within 3 h of process. The antimicrobial behavior of nanocomposite was studied against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus bacteria. Cell toxicity of the synthesized chitosan-cl-poly(AA)/ZrPO4 nanocomposite was performed against Vibrio fischeri as model organism. The chitosan-cl-poly(AA)/ZrPO 4 nanocomposite demonstrated the potential antibacterial behavior. [ABSTRACT FROM AUTHOR]

The trivalent lanthanide-actinide separations are a major challenge in reprocessing of nuclear fuels. To achieve this, commonly organic extractants and solvents are utilized in elaborate processes. Here we report a simple new method that can perform a supportive or alternative role. A nanocrystalline α-zirconium phosphate ion exchanger was utilized for Eu(III)/Am(III) column separation. Comprehensive preliminary studies were done using batch experiments to optimize the final separation conditions. The distribution coefficients for Eu were determined as a function of pH (from 0 to 3) and salinity (Na, Sr). The distribution coefficients for Am were determined as a function of pH, and Eu concentration, from 1:40 to 10,000:1 Eu:Am molar ratio. The exchanger always preferred Eu over Am in our experimental conditions. Separation factors (Eu:Am) of up to 400 were achieved in binary Eu-Am solution in pH 1. The breakthrough capacity was determined in dynamic column conditions using Eu: 0.3 meq•g-1, which is approximately 4% of the theoretical maximum capacity. Two types of hot column separation tests were conducted: (i) binary load (selective Am elution), and (ii) continuous equimolar binary feed. In both cases separation was achieved. In (i), the majority (82% of the recovered 93%) of Am could be purified from Eu with extremely high 99.999% molar purity, while alternatively even more (95% of the recovered 93%) at a lower purity of 99.7 mol %. In (ii), up to 330 L•kg-1 of the equimolar solution per mass of the exchanger could be treated with Am purity above 99.5 mol % in the total eluate. Alternatively, up to 630 L•kg-1 above 95 mol %, or up to 800 L•kg-1 above 90 mol % purities. [ABSTRACT FROM AUTHOR]

The dense NaZr 2 (PO 4) 3 (NZP) ceramics were successfully prepared by a microwave sintering process with x wt.% ZnO as a sintering aid (where x = 0, 0.5, 1.0, 2.0 and 3.0). The effects of ZnO additive on the crystal structure, microstructure and sintering behavior of as-prepared NZP ceramics were systematically investigated. The single NZP phase can be achieved in the wide temperature range of 900–1200 °C holding for 2 h by microwave-sintering technology. The addition of ZnO sintering aid would not noticeably change the crystal structure of NZP. Importantly, ZnO additive significantly promoted the densification and 1.0 wt% ZnO-added sample possessed the maximum relative density of 96.5% after sintering at 1100 °C, considerably higher than that of pure NZP sample. Besides, the Vickers hardness of the above sample could attain near 800 MPa, which is about four times as hard as the pure NZP ceramics without ZnO additive. It was suggested that the combination of microwave sintering with appropriate addition of ZnO sintering aid would provide a convenient and efficient method for rapid fabrication of dense NZP ceramics. [ABSTRACT FROM AUTHOR]

A novel organo-modified α-zirconium phosphate was prepared by intercalating a functional 1,2,2,6,6-pentamethyl-4-(phenyldiethoxysiloxy) piperidine into α-ZrP. The structure of functional α-ZrP (IZrP) was characterized by X-ray diffraction, FTIR and SEM. The thermal stability of the silicon rubber (SR) composite obtained by physically mixing IZrP was investigated by TGA and DSC. The results shown that the maximum decomposition temperature (Tmax) of SR/IZrP composites increased from 514 to 540 °C as the IZrP loading increased from 0 to 5 mass% and a reduction in exothermic enthalpy from 3378 to 1520 J g−1 was observed. The maximum exothermic peak temperature had obvious enhancement from 557 to 593 °C, while in SR/IZrP/AlOH the deteriorated thermal stability was observed at T0.1 when compared with SR/IZrP. The addition of AlOH into SR/IZrP increased the exothermic enthalpy, prolonging the exothermic process and increasing the maximum exothermic peak temperature. The SEM results revealed that IZrP and AlOH were dispersed in SR with the layered structure. [ABSTRACT FROM AUTHOR]

Coil-like transition metal zirconium phosphate (MZr(PO4)2·4H2O, M = Co2+, Ni2+, and Cu2+, named as ZPM) microspheres were prepared by microwave irradiation heating method under the conditions of low temperature and normal atmosphere. The microspheres were investigated by using FESEM, XRD, and XPS. The possible way of combination between M2+ and phosphate was proposed based on the characterization results. The electromagnetic parameters of ZPM were measured by the vector network analyzer, and then, the reflection loss (dB) was calculated to evaluate the absorption performance of these microwave absorbers. The results indicated that ZPCo possessed better absorption performance compared with ZPNi and ZPCu, whose minimum value of reflection loss can reach − 2.66 dB (14.8 GHz). [ABSTRACT FROM AUTHOR]

Polyamide-6/organointercalated zirconium phosphate nanocomposites (PA-6/ZrPOct) were prepared by melt extrusion. The synthesized lamellar ZrP was expanded with octadecylamine at different amine:phosphate ratio, and its influence was evaluated by tensile test, melt flow rate, water absorption, rheology, scanning electron microscopy, and wide-angle X-ray diffraction. For all nanocomposites, the increase of modulus and decrease of elongation at rupture were observed. The decrease in water uptake was observed as the amine/phosphate increase, indicating that the presence of the amine reduces the hydrophilic nature of PA-6. Rheology revealed by pseudoplasticity indices that the nanofillers dispersion was homogeneous in all nanocomposites. Wide-angle X-ray diffractometry analysis showed that the characteristic basal spacing peak of pristine ZrP was absent for ZrOct 1:1 and 2:1. Also a high decrease in crystallinity was observed for PA-6/ZrOct 2:1 sample, which would be associated to plasticizing effect of octadecylamine avoiding crystallites formation. Evidences showed that structures with different degrees of intercalation and/or exfoliation could have been achieved. [ABSTRACT FROM AUTHOR]

