Search

Thermoluminescence glow curves of gamma-irradiated Samarium doped lithium borosilicate glass were investigated. The number of overlapping peaks is determined using the Repeated Initial Rise (RIR) method. The glow curves were deconvoluted into four overlapping peaks. The trapping parameters such as activation energy E, frequency factor (s), and kinetic order (b) for each peak are determined. The obtained results indicated that the Lithium borosilicate glass doped with Samarium has four electron trap levels with the average activation energies of 0.82,1.01,1.21, and 1.31eV, respectively. Thermal fading analysis of the individual peaks based on the deconvolution data is performed. The obtained results showed high thermal fading of the first peak while high thermal stability of the second and third peaks compared with the other peaks. These results could be used to explain some observed properties such as high thermal fading and light sensitivity for such thermoluminescence material. Moreover, the obtained results may be helpful to minimize the fading corrections in the dosimetric applications.

Although glass recycling is considered to be a default method for glass waste management, fine fractions of container soda-lime glass, or cullet of other compositions are still landfilled. This happens despite existing alternatives. Success could lie in advanced upcycled products that bring higher economic motivation for the implementation in industry, but these are often connected to alternative ways of product synthesis. We provide an example of waste glass upcycling by the preparation of glass microspheres (GM) from specialty low-sodium alumino borosilicate-based glasses via flame synthesis (FS). GM and the precursors, either from colorless medical vials or glass fibers, were characterized by scanning electron microscopy (SEM), simultaneous thermal analysis coupled with differential thermal analysis (STA-DTA), and image analysis. A dynamic corrosion test was performed and evaluated via ion-coupled plasma with optical emission spectroscopy (ICP-OES) to observe corrosion kinetics products. FS has proved to be a fast method of waste glass processing into GM. This article, besides the characterization of the starting material and final products, also suggests the possibility of processing for other landfilled waste glasses and also discusses the manufacturing of GM for water filters and fillers for polymers.

A series of Dy3+ /Sm3+ /Er3+ triply doped multicomponent borosilicate glasses (DSE) was synthesized using varying Er3+ ions concentrations through a conventional melt quenching technique. The influence of triple doping on the optical characteristics of the prepared glass was evaluated to estimate the possibility of achieving white light emission through optical absorption, photoluminescence excitation (PLE), and emission (PL) measurements. Based on the PLE and PL spectral profiles, the presence of energy transfer processes between Dy3+ , Sm3+ , and Er3+ was confirmed. Furthermore, for Dy3+ /Sm3+ /Er3+ triply doped glass, an enhancement in Er3+ green luminescence and a noticeable decrease in Dy3+ and Sm3+ emissions were detected with the increase in Er3+ concentration. The nature of energy transfer in DSE glass was investigated through Dexter's energy transfer mechanisms and the obtained result suggested that a dipole-dipole interaction was responsible for the dominant Sm3+ to Dy3+ and Dy3+ to Er3+ energy transfer processes. The precise characteristic colours that emanated from the as-prepared samples were evaluated using Commission Internationale de l'Eclairage co-ordinates and correlated colour temperature values and suggested its suitability for white light emission. The quantum efficiency of the prepared glass was determined experimentally. The aforementioned results recommend that the Dy3+ /Sm3+ /Er3+ triply doped multicomponent borosilicate glass irradiated with ultraviolet light sources might be useful for the generation of cool/warm white light-emitting applications.

International audience; Seven magnesium-containing aluminoborosilicate glasses, with three to five oxides, have been studied through comprehensive multi-nuclear solid-state NMR (11B, 27Al, 29Si, 23Na, 17O and 25Mg) and Raman spectroscopy. The progressive addition of cations and the substitution of sodium and calcium by magnesium illuminate the impact of magnesium on the glass structure. The proportion of tri-coordinated boron drastically increased with magnesium addition, demonstrating the poor charge-compensating capabilities of magnesium in tetrahedral boron units. Oxygen-17NMR showed the formation of mixing sites containing both Na and Mg near non-bridging oxygen sites. Furthermore, a high magnesium content appears to result in the formation of two sub-networks (boron and silicon rich) with different polymerization degrees as well as to promote the formation of high-coordination aluminium sites (Al[V] and Al[VI]). Finally, magnesium coordination ranging from four to six, with a mean value shifting from five to six along the series, suggests that magnesium might endorse an intermediate role in these glasses.

