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The nanoindentation test was used to investigate the mechanical properties of borosilicate glass with a composition (mol%) of 40 Na2B4O7-40 SiO2-(20-x) V2O5-x Co2O3, with x = 0, 1, 3, and 5 mol% for samples A, B, C, and D, respectively. Samples were prepared using the melt quenching technique at 1100 °C. A load–displacement curve was plotted and used to extract select mechanical properties of the glass samples. The creep deformation behavior of the glass composition was studied. The maximum creep rate was observed for the sample that contained the highest vanadium oxide content, and the creep rate decreased with a decrease in the vanadium oxide content in the glass samples. The hardness and reduced modulus of elasticity were obtained. The Maxwell–Voigt model was applied to investigate the relaxation kinetics and deformation of the bulk glass.

Borosilicate glass has potential application in the vitrification of high-level waste; therefore, its radiation durability attracts extensive attention. Borosilicate glass samples were irradiated with Xe and Au ions. The samples after irradiation were analyzed by nanoindenter, the Raman, photoluminescence (PL) and infrared spectroscopy. With increase of irradiation dose, the hardness of NBS2 glass samples dropped and then saturated. The changes in PL and infrared spectra of NBS2 glasses samples were deduced. The relation between changes in Raman spectra and those in PL spectra was discussed. The results from PL and infrared spectra revealed the formation of a non-bridging oxygen hole center and transformation of BO4 to BO3 in the NBS2 glass after the irradiation of ions. Relations between the changes in hardness and microstructures of borosilicate glass were discussed. [ABSTRACT FROM AUTHOR]

Seven magnesium‐containing aluminoborosilicate glasses, with three to five oxides, have been studied through comprehensive multinuclear 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‐17 NMR showed the formation of mixing sites containing both Na and Mg near nonbridging oxygen sites. Furthermore, a high magnesium content appears to result in the formation of two subnetworks (boron and silicon rich) with different polymerization degrees as well as to promote the formation of high‐coordination aluminum sites (Al[V] and Al[VI]). Finally, magnesium coordination ranging from 4 to 6, with a mean value shifting from 5 to 6 along the series, suggests that magnesium might endorse an intermediate role in these glasses. [ABSTRACT FROM AUTHOR]

Quantitative Structure Property Relationship (QSPR) analysis based on molecular dynamics (MD) simulations is a promising approach for establishing the composition‐property relationships of glasses and other materials with complex structures. A series of 20 borosilicate, aluminosilicate, and boroaluminosilicate glasses have been modeled using MD simulations with recently developed effective potentials. Short‐ and medium‐range structures of these glasses were analyzed and, based on the structural information, QSPR analysis of the initial dissolution rates (r0) of these glasses that were measured at 90°C and pH 9 by using various structural descriptors such as percentage of bridging oxygen species, network connectivity, and average ring size. The structural descriptor, Fnet, which contains both energetic information such as single bond strength and structural information such as cation coordination number and Qn distribution, was also used. It was found that while the overall network connectivity, average ring size and Fnet provide reasonable correlations with r0 of studied glasses, Fnet gives the best correlation among the descriptors. For glasses that show incongruent dissolution, it was found that modification of glass compositions to account for preferential release of modifier cations is necessary to achieve best correlations. The findings were discussed with results of recent studies on evaluating the compositional dependence of glass dissolution behavior using the topological‐constraints‐based models. [ABSTRACT FROM AUTHOR]

Using electron microscopy and electron probe X-ray fluorescence microanalysis, we have studied chemical and structural changes in the zone of high-temperature contact between 08Cr18Ni10Ti steel and model alkali alkaline earth borosilicate waste form materials for radioactive waste immobilization. The results demonstrate that high-temperature contact with molten waste form materials considerably speeds up corrosion of the metal and that corrosion on the steel surface leads to segregation of corrosion products and the formation of iron chromium spinel and metallic nickel grains under the glass layer. The oxidation product layer has the form of a borosilicate glass-filled porous network. The thickness of this layer depends on the chemical composition of the borosilicate waste form material because the oxidized components of the steel differ in solubility and because the viscosity of the molten waste form material, determining the diffusion rate of the components, varies with composition. [ABSTRACT FROM AUTHOR]