Hygroscopicity can be understood as ability of any material to absorb water. This investigation aims to study the effect of lamellar zirconium phosphate (ZrP) in the hygroscopicity of poliamide-6 (PA-6). In situ (PA-6/ZrP) nanocomposites were prepared during the polymerization of caprolactam. Structural, thermal, crystallographic and rheological characteristics were assessed by infrared spectroscopy (FTIR), thermogravimetry, differential scanning calorimetry, wide-angle X-ray diffraction (WAXD), rheological and water absorption measurements. FTIR evidenced strong interaction between polymer/nanofiller. According to the kind of nanofiller, changes in PA-6 thermal stability and crystallinity degree were noticed. Formation of PA-6 α-crystal, microcomposite and possibly exfoliated nanocomposite was predicted by WAXD. Rheological measurements evidenced great interaction between PA-6 and nanofillers. PA-6 hygroscopicity was strongly influenced by ZrP-attained value almost 40% lesser as compared to neat PA-6. [ABSTRACT FROM AUTHOR]

Although lithium–sulfur batteries are promising environmentally friendly and low‐cost energy storage devices with high energy densities, many obstacles such as poor conductivity, volume expansion and the "shuttle effect" still limit their large‐scale commercialization. In this work, a 2D sandwich‐like α‐ZrP/polypyrrole (α‐ZrP/PPy) material with a nanosheet structure was designed as a sulfur host. The material can provide unique ion transfer channels for the rapid transfer of Li+ ions and catalytically promote the conversion of lithium polysulfides (LiPSs). Moreover, the α‐ZrP nanosheets provides a true covalent anchor for sulfur species, whereas the PPy builds a physical barrier and forms a conductive network for accelerating the electron transport and promoting the electrochemical performance. In addition, the moderate catalytic activity and true sulfur confinement effect of α‐ZrP were confirmed by experiments and theoretical calculations. The α‐ZrP/PPy@S cathode exhibits a highly reversible capacity of 727.2 mAh g−1 even at a high current density of 5 C, offering a novel cathode material for high performance Li–S batteries. [ABSTRACT FROM AUTHOR]

• Rhodium oxide nanoparticles on zirconium phosphate support. • Synthesized catalyst was utilized for hydroformylation-acetalization reaction. • Regioselectively Linear cyclic acetals (60–99%) with 96–100% conversion were obtained. • Ligand and additive-free synthesis of acetals. • Synthesis of important fuel additive (2-ethyl 1,3 dioxolane). A novel sustainable approach for the synthesis of 2-ethyl 1,3 dioxolane and various short to long-chain or aromatic cyclic acetals through a tandem hydroformylation-acetalization reaction using Rh oxide nanoparticle supported on zirconium phosphate has been established. The Rh oxide nanoparticle supported on zirconium phosphate was synthesized and characterized by various physicochemical methods. The SEM and TEM analysis revealed the average particle size of rhodium oxide was found to be ∼7.56 nm in 2%Rh@ZrP catalyst. Furthermore, the synthesized catalyst was employed to carry out a tandem hydroformylation reaction in a green solvent (ethylene glycol). Experimental results demonstrated that 2 wt.% of Rhodium on zirconium phosphate efficiently activated olefins, leading to the selective formation of cyclic acetals (60–99%) at 80°C for 6 h. In this cascade reaction, significant selectivity towards the desired product, linear cyclic acetals was observed for styrenes. This can be attributed to highly dispersed Rh oxide nanoparticles and plentiful acidic sites on the zirconium phosphate supports, which played a crucial role in tandem hydroformylation and acetalization reactions. The catalyst exhibited the ability to be reused three times without losing significant catalytic activity or selectivity. This is the first report on the synthesis of a fuel additive and other cyclic acetals via a tandem hydroformylation-acetalization reaction using heterogeneous catalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

Alkaline phosphatase (ALP) is a major biomarker for clinical diagnosis, but detection methods of ALP are limited in sensitivity and selectivity. In this paper, a novel method for ALP determination is proposed. A photoelectrochemical (PEC) sensor was prepared by growing UiO−tetratopic tetrakis (4-carbox-yphenyl) porphyrin (TCPP) in situ between layered Ti 3 C 2 through a one-pot hydrothermal method. The obtained Schottky heterojunction photoelectric material Ti 3 C 2 @UiO−TCPP not only has a large light absorption range but also greatly improves the efficiency of photogenerated electron hole separation and thereby enhances sensitivity for PEC detection. The phosphate group on the phosphorylated polypeptide was utilized to form a Zr–O–P bond with the zirconium ion on UiO-66, and then photocurrent decreases due to the steric hindrance effect of phosphorylated polypeptides, that is, the hindrance of electron transfer between the photoelectric material and a solution. The specific interaction between ALP and phosphorylated polypeptides shears the bond between phosphate and zirconium ion on UiO-66 in the peptides then weakens the hindrance effect and increases the photocurrent, thus realizing ALP detection. The linear range of ALP is 0.03–10,000 U·L−1, and the detection limit is 0.012 U·L−1. The method is highly sensitive and selective, and has been applied in detection of ALP in serum samples. [Display omitted] • A novel photoelectrochemical sensor based on Ti 3 C 2 @UiO-TCPP Schottky heterojunction was developed. • Alkaline phosphatase (ALP) was determined indirectly by the steric hindrance effect produced by phosphorylated peptides. • The detection limit of ALP activity was 0.012 U · L−1, which is the lowest among the reported methods. • The sensor has been used for the detection of human serum samples with good selectivity. [ABSTRACT FROM AUTHOR]