International audience; We evaluated the feasibility of inferring the bubble volume fraction (b) in a melt by employing in situ impedance spectroscopy measurements. This idea stems from the effective medium theory, in which the ionic conductivity of a biphasic material can be determined from the isolated contribution of each constituent phase and their respective volumetric content. Therefore, we investigated the overall electrical conductivity of a borosilicate melt doped with cerium-IV oxide at a constant temperature (1273 K), in which O2 gas production takes place. To validate the use of this proposed technique, post-mortem bubble volume fraction analyses on samples synthesized following the same procedure were conducted by apparent density and impedance spectroscopy measurements at low temperatures (below Tg). A comparison of these post-mortem and in situ techniques is presented. Despite some discrepancies observed between the bubble volume fractions estimated by these different methods, the main results demonstrate the technical viability of this in situ approach. In situ impedance spectroscopy presents advantages in terms of presynthesis duration, sample preparation, and the information is obtained at high temperatures, eliminating the possible influence of the cooling stage.

International audience; The temperature dependence of glass relaxation has been intensively studied; however, the effect of an imposed pressure history on relaxation behavior is poorly understood. In this study, we subjected SCHOTT N-BK7® borosilicate glasses to isostatic compression in a Paterson press (PP) and a gas pressure chamber (GPC). The pressure ranged from 0.1 GPa to 2 GPa for various dwell temperatures and times near the glass transition region. Comparison with our recent results on the same glass using the piston-cylinder apparatus (PC, 0.5-1.5 GPa) reveals that the density of a glass, which has been quenched from the equilibrium state under high pressure at 2 K/min (pressure quench), increases approximately linearly with increasing pressure up to 2 GPa. Considering the volume recovery results at ambient pressure, we assert that the preceding high-pressure treatment in PC (uniaxial loading) generates a similar isostatic pressure effect on N-BK7 glass as those of PP and GPC treatments. Finally, we verify the previously proposed two-internal-parameter relaxation model on the volume recovery data using the three different compression methods. With a new set of parameters in the model, we can account for the pressure and temperature dependence of volume relaxation even for the samples quenched from nonequilibrium states at high pressure.

Lithium borosilicate glass composite (SiO2 -Li2 CO3 -H3 BO3 ) doped with various concentrations of Sm2 O3 (0-0.7 mole %) was prepared using the melt quenching method. The investigated thermoluminescence (TL) characteristics of the prepared system revealed that the highest TL response was obtained for this glass composite at 0.05 mol% Sm2 O3 . In this study, the 0.05 mol% Sm2 O3 -doped lithium borosilicate glass composite was subjected to detailed dosimetric investigation in terms of its annealing condition, dose-response, and minimum detectable dose. The reproducibility of the response, thermal characteristics, and optical fading were also studied. The obtained results showed that the prepared glass composite had a linear dose-response over the wide gamma dose range 2Gy to 2 kGy, as well as reasonable thermal fading and excellent reproducibility. These attributes render the composite under investigation promising for utilization in radiation detection.