Glass for pharmaceutical packaging requires high chemical durability for the safe storage and distribution of newly developed medicines. In borosilicate pharmaceutical glasses which typically contain a mixture of different modifier ions (alkali or alkaline earth), the dependence of the chemical durability on alkaline earth oxide concentrations is not well understood. Here, we have designed a series of borosilicate glasses with systematic substitutions of CaO with MgO while keeping their total concentrations at 13 mol% and a fixed Na2O concentration of 12.7 mol%. We used these glasses to investigate the influence of R = [MgO]/([MgO] + [CaO]) on the resistance to aqueous corrosion at 80°C for 40 days. It was found that this type of borosilicate glass undergoes both leaching of modifier ions through an ion exchange process and etching of the glass network, leading to dissolution of the glass surface. Based on the concentration analysis of the Si and B species dissolved into the solution phase, the dissolved layer thickness was found to increase from ~100 to ~170 nm as R increases from 0 to 1. The depth profiling analysis of the glasses retrieved from the solution showed that the concentration of modifier ions (Na+, Ca2+, and Mg2+) at the interface between the solution and the corroded glass surface decreased to around 40%–60% of the corresponding bulk concentrations, regardless of R and the leaching of modifier cations resulted in a silica‐rich layer in the surface. The leaching of Ca2+ and Mg2+ ions occurred within ~50 and <25 nm, respectively, from the glass surface and this thickness was not a strong function of R. The leaching of Na+ ions varied monotonically; the thickness of the Na+ depletion layer increased from ~100 nm at R = 0 to ~200 nm at R = 1. Vibrational spectroscopy analysis suggested that the partial depletion of the ions may have caused some degree of the network re‐arrangement or re‐polymerization in the corroded layer. Overall, these results suggested that for the borosilicate glass, replacing [CaO] with [MgO] deteriorates the chemical durability in aqueous solution. [ABSTRACT FROM AUTHOR]

The dissolution rate of some glasses accelerates after prolonged time spent at a slow, residual dissolution rate. This phenomenon is referred to as Stage III behavior. The acceleration in glass dissolution rate linked to Stage III behavior is significant and may be the most impactful behavior to long‐term performance of glass in a repository. This work is aimed at understanding the effect of glass composition on Stage III behavior to add a level of technical defensibility to glass disposal. To this end, a set of 24 glass compositions were statistically designed, where eight glass components (SiO2, B2O3, Al2O3, CaO, Na2O, SnO2, ZrO2, and Others) have been independently varied in order to study the individual effects of each glass component. These glasses have been subjected to static dissolution tests at 90°C in deionized water and then seeded with zeolite Na‐P2 28 days into the testing to induce Stage III behavior. The response of the glasses to the zeolite seeds fell into four primary types: (1) no response to seeds; (2) an immediate linear sustained acceleration in the rate; (3) an immediate linear acceleration in the rate followed by a decrease; and (4) a progressive acceleration in the rate that is concurrent with the addition of the seeds. The main glass components observed to influence these behaviors were CaO, Al2O3, B2O3, and ZrO2, where (1) CaO influenced which glasses showed a Stage III response to seeds (high CaO: types 2, 3, and 4) or did not respond to seeds (low CaO: type 1), (2) Al2O3 and B2O3 influenced which glasses showed a sustainable Stage III response (high Al2O3: types 2 and 4) versus transitory response (low Al2O3 and high B2O3: type 3), and (3) ZrO2 concentration influenced whether glasses showed a linear (high ZrO2: type 2) versus progressive (low ZrO2: type 4) response to seeds. [ABSTRACT FROM AUTHOR]