• SAP based glass-ceramics with NZP phase were prepared by a melt-quenching process. • ZrO 2 improves the formation of NZP phase but restrains AlPO 4 phase formation. • Reasons on the formation of NZP due to ZrO 2 and B 2 O 3 addition were revealed. • Addition of ZrO 2 and B 2 O 3 induces the transformation of Q1 to Q0 phosphate units. • The SAP based glass-ceramics are potential matrices for specific HLW immobilization. Stable sodium-aluminophosphate (SAP) based glass-ceramics with sodium zirconium phosphate (NZP) crystalline phase for high-level nuclear waste (HLW) immobilization were prepared by a melt-quenching process, and the effects of ZrO 2 and B 2 O 3 on their phase composition, structural features and properties were discussed in detail. The results show that the SAP based glass-ceramics obtained by the melt-quenching process show good aqueous durability and thermal stability. ZrO 2 addition improves the formation of NZP phase but restrains the crystallization of AlPO 4 phases. It is found that the correct ratios of ZrO 2 and B 2 O 3 allow only phase formation of NZP within the SAP glass, and the reasons were also analyzed. The conclusions demonstrate that the SAP based glass-ceramics with NZP phase as the crystalline phase are the potential matrices for specific HLW immobilization, and suggest that the melt-quenching process is an applicable way to prepare certain glass-ceramic waste forms. [ABSTRACT FROM AUTHOR]

[Display omitted] • New high-sensitivity flattened balloon-shaped plastic optical fiber (FBPOF) sensor design has been proposed. • The design underwent optimization for enhanced efficiency as an absorption sensor, using COMSOL. • The optimised design FBPOF was coated with g-C 3 N 4 /ZrPO 4 to detect NO 2 − ions. • The proposed design exhibited an LOD of 182 ppb and a sensitivity of 0.03204 µA/µM. • Selectivity for NO 2 − ions, and temperature insensitivity are also shown. The fabrication and characterization of a flattened balloon shaped fiber optic nitrite sensor using zirconium phosphate supported on graphitic carbon nitrite nanocomposites (g-C 3 N 4 /ZrPO 4) as a cladding material have been reported. To design the sensing probe, a small portion of the fiber is mechanically hot pressed for flattening and then structured into a balloon shape. The improved sensitivity of the proposed design is ascribed to the better light extraction efficiency to the cladding in the flattened region of the balloon shaped fiber compared with a similar non flattened structure which is explained using numerical simulation. To demonstrate the sensing behavior of the proposed design, a NO 2 − ion sensing probe is fabricated by coating g-C 3 N 4 /ZrPO 4 nanocomposite over the flattened portion of the balloon shaped fiber. Experimental results on sensing exhibit a limit of detection (LOD) of 182 ppb and sensitivity 0.03204 µA/µM for NO 2 − ion. Further, the study is extended towards showing high specificity and fair temperature invariance of the proposed sensor which indicates its improved performance. [ABSTRACT FROM AUTHOR]

Dihydroxyacetone isomerization is a fundamental reaction for the production of lactic acid using different feedstocks. However, achieving excellent catalytic activity and resistance against leaching in water is challenging. Herein, we devised a Sn doped zirconium phosphate as effective heterogeneous catalyst. The incorporation of Sn could remarkably aggrandize the content of strong Lewis acid sites while retain relatively high surface areas. Gratifyingly, this catalyst exhibits enhanced activity and reusability for selective dihydroxyacetone isomerization into lactic acid with water as solvent. High lactic acid yields of 70.30 and 76.25% were achieved in water and water/acetone under optimal reaction conditions, respectively. The composition and activity of catalyst are reserved with reduced ions leaching. The excellent catalytic performance is attributed to accelerated conversion of pyruvaldehyde to lactic acid by the strong Lewis acid sites. Nuclear magnetic resonance revealed that the reaction is proceeded via a keto-enol tautomerization process. [Display omitted] • Sn doped zirconium phosphate catalyst is effective for the isomerization of dihydroxyacetone to lactic acid. • High LA yields of 70.30 and 76.25% were achieved in water and water/acetone, respectively. • The composition and activity of catalyst can be reserved with little leaching. • The conversion of DHA to LA is proceeded via a keto-enol tautomerization process. [ABSTRACT FROM AUTHOR]

Commercializing direct methanol fuel cells (DMFC) demands cost-effective cation exchange membranes. Herein, a polymeric blend is prepared from low-cost and eco-friendly polymers (i.e., iota carrageenan (IC) and polyvinyl alcohol (PVA)). Zirconium phosphate (ZrPO4) was prepared from the impregnation–calcination method and characterized by energy dispersive X-ray analysis (EDX map), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM), then incorporated as a bonding and doping agent into the polymer blend with different concentrations. The new fabricated membranes were characterized by SEM, FTIR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and XRD. The results revealed that the membranes’ physicochemical properties (oxidative stability, tensile strength) are enhanced with increasing doping addition, and they realized higher results than Nafion 117 because of increasing numbers of hydrogen bonds fabricated between the polymers and zirconium phosphate. Additionally, the methanol permeability was decreased in the membranes with increasing zirconium phosphate content. The optimum membrane with IC/SPVA/ZrPO4-7.5 provided higher selectivity than Nafion 117. Therefore, it can be an effective cation exchange membrane for DMFCs applications.

