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The paper presents the results of a study of changes in the phase composition and dielectric properties of perovskite-like composites of the LiBaZrO x type depending on the temperature of the heat treatment. According to the data obtained, the initial samples obtained by the solid-state synthesis method are a three-phase system with the dominance of the orthorhombic phase ZrO 2 , the average nanoparticle size of which consists of composites, does not exceed 90–110 nm. As a result of thermal annealing, the dependences of phase transformations, as well as the dynamics of structural ordering with the formation of core-shell structures at an annealing temperature of 1000 °C, were established. The reduction of distortions and deformations of the crystal structure as a result of thermal annealing leads to an improvement in ferroelectric properties, as well as a decrease in the Curie temperature characteristic of the maximum dielectric constant. The weak dependence of the change in the dielectric constant with increasing frequency in the temperature range exceeding the Curie temperature indicates the relaxor nature of the properties of composites. [ABSTRACT FROM AUTHOR]

• Shrinkage of latent tracks during in situ ion irradiation is observed and quantified. • Rather than alpha-particles, alpha-recoils induce significant track-shrinkage. • Zircon is more sensitive than apatite to alpha-recoil-induced track-shrinkage. • The etchable lengths of latent fission tracks can be estimated as a function of α-dose. • Alpha-recoil-induced track shortening must be considered in natural zircon. The diffusion of defects (e.g., vacancies and interstitials) and elements used for dating (e.g., He and Pb) in a mineral structure is a thermal process: This is the primary assumption used to determine the age and thermal history of minerals. For instance, thermal history reconstruction, through the number and length distribution of tracks produced by spontaneous fission of 238U, is obtained by assuming a thermal event to be the only energy source for shortening of fission tracks. Here, we report a new, non-thermal energy source that induces additional shortening of fission tracks by the irradiation of alpha-recoils from the alpha-decay of 238U and 232Th. We simulate alpha-decay induced track-shortening by combining ion accelerator irradiations with transmission electron microscopy. This allows for the first observation of track-shrinkage during in situ ion irradiation. We show that rather than alpha-particles, alpha-recoils induce a significant shortening of fission tracks by nuclear-collisions. The shortening of track-length can be quantified as a function of alpha-decay event dose. However, apatite is less sensitive than zircon to this non-thermal process. The findings exemplify the interactions among different types of self-irradiation from alpha-particles, alpha-recoils and fission-fragment nuclei in single mineral grains and have important implications for the use of zircon and apatite for radiometric dating and thermochronology. [ABSTRACT FROM AUTHOR]

• PET track-etched membranes were hydrophobized by photografting of styrene. • Influence of parameters on grafting degree were studied, optimal condition was found. • Membranes were characterized by FTIR, SEM-EDX, contact angle, LEP, XPS. • Prepared membranes were tested in DCMD of saline solutions and radioactive wastes. The work concerns the purification of saline solutions and concentration of low-level liquid radioactive wastes (LLLRW) produced from nuclear research reactor (WWR-K) by membrane distillation in direct contact configuration (DCMD) using track-etched membranes (TeMs). Poly(ethylene terephthalate (PET) TeMs were hydrophobized by UV-induced grafting of styrene. Modification of PET TeMs (pore sizes from 135 to 268 nm) at optimal conditions led to increasing of contact angle to 104°. Hydrophobic PET TeMs were investigated by XPS, FTIR, SEM, liquid entry pressure (LEP) and goniometric. Prepared membranes were tested in DCMD of saline solutions and LLLRW. The effect of membrane pore diameter, temperature, concentration on fluxes and rejection degree was studied. Salt rejection was evaluated by conductimetry and atomic emission method (for Cs, Mo, Sr, Sb, Al, Ca, Fe, K, Mg and Na). Decontamination factors of radioisotopes (for 60Co, 137Cs, and 241Am) were evaluated by gamma-ray spectroscopy. Salt rejection and decontamination factors were found to depend on pore diameter and conditions of DCMD. In most cases the degree of rejection was between 90 and 100%. Decontamination factor of 137Cs reached to 1727. [ABSTRACT FROM AUTHOR]

• Ni nanotubes were formed by template synthesis method in different conditions. • Structural changes in relation to the synthesis conditions were analyzed. • Correlation between structural and magnetic properties of Ni nanotubes was defined. This work studies the relationship between the electrochemical synthesis temperature and the potential of Ni nanotubes obtained in polyethylene terephthalate template pores with their structure and morphological peculiarities. Based on established regularities in the evolution of morphology and structural parameters, the dynamics of the Ni nanotubes main magnetic characteristics are analyzed. [ABSTRACT FROM AUTHOR]