The preparation of single‐phase and catalytically active GaPd2 coatings was accomplished via DC magnetron sputtering using an intermetallic sputter target. Thin and uniform layers were deposited on borosilicate glass, Si(111) and planar as well as micro‐structured stainless steel foils. The specimens were examined regarding their phase composition, film morphology and microstructure. Thin films of different layer thickness were catalytically characterized in the semi‐hydrogenation of acetylene, which was conducted at 473 K and a feed gas composition of 0.5 vol.% C2H2, 5 vol.% H2 as well as 50 vol.% C2H4 in helium. Pre‐reduction of the catalyst was found to be essential to enhance the catalytic selectivity. Sputtered GaPd2 showed a high selectivity of 73 % for the hydrogenation to ethylene at conversion levels above 80 %. The surface‐specific activity was strongly increased to 8.97 molacetylene· (A 0· h)–1 compared to bulk‐ or nanoscale GaPd2 (1.93 and 0.30 molacetylene· (A 0· h)–1, respectively) caused by the high specific surface area of the thin films.

From a large ensemble of 34 silicate-based glasses from the borosilicate, phosphosilicate, and borophosphosilicate systems that comprise either Na as a sole glass-network modifier or when mixed wit ...

Three kinds of borosilicate glass-ceramics Low temperature co-fired ceramics (LTCC) substrate materials, Ca-B-Si-O (CBS), Ca-Al-B-Si-O (CABS), and Ca-Mg-B-Si-O (CMBS), have been prepared, and the biocompatibility of these materials was evaluated. Compared with CBS and CMBS samples, the CABS sample presented the lowest crystallinity and dissolution in the bioleaching experiments. The direct and indirect cell culturing results showed that the CABS sample also possessed the best biocompatibility to the bone mesenchymal stem cells (BMSCs) due to its good bio-stability and surface micro-pore structure. The effects of surface topography and released ions on cytocompatibility were analyzed. These results were expected to offer some guideline information for developing LTCC substrate materials used in the microfluidic biosensors for the future biological and medical application.

The degradation of anti-inflammatory and antipyretic drug (Ibuprofen; IBP) has been described in this study by using photocatalytic-based advanced oxidation processes. The catalysts (TiO2 and ZnO) were activated by irradiation of artificial UV lamp and solar rays for the generation of highly oxidizing species which resulted in the degradation of IBP to intermediates and finally to carbon dioxide and water. In solar reactor, quartz and borosilicate tubes were installed for absorption of required ultraviolet rays and curved chrome plates were used to reflect and concentrate rays on the tubes containing feed mixture. The liquid chromatography, Total organic carbon (TOC), and Chemical oxygen demand (COD) tests were employed to determine the degradation rates and demineralization of solution samples. At catalyst dosing of 1-1.5 g/L, TiO2 -based experiments showed high degradation rate under acidic conditions. Similarly, for ZnO catalyst, 1 g/L dozing rate was found to be effective under neutral conditions (pH = 7.0). UV lamp-based photocatalysis had higher degradation rate as compared to that of solar reactor. Moreover, better absorption of solar rays by quartz tubes resulted in higher degradation than that in borosilicate tubes. For UV lamp photocatalysis, the TOC and COD reduction was higher. With improved catalyst doping and better solar reactor design, solar-based IBP degradation could be more promising than UV-based catalysis. PRACTITIONER POINTS: TiO2 and ZnO were employed to generate oxidizing agents for comparative photocatalytic degradation. Degradation rate of Ibuprofen with TiO2 was much higher compared to ZnO. Quartz material was found more effective as radiation absorbing material than borosilicate glass for solar photo catalysis. Influence of catalyst loading (TiO2 and ZnO) and pH conditions on degradation rate and mineralization of IBP was examined. IBP is a carcinogenic and endocrine disrupting drug so its degradation in water can protect ecological and human life.