Abstract Two-dimensional (2D) inorganic layered nanoplatelets exhibit superior lubricating properties in both solid states and oil dispersions. In this paper, we have systematically investigated the effects of surface and interlayer modifications on the tribological performance of layered α-zirconium phosphate (ZrP) nanoplatelets in mineral oil. The pristine layered ZrP nanoplatelets were first reacted with silanes of different alkyl chains to achieve outer surface modifications, followed by intercalation with different alkyl amines to alter the interlayer spacing. Friction and anti-wear studies on ZrP nanoplatelets with various modifications in mineral oils suggest that a longer alkyl chain on the outer surfaces along with a small increase in interlayer spacing would lead to a better tribological behavior especially under a relatively heavy load condition. Our results illustrate the ability of tuning the tribological properties of 2D layered nanoplatelets in oils by varying their surface and interlayer functionalities and would be helpful for understanding the underlying tribological mechanisms of nanolubricating oils containing 2D layered nanoplatelets. Graphical abstract ᅟ

Abstract Composite membranes were obtained by modification of heterogeneous polymer cation and anion-exchange membranes with nanoparticles of zirconium hydrophosphate and hydrated zirconium dioxide, respectively. The ion-exchange materials were investigated with the methods of electron microscopy, potentiometry, voltammetry, and impedance spectroscopy. Single nanoparticles, which were precipitated in aqueous media, form aggregates, when the composites are in a contact with polar organic solvent. Both single nanoparticles (up to 10 nm) and their aggregates (up to 200 nm) were precipitated in ion-exchange polymers in glycerol media. Non-aggregated nanoparticles improve electrical conductivity of the ion-exchange materials, the aggregates are barriers against fouling. The membranes were applied to NaCl removal from highly concentrated glycerine-water mixture containing organic additives (byproduct of biodiesel production). As opposite to pristine materials, the composites demonstrate stability against fouling.

The Co(II) complex of [Co(bpy)2(NO3)]Cl·3H2O, bpy = 2,2'-bipyridine, has been synthesised by the solution crystallisation method. The boron nitride nanosheets/silver nanoparticles/[Co(bpy)2(NO3)]Cl·3H2O nanoaggregate was prepared in order to better analyse the adsorption orientation of the cobalt complex on the surface of silver nanoparticles. The result of the surface-enhanced Raman scattering measurement indicates that the molecular plane of the cobalt complex presents a tilted orientation with respect to the surface of silver nanoparticles. The luminescence property of [Co(bpy)2(NO3)]+ two-dimensional arrangements within the layers of zirconium phosphate (ZrP) was also investigated. Steady-state luminescence spectra of the [Co(bpy)2(NO3)]+-exchanged ZrP materials show an increase in the luminescence intensity.

In order to search nanofiller for controlling release of drugs lamellar α-zirconium phosphate (α-ZrP) was modified with ether-amine oligomer (E-A). Synthesis and chemical modification followed specific reaction conditions and different EA:ZrP ratios. Infrared spectra showed strong interaction between P-OH and NH2 groups. Thermogravimetric curves showed that ether-amine oligomer was incorporated by ZrP. Interlamellar space of α-ZrP increased at least four times indicating intercalation. The relaxometry analysis indicated that α-ZrP molecular mobility changed according to the ether-amine amount. The scanning electron microscopy/energy dispersive analysis revealed the presence of octadecylamine inside the α-ZrP galleries. The results showed that P-OH group (Brønsted acid) and amine group (Brønsted base) reacted to each other, resulting in an ionic bond PO- + 3HN-[-(CH2-CH2-O)m-(CH2-C-H(CH3)-O)n-]. Partially intercalated nanofiller were achieved.

Layered zirconium phosphate (ZrP) is a versatile material with phosphate (POH ) groups able to exchange inorganic and organic cations or to intercalate basic molecules. The present review deals with the use of this material as a sorbent for heavy metal cations or dye molecules in wastewater treatments. The possibility to combine ZrP with polymers or other inorganic materials, in order to have suitable systems for real and large scale applications, was investigated, as well as the combination with photocatalytic materials to obtain hetrogeneous photocatalysts for the capture and photodegradation of organic dye molecules.

There is an increasing demand on synthesizing pharmaceuticals and biomaterials that possess antimicrobial and/or antiviral activities. In this respective silver nanoparticles are known for their excellent antimicrobial activity. Nevertheless, their uncontrolled release in a biological medium can induce a cytotoxic effect. For this, we explored the use of nanolayered metal phosphates based on titanium and zirconium as materials that can be enriched with silver nanoparticles. Employing the hydrothermal route, crystalline α-phases of zirconium and titanium phosphates (α-ZrP, α-TiP) were synthesized and there after surface-enriched with silver nanoparticles. The structural assessment confirmed the stability of the structures and their sizes are in the nanoscale at least in one dimension. The cytocompatibility assays confirmed the biocompatibility of the pristine phases and the antimicrobial assay confirmed that both silver-enriched nanolayered structures maintain an antibacterial effect at reasonably low concentrations.