Glasses are prepared with the oldest accepted technique of melting the silica, boron oxide and alkali oxides with 2% copper oxide and quenching in air. XRD, SEM with EDX, optical methods are employed to study the microstructure of the material. The ductile nature of glass is observed from DTA studies. Glass formation is confirmed by X-ray diffraction spectra. The measured band gaps from both reflectance spectra and absorption spectra are compared and show they are in good agreement. To know the degree of the covalency of bonds, bonding parameters are calculated from EPR data. The Covalency of bonds in host glasses influences the Luminescence emission of Cu2+ ions in the visible region. The molecular structure of glasses is studied using FTIR.The covalent nature of molecular orbitals and molecular structure in the prepared samples is analysed systematically. Also, the various physical properties evaluated concerning the concentration of Alkali ions are reported. The covalent nature of glasses is observed from metallisation criterion. [ABSTRACT FROM AUTHOR]

Thermal strengthening remains the primary method for enhancing the practical strength of commodity glass products, however, the process is limited in terms of applicable glass thickness and coefficient of thermal expansion. The primary reasons for this limitation are the achievable heat transfer coefficient when using conventional gas cooling, and the occurrence of transient surface tension in the early stages of rapid quenching. We revisit this problem for the case of thin borosilicate glass sheet. Using liquid gallium as the cooling medium, ultra‐fast heat extraction is achieved, with a heat transfer coefficient exceeding 5000 Wm−2 K−1. The low vapor pressure of gallium even at high temperatures enables preheating to a wide range of sheet entrant temperatures. We demonstrate thermal strengthening of low‐expansion borosilicate glass with persistent surface compression of up to 85 MPa, and quenching to a fictive temperature of ~190 K above the glass transition temperature. Glass sheet obtained in this way exhibits notably enhanced surface defect resistance to sharp indentation. In addition to thermal strengthening, the extraordinarily high heat extraction rates achieved by liquid metal immersion enable exploitation of high‐Tf glass properties beyond small and thin sample geometry. [ABSTRACT FROM AUTHOR]

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 synthesized and exposed to Au‐irradiation to examine compositional effects on 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 reorganization and changes to the chemical composition of each phase. A general mechanism of coalescence to form larger particles was observed for [MoO3] < 2.5 mol%, whereas segregation to form smaller more evenly distributed particles was seen for [B2O3] ≤ 15 mol% and [MoO3] ≥ 2.5 mol%. 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 ~20 mol%, 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. [ABSTRACT FROM AUTHOR]

The shear behaviors of two multicomponent borosilicate glasses, Borofloat®33 (Boro33) and N‐BK7® (N‐BK7), under different pressures are investigated using molecular dynamics simulations. The addition of alkali ions lowers the yield stress and changes the pressure dependence of shear modulus. Shear‐induced densification is observed in both glasses. It is found that the decreases of the oxygen‐centered bond angle and the coordination number change of B are responsible for the density changes at low pressures, and the increase of 5‐coordinated Si is the dominant mechanism for densification at high pressures. The average shear stresses experienced by Si and B decrease with pressure except that the flow stress of Si at the end of shear deformation in N‐BK7. Moreover, the average shear stress of B is more sensitive to the applied pressures compared to Si, suggesting that B is able to relax mechanical stress more easily under pressurized‐shear. By analyzing the nonaffine displacement of atoms, it is found that N‐BK7 exhibits more localized plastic deformation compared to Boro33 at low pressures and the local rearrangements in both glasses become more homogeneous with increasing pressure. The mean squared nonaffine displacement curves show that alkali ions have the highest mobility induced by shear compared to the network formers and B is more mobile than Si for both glasses. We also observed that plastic deformation tends to take place around boron atoms for Boro33, whereas it occurs in the alkali‐rich regions for N‐BK7, indicating that these two glasses have different atomic‐scale deformation mechanisms. [ABSTRACT FROM AUTHOR]

In this paper, the effect of doping phosphorus in a borosilicate glass matrix to improve the solubility of Mo was investigated by X-ray diffraction (XRD), Raman, and solid-state nuclear magnetic resonance (NMR) spectroscopy, and the effectiveness of Na content on P species inhibiting the growth of the crystallization of Mo was assessed. The results indicate that phosphate-doped borosilicate glass can host 4 mol% of Mo, and that such a borosilicate glass matrix could only accommodate 1 mol% of Mo without phosphate doping. The effectiveness of phosphorus may be correlated with the Na content in borosilicate glass, and a high Na content borosilicate glass matrix requires more P doping to accommodate Mo. In addition, incorporating large amounts of P can compromise the aqueous durability of the glass matrix.