International audience; A glass‐ceramic waste form is being developed for immobilization of waste streams of alkali (A), alkaline‐earth (AE), rare earth (RE), and transition metals generated by transuranic extraction for reprocessing of used nuclear fuel. Benefits over an alkali borosilicate waste form are realized by the partitioning of the fission product fraction insoluble in glass into a suite of chemically durable crystalline phases through controlled cooling, including (AE,A,RE)MoO4 (powellite) and (RE,A,AE)10Si6O26 (oxyapatite). In this study, a simplified 8‐oxide system (SiO2‐Nd2O3‐CaO‐Na2O‐B2O3‐Al2O3‐MoO3‐ZrO2) was melted, then soaked at various temperatures from 1450 to 1150°C, and subsequently quenched, in order to obtain snapshots into the phase distribution at these temperatures. For these samples, small angle X‐ray and neutron scattering, quantitative X‐ray diffraction, electron microscopy, 23Na nuclear magnetic resonance, Nd3+ visible absorption, and temperature‐dependent viscosity were characterized. In this composition, soak temperatures of urn:x-wiley:00027820:media:jace16406:jace16406-math-00011250°C were necessary to nucleate calcium molybdate (~10‐20 nm in diameter). Further cooling produced oxyapatite and total crystallization increased with lower soak temperatures. Both Na and Nd entered the crystalline phases with lower‐temperature soak conditions. Slow cooling or long isothermal treatments at ~975°C produced significantly higher crystal fractions.

The aim of this paper was to assess factors affecting primary and secondary phase separation in simplified calcium borosilicate glasses studied for nuclear waste applications. Several glasses with varying [MoO3] and [B2O3] were synthesised and exposed to Au-irradiation to examine compositional effects on the glass structure and domain size of separated phases induced by accumulated radiation damage resulting from α-decay over a ~1000 year timeframe. The produced glasses fell within the immiscibility dome of CaO−SiO2−B2O3 and showed a unique microstructure of embedded immiscibility with three identifiable amorphous phases according to electron microscopy, Raman spectroscopy and diffraction. These glasses were then bombarded with 7 MeV Au3+ ions to a dose of 3×1014 ions/cm2 creating an estimated ~1 dpa of damage. Several changes to the morphology, spatial distribution and size of secondary phases were observed, indicative of significant structural reorganisation and changes to the chemical composition of each phase. A general mechanism of coalescence to form larger particles was observed for [MoO3] < 2.5mol%, while segregation to form smaller more evenly distributed particles was seen for [B2O3] ≤ 15mol% and [MoO3] ≥ 2.5mol%. These microscopic changes were concurrent to surface-bulk diffusion of Ca and/or Mo ions, where the direction of diffusion was dependent on [B2O3] with a barrier identified at ~20mol%, as well as cross phase diffusion of said ions. These modifications occurred in part through the formation of distorted ring structures within the borosilicate network, which enabled the increased dissolution of isolated (MoO4)2- units. Au-irradiation was therefore able to increase the solubility of molybdenum and alter the structure and composition of secondary phases with the extent of modification varying with [MoO3] and [B2O3]/[SiO2], though glasses notably remained heterogeneous. The collective results suggest that radiation and composition can both be used as design tools to modulate the domain size and distribution of separated phases in heterogeneous glasses.

Adsorption, sample preservation, and cross‐contamination are the major impediments to the accurate and sensitive analysis of low‐level mercury samples. Common measures to deal with this issue are to use Teflon, quartz, or borosilicate glass bottles for sampling, standard solution and sample preservation with oxidative chemicals, to prepare standard solutions daily and to use dedicated glassware. This paper demonstrates that these measures are neither efficient nor effective. Two common laboratory sample containers (borosilicate volumetric glass flasks and polypropylene tubes) are investigated for the preparation and preservation of water samples and standard solutions of 0.2–1 µg L−1 with 2% HNO3. Mercury adsorption rates of 6–22% are observed within 30 min and after 48 days, the adsorption is greater than 98%. In stark contrast, no adsorption is found during a testing period of 560 days when the solutions are subject to potassium permanganate‐persulfate digestion. New glass flasks and polypropylene bottles are free of mercury contamination but reused flasks are a major source of mercury cross‐contamination. To minimize adsorption and cross‐contamination, standard solutions are treated by potassium permanganate‐persulfate or BrCl digestion, and each individual sample and standard solution should be stored and prepared in single‐use polypropylene bottle, without transference., Adsorption and cross‐contamination are the major challenges for accurate analysis of trace mercury. This study demonstrates that adsorption is the root cause for cross‐contamination, and single use of polypropylene plastic bottles for sample preparation and storage is highly efficient to completely solve these notorious problems as long as sample and standard solutions are subject to potassium permanganate‐persulfate digestion.