In this study, commercial cellulose membranes were surface coated with alpha‑zirconium phosphate nanoparticles (α -ZrP-n) to study their impact on the overall removal efficiency of heavy metals from synthetic metal mixture wastewater solution. A total of four homogeneous solutions (0.25, 0.50, 0.75, and 1.00 wt%) of α -ZrP-n were prepared by sonicating the nanoparticles in deionized water. These solutions were used to surface coat the commercial cellulose membranes. The Scanning Electron Microscopy (SEM) along with Energy Dispersive Spectroscopy (EDS) were used to confirm the attachment of α -ZrP-n on the cellulose membrane surface. Furthermore, the structural characteristics of the α -ZrP-n modified cellulose membranes were also studied. The water contact angle results showed that all coated membranes remained super-hydrophilic. The porosity of the membranes decreased to 48% with the addition of 1.00 wt% α -ZrP-n compared to 65% for the pristine membrane. The mechanical strength has improved from 3.4 MPa for the pristine membrane to about 4 MPa for the 1.00 wt% α -ZrP-n membrane. Similarly, the thermal stability was found to be slightly enhanced as evidenced by the increase in decomposition temperature to 280 and 285 °C in the 0.75 and 1.00 wt% α -ZrP-n membranes, respectively. Furthermore, a removal efficiency of 97.0 ± 0.6, 98.0 ± 0.5, 99.5 ± 0.2, and 91.5 ± 2.0% for Cu (II), Zn (II), Ni (II), and Pb (II), respectively, was observed with the 0.50 wt% α -ZrP-n membrane. This removal was achieved at a flux of 41.85 ± 0.87 × 103 LMH. Increasing the α -ZrP-n concentration further did not show any improvement in the overall removal efficiency. However, it led to 46% flux reduction in the 1.00 wt% α -ZrP-n membrane. The mechanism of removal of the heavy metal ions was postulated to be a combination of ion exchange and electrostatic attraction of the strong negatively charged α -ZrP-n membranes and the free metal ions in the wastewater solution. Unlabelled Image • Cellulose/ α -ZrP-n ion exchange membranes were fabricated via surface coating. • Removal mechanisms of heavy metals were confirmed via membrane characterization. • Up to 97, 98, and 99% removal of Cu (II), Zn (II), and Ni (II) were achieved. • High water permeability through cellulose/ α -ZrP-n membranes was accomplished. • Cellulose/ α -ZrP-n membranes reported slight improvement in tensile strength. [ABSTRACT FROM AUTHOR]

Processing metallic powders by electrical resistance sintering requires the use of insulating ceramics dies. Selecting the appropriate ceramic material according to the electrical, thermal and mechanical properties is a need. Dies produced with several ceramic materials have been tested during the production of cemented carbide in order to check their behaviour in the process and final product properties. Tialite/mullite, zircon/mullite, zirconium phosphate based ceramic, yttria-stabilized zirconia and sialon, in most cases with modified compositions and shaping processes in order to achieve a high density, have been tested. Dry powder processing by cold isostatic pressing and furnace sintering resulted to be the better process for dies production. The effect of die properties on the produced cemented carbide, and the behaviour and life of the die during the production have been analysed. Very smooth die surface increases the number of cycles withstood during metallic parts production, because of lower extraction stresses, as checked for sialon dies. Zirconium phosphate based dies, with low thermal conductivity, show the most densified hard metal parts surface. [ABSTRACT FROM AUTHOR]

The present work reports on the morphologies and properties of anodized Zr in two different electrolytes. The Zr phosphates (α-ZP) obtained in the inorganic electrolyte containing H3PO4+NaF and zirconia (ZrO2) nanostructures formed in the organic glycerol-based electrolyte were investigated by SEM, FT-IR and AFM. The surface analysis was completed by contact angles measurements. It was found that the type of electrolyte along with the applied voltage influence the structure of the sample and being more precise, the anodic oxidation in H3PO4 electrolyte promotes the evolution of flaky structures and eventually of pores by increasing the applied voltage, while the anodizing performed in glycerol- based electrolyte results in the formation of nanoporous structures that evolve into nanotubes as the applied voltage grows. Based on experimental data a film forming mechanism for α-ZP and ZrO2 was proposed and correlated to analyzed surface properties. [ABSTRACT FROM AUTHOR]

This paper aims at giving a historical perspective on the work made at Perugia University in the field of proton conducting materials based on layered phosphates, phosphonates and organophosphates, and at commemorating Professor Giulio Alberti, one of the most authoritative scientists who pioneered this research field. Due to high chemical inertia and good thermal stability, layered zirconium phosphate (ZP) was investigated as a proton conductor since mid 80s, but it was soon clear that the conductivity was too low for application in electrochemical devices working at high current densities. Attempts to enhance the ZP conductivity led first to the development of intercalation compounds with aliphatic or aromatic amines and then to the synthesis of ZP organic derivatives (zirconium phosphonates) where acidic functions, such as carboxylic or sulfonic groups, were covalently anchored to the ZP layers through alkyl or aryl groups. Although with both types of materials it was possible to enhance to a great extent the conductivity of ZP, low thermal or hydrolytic stability prevented their use as fillers of ionomeric membranes for fuel cell application. On the other hand, ZP based nanofillers, bearing hydrophobic groups anchored to the ZP layers, turned out to be suitable to improve both mechanical properties and, surprisingly, conductivity of perfluorosulfonic acid ionomers (PFSA). Moreover, the combined use of such hydrophobic materials and hydrophilic ZP as PFSA fillers led to more effective mechanical reinforcement and to better fuel cell performance than that achieved by single filler membranes. • Structural features of layered Zr phosphate (ZP) and phosphonates (ZPhs). • Highly anisotropic conductivity in fully inorganic ZP sheets. • Conductivity of amine intercalated ZP in relation to amine basicity and mobility. • Proton transport in ZPhs bearing amine, carboxy and sulfonic functions. • Conductivity and mechanical properties of ionomer-ZP or -ZPhs composite membranes. • Synergistic PFSA reinforcement by combined use of ZP and hydrophobic ZPh fillers. [ABSTRACT FROM AUTHOR]