Subsurface damage (SSD) is the fracture and deformation near the surface of brittle optical materials, caused by surface lapping or grinding. The existence of SSD dramatically influences the performance of optical glass and reduces the laser-induced damage threshold. Subsurface cracks of borosilicate glass can be spontaneously healed when heated under appropriate conditions. In this paper, thermal healing experiments of borosilicate glass (BK7) subsurface cracks are conducted on typical cracks induced by an indentation process, and the effects of the Beilby layer, temperature, crack depth, and water vapor pressure are studied. A semi-empirical relation is obtained through the regression of experimental results to describe the variation of subsurface crack length. Finally, a healing experiment is performed on the subsurface damage formed by grinding. The detection results show both the damage density and maximum damage depth have been reduced after heat treatment, demonstrating the effectiveness of the thermal healing method on eliminating glass subsurface damage. [ABSTRACT FROM AUTHOR]

This work compares the performance of optical lenses made of silica glass or borosilicate glass (BK-7) when submitted to high-flux radiation emitted by a xenon arc lamp or provided by a high-concentration solar tower. Each irradiation test lasted for 60 min, with continuous monitoring of the radiation-flux incident on the lenses and the temperature generated in their vicinity. All silica glass lenses showed a good performance with both irradiation sources, xenon arc lamp and natural solar radiation, contrary to what was observed with the lenses made of borosilicate glass which fractured when irradiated with a xenon arc lamp. The negative behavior observed with the borosilicate lenses is attributed to the fact that the radiation spectrum of a xenon arc lamp contains certain wavelengths, in the near ultraviolet (UV) region, that are not present in the natural solar radiation spectrum at sea level. [ABSTRACT FROM AUTHOR]

Borosilicate glass is one of the most possible candidates for the immobilization of high-level radioactive nuclear waste and leaching is the main way that radionuclides inside the vitrification (borosilicate glass form) enter the biosphere. The leaching properties of borosilicate glass by deionized water were investigated using the MCC-1 static leaching method at 90 °C for 28 d. With the static leaching method developed by American Nuclear Waste Material Characterization Center, the leaching behavior and the corresponding micro-structures of the borosilicate glass were investigated, adopting a variety of spectral characterization methods including inductively coupled plasma optical emission spectrometry (ICP-OES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (Raman), and the grazing incident X-ray diffraction (GIXRD). All of the data from FTIR, Raman and GIXRD indicate that, with corrosion in water, the proportion of Si-O-Si structures in glass increases while the B-related structures disappear, and the micro-structures in the layer near the surface are similar to fused silica. After being immersed for 7 d, a corrosion layer and cracks between the corrosion layer and glass base are observed in the surface of samples, which is identified by scanning electron microscope. The formation of the cracks led to a increase in surface area of glass samples. That finally led to an abnormal increase in the leaching rates of Na and Si elements. [ABSTRACT FROM AUTHOR]

Several different ways of measuring the energy resolution for meV‐resolved inelastic X‐ray scattering (IXS) are compared: using scattering from poly(methyl methacrylate), PMMA, using scattering from borosilicate glass (Tempax), and using powder diffraction from aluminium. All of these methods provide a reasonable first approximation to the energy resolution, but, also, in all cases, inelastic contributions appear over some range of energy transfers. Over a range of ±15 meV energy transfer there is good agreement between the measurements of PMMA and Tempax at low temperature, and room‐temperature powder diffraction from aluminium, so we consider this to be a good indication of the true resolution of our ∼1.3 meV spectrometer. The resolution over a wider energy range is self‐consistently determined using the temperature, momentum and sample dependence of the measured response. The inelastic contributions from the PMMA and Tempax, and their dependence on momentum transfer and temperature, are then quantitatively investigated. The resulting data allow us to determine the resolution of our multi‐analyzer array efficiently using a single scan. The importance of this procedure is demonstrated by showing that the results of the analysis of a spectrum from a glass are changed by using the properly deconvolved resolution function. The impact of radiation damage on the scattering from PMMA and Tempax is also discussed. [ABSTRACT FROM AUTHOR]