Microcrystalline CeO 2 , ThO 2 , and UO 2 were irradiated with 198 MeV 132Xe ions to the same fluence at temperatures ranging from 25 °C to 700 °C then characterized by synchrotron X-ray diffraction and X-ray absorption spectroscopy. All samples retain crystallinity and their nominal fluorite-type phase at a fluence of 1.5 × 1013 ions/cm2. Both CeO 2 and ThO 2 display defect-induced unit cell expansion after irradiation at room temperature (∼0.15% and ∼0.10%, respectively), yet as irradiation temperature increases, the maximum swelling produced decreases to ∼0.02%. Alternatively, UO 2 shows an initial contraction in unit cell parameter (approximately −0.05%) for room temperature irradiation, most likely related to irradiation-enhanced annealing or irradiation-induced oxidation. At higher temperatures (above 200 °C) UO 2 begins to swell, surpassing its unit cell parameter prior to irradiation (∼0.05%), an effect which could be attributed to minor reduction in uranium oxidation state in vacuum. However, while CeO 2 irradiated at room temperature undergoes partial reduction, both UO 2 and ThO 2 exhibit no measurable change in cation oxidation state as evidenced by X-ray absorption spectroscopy. All samples display a decrease in irradiation-induced heterogeneous microstrain as a function of increasing irradiation temperature. [ABSTRACT FROM AUTHOR]

The effectiveness of membrane-based separations is limited by fouling of the membrane used. In order to mitigate this effect on PET track-etched membranes (PET TeMs), the methods of oxidation in hydrogen peroxide and radiation induced graft polymerization of acrylic acid (AA) and N-vinylimidazole (VIM) were used. The antifouling properties of the modified PET TeMs have been evaluated using model systems, such as water solutions of bovine serum albumin (BSA) and lysozyme (LYZ). The results showed that oxidation led to improved antifouling properties, whereas graft polymerization of AA and VIM on the contrary, led to increased fouling of the membrane surface. [ABSTRACT FROM AUTHOR]

Electrochemical sensors based on PET track-etched membranes (TeMs) were prepared by photograft polymerization of 2-hydroxyethylmethacrylate (HEMA) and subsequent formation of interpolyelectrolyte complexes with poly(allylamine) (PAlAm). The functionalized TeMs were characterized by scanning electron microscopy (SEM), FTIR spectroscopy, gas permeability and colorimetric assay. Parameters of graft polymerization such as monomer concentration, time of irradiation, solvent and others were estimated and optimized. Cd(II) and Pb(II) ions were detected by using square wave anodic stripping voltammetry (SW-ASV). Additional modification of the modified membranes with 4-mercaptophenylboronic acid (MPBA) led to increasing of stability of the sensors. The linear range for the detection of Cd(II) and Pb(II) ions using the modified electrode was 50 µg - 4.25 mg/L and 10 µg – 4.25 mg/L. Moreover, the obtained results of SW-ASV demonstrated that the enhancement in the electrochemical signals was achieved with PET TeMs-g-PHEMA-PAlAm\MPBA compared to that of a bare PET TeMs-g-PHEMA. Selectivity test showed that alkali and alkaline earth metal ions, except for magnesium (up to 1 mg/l), do not particularly interfere with the determination of lead and cadmium in the analyte. Sensing of Pb and Cd ions in river water demonstrate us that prepared sensors can be used in real conditions with sufficient accuracy and reproducibility of the results. [Display omitted] • The modification of membranes by graft polymerization of 2-HEMA. • Formation of interpolyelectrolyte complexes with PAlAm on the membrane surface. • Modification with MPBA led to increase the stability of sensors. • SW-ASV used to for detection of Pb2+ and Cd2+ ions in water. • Modified membranes with interpolyelectrolyte complexes led to improve LOD. [ABSTRACT FROM AUTHOR]

Poly(ethylene terephthalate) PET, track-etched membranes (TeMs) with 400 nm average pore size were UV-grafted with poly(acrylic acid) (PAA) after oxidation of inner surfaces by H 2 O 2 /UV system. Carboxylate groups of grafted PAA chains were easily complexed with Cu 2+ ions in aqueous solutions. These ions were converted into metallic copper nanoparticles (NPs) by radiation-induced reduction of copper ions in aqueous-alcohol solution by gamma rays in the dose range of 46–250 kGy. Copper ions chelating with -COOH groups of PAA chains grafted on PET TeMs form polymer-metal ion complex that prevent the formation of agglomerates during reduction of copper ions to metallic nanoparticles. The detailed analysis by X-Ray diffraction technique (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) confirmed the deposition of copper nanoparticles with the average size of 70 nm on the inner surface of nanochannels of PET TeMs. Samples were also investigated by FTIR, ESR spectroscopies to follow copper ion reduction. [ABSTRACT FROM AUTHOR]

This is a report on the functionalization of track-etched membrane based on poly(ethylene terephthalate) (PET TeMs) by various advanced oxidizing systems/agents (H2O2/vis, H2O2/UV, Fenton/vis, Fenton/UV and O3 treatment) to compare with KMnO4/H2SO4, for the purpose of increasing hydrophilicity and functionality thus expanding potential applications. The surface of functionalized PET TeMs was characterized by using colorimetric assay, contact angle measurements, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), ATR-FTIR-spectroscopy, and Atomic Force Microscopy (AFM). Optimal conditions related to concentration of oxidizing agents and duration of treatment for each oxidation system was determined. Comparative analysis of oxidation systems was made and H2O2/UV and O3 treatment were determined to provide the highest level of hydrophilicity and carboxylic acid functionality on the membranes under relatively milder conditions. [ABSTRACT FROM AUTHOR]