The nanocomposite layer with ZrP 500, which has good dispersion, orientation, and barrier properties, produced greatly improved performance compared to the original inorganic layer. • Zirconium phosphates (ZrPs) could be synthesized at various sizes and aspect ratios to be used for epoxy-ZrP nanocomposites formation for enhancement of the barrier properties. • The size of ZrP could be controlled by the concentration of phosphoric acid for both reflux and hydrothermal methods, and hydrothermal method could achieve the wider range of size, i.e. from 50 nm to 1600 nm. • The optimum size of ZrP was 500 nm with maximum aspect ratio of 250, with which the lowest WVTR of the epoxy-ZrP nanocomposite was achieved at 3.67 × 10−4 g/m2/day, while maintaining optical transmittance. Zirconium phosphate (ZrP) was prepared at various sizes and aspect ratios to be used for epoxy-ZrP nanocomposites formation for enhancement of the barrier properties. ZrP syntheses were performed at various concentrations of phosphoric acid via reflux and hydrothermal methods. The synthesized ZrP was modified using Jeffamine M1,000 to increase the interlayer distance and compatibility with polymer. Epoxy-ZrP nanocomposite layers were coated on sputtered PET substrates to improve the barrier properties. The dispersed and arranged ZrP structure was confirmed by transmission electron microscopy (TEM). The water vapor transmission rate (WVTR) was decreased after nanocomposite coating on sputtered PET substrate with increased ZrP size, which dramatically improved the barrier performance. Optimum size of ZrP was 500 nm which increased the aspect ratio to 250, and its composite coating achieved the WVTR value down to 10−4 g/m2/day from sputtered PET (10-2 g/m2/day) substrate before composite coating. The lag time was measured at over 100 h with the Ca cell test under conditions of 85℃ and 85% RH. Optical properties were little affected by an increase in the size of ZrP and were similar to those of sputtered PET substrates. [ABSTRACT FROM AUTHOR]

An electroactive and chemically stable composite was obtained from zirconium (IV) isopropoxide (ZrI) and phosphoric acid (ZrP). The ZrP was characterized by techniques such as Fourier transform infrared spectroscopy, 13C and 31P nuclear magnetic resonance, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy, surface area and porosity and cyclic voltammetry. Voltammetric behaviour of the ZrP was obtained using of a modified graphite paste electrode in a potential range from − 0.20 to 1.00 V (vs Ag/AgCl). ZrP showed one redox couple with average potential E θ ′ = 0.30 V (vs Ag/AgCl(sat.)) (40% w/w; v = 20 mV s−1; KCl; 1.00 mol L−1). It was tested on electrocatalytic detection of ascorbic acid using cyclic voltammetry and square wave voltammetry. The modified electrode showed a detection limit of 2.4 × 10−5 mol L−1, with relative standard deviation of ± 3% (n = 3) and amperometric sensitivity of 11.7 mA/mol L−1 (R = 0.999) by using the cyclic voltammetry technique and a detection limit of 1.10 × 10−4 mol L−1 with relative standard deviation of ± 2% (n = 3) and amperometric sensitivity of 126.9 mA/mol L−1 (R = 0.998) by using the square wave voltammetry technique. [ABSTRACT FROM AUTHOR]

In this study, the sorption behavior of yttrium and strontium onto Dowex-S/S and synthesized zirconium titanium phosphate as cation exchanger from nitric acid medium was investigated using batch technique. The synthetic exchanger has been characterized by different analytical tools. Distribution behavior of Sr(II) and Y(III) as a function of HNO3 concentration in the range 0.001–3.0 M has been studied. The maximum separation value was ( α Sr Y = 18.78) at 0.001 M HNO3 and 298 K while increasing temperature decreases the separation value. The sorption kinetics data followed the pseudo-second order model and thermodynamic data indicated an endothermic and spontaneous process. [ABSTRACT FROM AUTHOR]

Abstract α-zirconium phosphate is widely used as a solid acid catalyst or a catalyst support. In this work, layered crystalline α-zirconium phosphates were synthesized via a facile hydrothermal method and applied in the synthesis of solketal from acetalization of glycerol with acetone. It was found that ZrP-200 (layered α-zirconium phosphate that calcined at 200 °C) is highly active and selective among the tested catalysts. ZrP-200 exhibits both high catalytic efficiency (with an 85.7% conversion of glycerol and a 98.6% selectivity of solketal at 50 °C and 3.0 h) and excellent stability even under mild condition. A series of characterizations results disclose that the performance of ZrP catalysts depends mainly on its surface density of acid sites. Graphical abstract Unlabelled Image Highlights • Layered Zr(HPO 4) 2 ∙H 2 O was synthesized via a facile hydrothermal method. • Zr(HPO 4) 2 was active for the formation of solketal via glycerol at 50 °C. • The yield of solketal increased with the surface density of acid sites in catalyst. • The yield of solketal reached 84.5% (with a 85.7% conversion of glycerol) at 50 °C. [ABSTRACT FROM AUTHOR]

Sodium zirconium phosphate (NZP) was synthesized by microwave-assisted solid-state reaction method with addition of x wt.% excess Na2CO3 powders (where x = 0, 2.5, 5, 7.5, and 10). The effects of the synthesis temperature and the excess sodium content on the phase compositions of the resultant samples were systematically investigated. XRD and Raman results showed that pure NZP phase could be synthesized successfully at 1100 °C for 2 h when 5 wt.% of excess sodium was introduced. Comparing with the traditional solid-state reaction method, the microwave-assisted solid-state method with the addition of appropriate excess sodium was beneficial to the synthesis of pure NZP phase, which would provide a new idea of achieving the low-temperature rapid synthesis of compounds of NZP family. [ABSTRACT FROM AUTHOR]