This work investigates the CO2 laser cutting of 1 mm thin glass sheets under different ambient conditions. Glass sheets are one of the most favourable material for many microfluidic devices, optical applications, automotive parts, etc. Thermal energy coming out from the CO2 laser beam initiated thermal cracks in the glass. A controlled thermal crack can help in cutting of glass sheets accurately. In this work, CO2 laser processing of glass sheets under different ambient conditions has been performed and compared. Experiments were conducted while keeping the glass sheets in open air and under a water layer of 1 mm with different laser parameters such as laser power, cutting speed and number of passes. Output parameters were evaluated using optical microscopy. Number of crack sites and cut quality were compared in open air and under water CO2 laser processing. [ABSTRACT FROM AUTHOR]

Time Differential Perturbed Angular Correlation (TDPAC) has been used to investigate the local structural changes (if any) in Sodium borosilicate (NBS) Glass and Simulated Waste Oxide loaded sodium borosilicate glass (SNBS) used for immobilization of high-level liquid waste at Trombay, Mumbai. The glasses were doped with 181Hf tracer as TDPAC probe and irradiated with varying dose (1–50 MGy) of gamma radiation using 60Co (average γ energy 1.25 MeV) source. Hyperfine interaction parameters (quadrupole interaction frequency, its distribution and asymmetry of electric field gradient) were obtained for irradiated NBS and SNBS glasses from fitting of TDPAC data using DPAC software. The data was compared with the corresponding unirradiated glasses. Results do not show any micro-crystallinity upon irradiation in both the NBS and SNBS glass even at the highest gamma dose of 50 MGy even though small changes were observed in quadrupole interaction frequency at doses beyond 30 MGy. This suggests that the sodium borosilicate glass used for immobilization of high-level waste at Trombay is stable towards gamma radiation at least up to a gamma dose of 50 MGy. [ABSTRACT FROM AUTHOR]

Investigating the irradiation effects on borosilicate glass is of great significance for understanding the long-term evolutions of this substance in radioactive environments. In the present study, the hardness and modulus of conventional and ion-irradiated borosilicate glass were investigated through nanoindentation measurements. The obtained results show that the maximum decrease of the mean hardness after He and Ar ion irradiation was 8.4% and 17.0%, respectively, when the fluence reached 1.1 × 1015. It was found that the hardness reduction had a significant ionic correlation. Meanwhile, it was observed that the mean modulus increased by less than 5.0%, while there was no meaningful ionic correlation. The variation in hardness and modulus were primarily the consequence of nuclear energy deposition. The hardness recovery was observed under Ar-irradiated and He-irradiated Ar pre-damaged samples. It was concluded that the hardness recovery mainly originates from electronic energy deposition induced by ion irradiation. [ABSTRACT FROM AUTHOR]

New synthesized borosilicate glass system within the molar percentages 50 B2O3 - (14-X) SiO2 - (20+X) Li2O-15 Na2O-1Al2O3 with X=0, 1, 2, 3, 4, 5 mol % was investigated. The amorphous identity of the samples has been checked by X-ray diffraction (XRD). The decrease of the molar volume (Vm) with increasing Li2O amount led to an increase in the calculated oxygen packing density (O.P.D). The packing density of the specimens increased also with the inclusion of Li2O. The Fourier transform infrared (FTIR) showed the transformation of BO3 to BO4 units that increased the rigidity of the prepared glass series. The ultrasound wave velocities (longitudinal (vl) and shear (vs)) were assigned by the pulse-echo technique. Both (vl ) and ( ps ) increased with increasing Li2O content because of increasing the rigidity of the glass host. The elastic Longitudinal (L), Young's (E), Bulk (B) and Shear (S) moduli besides the Micro-hardness (H) were calculated and all increased with increasing Li2O content. Ultrasonic mean velocity (vmean) and softening temperature (Tsm) increased while Poisson's ratio (σm) decreased with the same gradient of X. The theoretical model proposed by (Makishima-Mackenzie) and bond compression model were employed for the prepared glasses. The results from both models showed correspondence with the experimentally obtained values. The impedance spectroscopy was applied to investigate the electrochemical mode of the present glass system and to measure the conductance for all the system samples. [ABSTRACT FROM AUTHOR]