The repair and regeneration of loaded segmental bone defects is a challenge for both materials and biomedical science communities. Our recent work demonstrated the capability of bioactive glass in supporting bone healing and defect bridging using a rabbit femur segmental defect model without growth factors or bone marrow stromal cells (BMSCs). Here in the current work, a comprehensive in vitro evaluation of bioactive silicate (13-93) and borosilicate (2B6Sr) glass scaffolds was conducted to provide further understanding of their biological performances and to establish a correlation between in vitro and in vivo behaviors. Our in vitro evaluation using a murine MC3T3-E1 cell line confirmed the capability of both scaffolds to support cell attachment, vascular endothelial growth factor (VEGF) formation, and to stimulate mineral deposition and osteoblast marker gene expression. In particular, borosilicate (2B6Sr) glass showed a better capability in supporting the mineralization and gene expression than silicate (13-93) glass, consistent with a faster bone healing ability in vivo. The current in vitro results, combined with our previous in vivo findings, provide a strong basis for the further translational evaluation of bioactive glass scaffolds and for potential preclinical practice. © 2018 Wiley Periodicals, Inc. J. Biomed. Mater. Res. Part B, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 818-824, 2019.

For the built environment and for engineers, glass is an indispensable material with unique properties. Recent developments have shown that there is a potential market for additive manufacturing technology in the building industry, based on the production with a relatively small amount of repetitions and the tendency of applying technological innovations for advanced buildings. This paper focusses on the potential of fusing glass filaments on a glass base plate in order to develop a scientific base to create a process that is able to print 3D glass on glass plates for applications in the building industry. These fused components could eliminate boreholes for joints in glass panes including related disadvantages. Also, the fused deposition glass components can be a potential reinforcement of flat glass. Therefore, the fusing of soda lime silicate glass and borosilicate glass has been investigated. Based on these experiences, samples with different glass thicknesses are manufactured and the fused components are tested for their bending strength. The manufactured samples are analysed with polarized images, 3D computer tomography, microscopy and energy dispersive X‐ray spectroscopy. This paper describes, presents and discusses the results of the investigations, and demonstrates that load transfer via fused glass joints is possible in principle.

We measured the extensional‐mode attenuation and Young's modulus in a porous sample made of sintered borosilicate glass at microseismic to seismic frequencies (0.05–50 Hz) using the forced oscillation method. Partial saturation was achieved by water imbibition, varying the water saturation from an initial dry state up to ∼99%, and by gas exsolution from an initially fully water‐saturated state down to ∼99%. During forced oscillations of the sample effective stresses up to 10 MPa were applied. We observe frequency‐dependent attenuation, with a peak at 1–5 Hz, for ∼99% water saturation achieved both by imbibition and by gas exsolution. The magnitude of this attenuation peak is consistently reduced with increasing fluid pressure and is largely insensitive to changes in effective stress. Similar observations have recently been attributed to wave‐induced gas exsolution–dissolution. At full water saturation, the left‐hand side of an attenuation curve, with a peak beyond the highest measured frequency, is observed at 3 MPa effective stress, while at 10 MPa effective stress the measured attenuation is negligible. This observation is consistent with wave‐induced fluid flow associated with mesoscopic compressibility contrasts in the sample's frame. These variations in compressibility could be due to fractures and/or compaction bands that formed between separate sets of forced‐oscillation experiments in response to the applied stresses. The agreement of the measured frequency‐dependent attenuation and Young's modulus with the Kramers–Kronig relations and additional data analyses indicate the good quality of the measurements. Our observations point to the complex interplay between structural and fluid heterogeneities on the measured seismic attenuation and they illustrate how these heterogeneities can facilitate the dominance of one attenuation mechanism over another.