Abstract How to effectively enhance the flame retardancy of polyamide 46/polyphenylene oxide (PA46/PPO) alloy is one of the key issues needed to be addressed. In this work, organic-modified zirconium phosphate (OZrP) nanosheet was incorporated with PU-coated carbon fiber (CF) to flame-retard PA46/PPO alloy. The combination of OZrP and CF showed an outstanding combination effect in improving the flame retardancy and thermal stability of PA46/PPO. With the incorporation of 2 wt% OZrP and 20 wt% CF, the peak heat release rate and peak smoke production rate of PA46/PPO were reduced by 65.6% and 86.2%, respectively. Besides, the T i (temperature at 5% weight loss) and the residue of PA46/PPO/OZrP/CF were increased by 13.2 °C and 20.9 wt%, respectively, compared with PA46/PPO. The flame-retardant mechanism was further studied and revealed: when being burned, CF acted as the skeleton to improve the strength of char; simultaneously, OZrP catalyzed the carbonization of the polymer chains on the CF surface to form a strong and compact protective char layer, which blocked the transmission of heat and combustible gases, thus effectively improved the flame retardancy of the composite. Highlights • An efficient strategy simultaneously improving the flame retardancy and mechanical properties of PA46/PPO alloy was proposed. • The synergistic mechanism of OZrP nanosheet and PU-coated carbon fiber (CF) on the flame retardancy of PA46/PPO was revealed. • OZrP catalyzed the carbonization of the polymer chains on the CF surface to form a strong and compact protective char layer. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Zirconium phosphate possesses excellent selectivity towards Sc(III). • The sorption capacity of zirconium phosphate for Sc(III) is remarkable. • Direct separation of Sc(III) and Fe(III) by zirconium phosphate was achieved. • High-purity Sc(III) fractions were obtained from bauxite residue leachates. • This method holds great potential for the recovery of Sc(III) from bauxite residue. Abstract A continuous worldwide increase in scandium (Sc) criticality leads to a quest for secondary scandium resources. Among them, bauxite residue (BR) – a waste product from alumina refineries – often contains substantial amounts of scandium. However, the complexity in BR composition drives the need for developing a selective, efficient and cost-effective process to achieve the separation and purification of scandium. Insoluble salts of tetravalent metal ions are inorganic, acid-resistant ion exchangers with well-established preparation procedures, but their potential use in rare-earth recovery and purification has not been extensively explored yet. Zirconium and titanium phosphates, both in amorphous and α-layered crystalline forms, were screened for Sc(III)/Fe(III) separation, as Fe(III) is one of the base elements in BR that is the most challenging to separate from Sc(III). The studied α-zirconium phosphate (α-ZrP, Zr(HPO 4) 2 ·H 2 O) exhibited the highest Sc(III)/Fe(III) separation factors (up to approximately 23) from HCl solutions. The metal selectivity of α-ZrP was considered to be affected by the solution pH, and the size and hydration enthalpy of the metal cations. Breakthrough curves for a binary Sc(III)/Fe(III) solution, composed of metal concentrations realistic to a typical BR leachate, revealed the selectivity of α-ZrP for Sc(III). Furthermore, chromatographic separation of Sc(III) from a real HCl leachate of BR was successfully achieved on an α-ZrP column. After a two-step elution with HCl about 60% of Sc(III) was collected in fractions without measurable Fe(III), Al(III) or other rare-earth impurities. Overall, this study highlights the possibility for direct and simplified separation of Sc(III) from a much higher concentration of Fe(III) in BR, without the need of using reducing agents. [ABSTRACT FROM AUTHOR]

The catalytic activities of various solid acid catalysts were investigated via the reaction of the direct alcoholysis from furfuryl alcohol to ethyl levulinate. The modified zirconium phosphate with sulfuric acid, prepared via a sol‐gel method, exhibited excellent catalytic performance. By controlling the S/Zr mole ratio of 0.5 at the catalyst preparation, the modified zirconium phosphate catalyst obtained catalytic activity of 97.8% EL yield and 100% FA conversion. The mechanism of enhancing catalytic activity of modified zirconium phosphate was investigated. Owing to the higher specific surface area and more Lewis and Brønsted acid sites, the modified zirconium phosphate catalyst displayed higher catalytic activity in comparison to unmodified zirconium phosphate. In addition, the modified zirconium phosphate catalyst was suitable for a broad temperature range. This modification method can provide a new way to enhance Lewis and Brønsted acidity of zirconium phosphate by adjusting S/Zr ratio rather than the P/Zr ratio. The modified zirconium phosphate with sulfuric acid (ZPS), prepared via a sol‐gel method, was used for producing ethyl levulinate (EL) from furfuryl alcohol (FA). By controlling the S/Zr mole ratio of 0.5, the ZPS catalyst achieved the maximum FA conversion of 100% and EL yield of 97.8% under the reaction conditions of 2.0 g FA, 0.2 g ZPS‐0.5, 47.0 g ethanol, 200 °C, 2 h and 0.6 MPa N2. [ABSTRACT FROM AUTHOR]