The silicon carbide whose surface had been modified by laser cladding silicon layer was soldered by borosilicate glass. And the borosilicate glass solder had a thermal expansion coefficient similar to that of the silicon carbide substrate. The laser cladding silicon layer significantly improved the wettability between molten glass solder and silicon carbide and could reduce the soldering temperature. A sandwich-like joining structure (SiC/Si/solder/Si/SiC) was made after the borosilicate glass slurry put on the laser cladding silicon layers. The microstructure, compositions, and interfacial properties were studied. Results showed that good adhesion between silicon carbide and the glass soldering layer was achieved. The flexural strength of the connection structure prepared at 900 °C in the air reached 110 MPa. This research provides an effective technical solution for realizing local heat treatment soldering of large silicon carbide components. [ABSTRACT FROM AUTHOR]

• Low content of α-Fe 2 O 3 particles, spanning a particle size range from nanometers to microns, were employed in reactions with sodium borosilicate glass. • Through experimental characterization and numerical simulation, we analyzed the effect of iron oxide particle size on the color of dispersion systems. • Compared to the batch only, less distortion happened by using the melted cullet. Smaller particle sizes of iron oxide doping at 1100 ℃ could retain the structure stability. • We systematically introduced a constitutive model of the reactive process. Fe3+ is readily reacted with structural units to modify various properties of the borosilicate glasses and glass ceramics. However, there exists some controversies on Fe 2 O 3 containing borosilicate glasses: (1) whether the Fe 2 O 3 turned into the nanometer-sized polycrystalline structure or reacted with the glass matrix to form a new substance and (2) whether the role of Fe 2 O 3 was depended on its concentration in the network of glass. Theoretical extinction spectra of α-Fe 2 O 3 particles ranging from 1 to 180 nm in borosilicate glass align with UV–vis absorption spectra. Based on the Na 2 O-B 2 O 3 -Fe 2 O 3 phase diagram , x Fe 2 O 3 ·(100- x) [41.6B 2 O 3 –20.7Na 2 O-19.2CaO-9.7Al 2 O 3 –7.0SiO 2 –0.6ZnO] (x =1.20∼1.95 mol%) were prepared for this study, analyzing from exterior characteristics to interior structure. Molecular vibrational spectroscopy and component structure measurement were applied to study the effect of doping α-Fe 2 O 3 powders (particle sizes of 30 nm, 1 μm, 75 μm) on the sodium borosilicate glasses. Combination of experimental characterization and numerical simulation were also utilized to investigate the effects of iron oxide particle size on the color of dispersion systems. We discovered that (i) doping with either nanometer-sized or micron-sized particles of α-Fe 2 O 3 can result in both the substitution for B3+ in tetra-coordination [BO 4 ] and the bonding with [BO 3 ] units within the amorphous network of sodium borosilicate glasses; (ii) Even at lower concentrations, α-Fe 2 O 3 can still act as a network intermediate, combining both its former role and modifying properties. Based on these outcomes, for the reactive process, we formulated a constitutive model which offers valuable insights into understanding the behavior of iron oxide in sodium borosilicate glass. These findings are crucial for comprehending the processes involved in matrix preparation and are pivotal for progressing to the subsequent stage where designing and fabricating nanocomposite materials based on these matrices with spatial separation. [Display omitted] [ABSTRACT FROM AUTHOR]