Ion-exchange encapsulation of niacin into nanocontainers on polymer matrices was performed. Dowex-50 cation-exchange resin, sulfonated polymer based on metacyclophanoctol, zirconium phosphate, and Dowex-1 strongly basic anion-exchange resin were used as matrices. The niacin encapsulation was proved by the experimental data on the material balance of niacin in the equilibrium solution and polymer and was confirmed by solid-state 13С and 15N NMR spectroscopy of the polymers. Niacin in the nanocontainers occurs in the form of cations or anions. The niacin content of the nanocontainers on Dowex-1 and Dowex-50 matrices is 33 and 64% relative to the polymer weight. Niacin was released from the nanocontainers by elution with aqueous HCl and NaCl solutions simulating the electrolyte composition of the human gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Graphical abstract To capture radioactive 90Sr from high level liquid waste (HLLW), the traditional α-ZrP was exfoliated and further modified by anchoring sulfonic groups on its surface. The novel ZrP-SO 3 H exhibited the high adsorption ability for column separation of 90Sr from radioactive solution. Highlights • A novel ZrP-SO 3 H adsorbent was obtained by exfoliating and modifying of the traditional α-ZrP materials. • ZrP-SO 3 H a larger surface area and exhibited the excellent stability under rigid application condition. • It exhibited the excellent ability for selective column separation of 90Sr from a complex radioactive solution. Abstract Excellent column packing is a precondition for efficient separation of radioactive 90Sr from high level liquid waste (HLLW). α-ZrP particles are traditionally used as column packing for capturing radioactive nuclides from HLLW due to their excellent stability and adsorption ability. However, there remains room for improvement in terms of capacity and selectivity. Here, the traditional α-ZrP column packing was exfoliated and further modified by anchoring sulfonic groups on its surface to improve its adsorption capacity for 90Sr. The resulting ZrP-SO 3 H not only retained the excellent properties of α-ZrP but also possessed a larger surface area and much more adsorption sites. Adsorption experiments indicated that ZrP-SO 3 H exhibited excellent adsorption ability for separating of Sr2+ from acidic condition, and the maximum adsorption capacity of Sr2+ fitted by a Langmuir model is 183.21 mg g−1, which is higher than that of traditional α-ZrP and other similar column packings. In addition, kinetic studies indicated that Sr2+ adsorption on ZrP-SO 3 H is fast, and surface chemical adsorption is the main interaction between Sr2+ and ZrP-SO 3 H. Remarkably, radioactive experiment proved that ZrP-SO 3 H is an excellent adsorbent, and shows good stability for high efficiency for selective removal of 90Sr under complicate radioactive environment. Our present results implied that the novel ZrP-SO 3 H is potential column packing and could be suggested as promising column packing for separation of 90Sr from HLLW. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Effect of geometrical configuration on fragmentation rate was investigated. • The flat-bottom vessel at lower horn position showed the better performance. • The spherical bottom vessel was robust for the horn position. • The size of high acoustic pressure region is an important factor. Abstract This study investigated the position of ultrasonic irradiation source and reactor geometry on fragmentation rate of a layered compound, α-zirconium phosphate (α-ZrP). By numerically solving the acoustic pressure distribution using COMSOL Multiphysics®, it is clarified the mechanism whereby the operating factors influenced the α-ZrP dispersion to make a suggestion of guideline of the process design method. Two vessels made of glass with a flat-bottom and a spherical-bottom, respectively, were used. Although the flat-bottom vessel at lower horn position showed the best performance of fragmentation, the region of high acoustic pressure field in the flat bottom vessel sharply narrowed and the transmittance became prominently low. On the other hand, no significant difference of the transmittance value in the spherical bottom vessel between the cases of low and high horn positions could be observed and the spherical bottom vessel was robust for the horn position. These results suggest that not only the magnitude of acoustic pressure but also the size of high acoustic pressure region is also an important factor and a spherical bottom vessel is one of suitable shape which gives large size of high acoustic pressure region regardless of the horn position. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Atomically precise Ag nanoclusters was intercalated in zirconium pyrophosphate. • The residual carbon on Ag cluster was very crucial for protecting Ag nanocluster from sintering. • The resulting material was highly efficient for catalytic hydrogenation. • The Ag catalyst showed excellent recyclability in hydrogenation reaction. Abstract Designing and fabricating catalysts with highly dispersed metal nanoclusters (NCs) is very crucial for achieving high activity and selectivity. In this work, all-alkynyl-protected [Ag 74 (C≡CPh) 44 ](NO 3) 2 cluster (Ag cluster) with a well-defined structure was firstly intercalated in α-zirconium phosphate (α-ZrP) through ion-exchange. Then the atomically precise Ag cluster can be immobilized robustly in the support by a sequential process of carbonization, calcination and reduction. The supported Ag cluster showed the relatively high catalytic activity (TOF=222.9-445.8 h−1) and excellent recyclability for hydrogenation of a variety of nitroaromatics, as well as the compounds with carbon-carbon double bonds even if the loading of Ag was as low as 0.72 wt.%. Zirconium pyrophosphate acts as not only a stabilizer of Ag cluster through a spatial confinement, but also an adsorption site for nitroaromatics. The residual carbon arisen from thermal decomposition of all-alkynyl ligand coordinating on Ag cluster exerted an important role in protecting Ag cluster from sintering. As a result, the intercalation of Ag cluster in the interlayer region is a promising strategy for extending their potential applications in catalysis. [ABSTRACT FROM AUTHOR]

• High expansion foam used to mitigate the vapor risk due to LNG. • Adding nanoparticles to improve foam stability. • Studying effects of heat transfer mechanisms on nanoparticle stabilized foam. • Understanding the mechanism of improved stability. Natural gas consumption has increased as it is a cleaner energy source when compared to coal or petroleum. It can be stored in its liquid form as liquefied natural gas (LNG) because it has a much lower liquid volume. This has allowed ease of storage and transportation enabling it to be used as a global commodity. In case of an incident resulting in leaked LNG, the National Fire Protection Agency (NFPA) and American Gas Association (AGA) recommend high expansion foam use to mitigate the risk due to a cryogenic vapor cloud. This work investigates the role of exfoliated zirconium phosphate (ZrP) nanoplates in stabilizing high expansion foam. Experiments performed under wind induced forced convection and thermal radiation illustrate that exfoliated ZrP nanoplates can stabilize high expansion foam. Up to 40% reduction in the foam breakage rates was observed when using exfoliated ZrP nanoplate stabilized foam. Use of this foam can increase the duration over which it needs to be replenished, while allowing rising LNG vapors to become lighter by exchanging heat with the foam and ensuring effective vapor dispersion. [ABSTRACT FROM AUTHOR]