Glass coating is an important thermal insulation technique used in the aerospace industry that serves as a thermal protection system (TPS) to protect the inner layer at elevated temperatures. This work highlights the superb mechanical and thermal properties of the B 2 O 3 -SiO 2 glass systems as a surface coating for space shuttle. In the B 2 O 3 -SiO 2 system, the glass transition temperature raises from 650 °C to 750 °C with increasing SiO 2 content and devitrification of the α-cristobalite phase. The Al 2 O 3 addition in B 2 O 3 -SiO 2 glass can increase the glass transition temperature from 750 °C to 1000 °C and inhibit the α-cristobalite phase. The phase transition from an unstable α-cristobalite phase to an amorphous phase was achieved at 10 wt% Al 2 O 3 -added specimens. This study demonstrates that the Al 2 O 3 -B 2 O 3 -SiO 2 glass (ABS glass) exhibits thermally stable behavior, making it an effective thermal barrier coating at elevated temperatures. [ABSTRACT FROM AUTHOR]

• The refining process of alkali borosilicate glass with CeO 2 as refining agent was continuously recorded and analyzed. • The addition of CeO 2 led to the increase of viscosity of the glass melts. • The depolymerization increased with CeO 2 , deteriorating the water resistance of the glass. CeO 2 has been used as the refining agent in the melting of borosilicate glasses. The study of its influence on glass melt, structure and properties is inadequate. In this work, a series of borosilicate glasses were prepared with batches containing 0∼0.6wt% of CeO 2. Besides the in-situ observation of refining process, the structure of the glasses was systematically investigated via IR, Raman,11B and 29Si NMR spectroscopy. The results showed that the viscosity of melts increased with CeO 2 due to aggregation effect of Ce ions. However, the release of oxygen was dominant at high-temperature, thus the melt prepared with 0.6wt% CeO 2 had the fastest refining rate, and was bubble-free within 60 min at 1550℃. With the increase of CeO 2 , both Q3 species and [BO 3 ] in the glass network increased in the final sample, indicating the structure depolymerization, which led to the decrease of the chemical stability. [ABSTRACT FROM AUTHOR]

Rare-earth (RE) doping is one of the valid approaches to optimize the optical performance of the CsPbBr 3 perovskite quantum dot glass. Thus, the research on the crystallization behavior of RE ions doped CsPbBr 3 borosilicate glass and the energy transformation mechanism between the RE ions and CsPbBr 3 is significant for the development of advanced Ln-doped perovskite glass materials. In this work, CsPbBr 3 borosilicate glass ceramics doped with different concentrations of Nd 2 O 3 were successfully synthesized. It was found that Nd 2 O 3 makes the glass network structure more compact and then inhibits the precipitation of CsPbBr 3 nanocrystals. Additionally, there is energy transfer between Nd3+ and CsPbBr 3 , which quenches the photoluminescence of CsPbBr 3 borosilicate glass. This work deepens the understanding of the structural and photophysical properties of Ln-doped CsPbBr 3 borosilicate glass ceramics and provides a reference value for the related work of RE ions doped perovskite borosilicate glass. • Strengthened glass network and quantum confinement effect appear after the addition of Nd 2 O 3. • Suppressing Br− vacancies in CsPbBr 3 via interstitial doping with multivalent cations. • The fluorescence resonance energy transfer occurs between Nd3+ and CsPbBr 3. [ABSTRACT FROM AUTHOR]

Materials, promising for production of luminescent solar energy concentrators were considered. It is known that the silicon oxide matrix is transparent within the spectral range where Sun emits light. Up to date, the low-temperature sol-gel method for synthesizing SiO2 coatings with the simultaneous doping of the material with quantum dots (QDs) is developed. The transmission spectrum of borosilicate glasses (BK7) is narrower than that of SiO2. Typically, the doping of BK7 with the quantum dots of the group AIIBVI is carried out using the method of condensation at high temperatures, which results in a low value of the quantum yield of luminescence. Minimal losses of luminescent quanta through the leakage cone will be in the matrix of glass LASF35 022291.541, which refractive index is 2.02204. In the research of the properties of photoconductors with a luminescent concentrator, the matrix is most often made of polymethylmethacrylate (PMMA). Its doping with QDs and dyes is well developed. The quantum yield of luminescence of luminophores when doping PMMA with dyes and QDs is close to unity. The magnitude of losses of luminescent quanta in matrices of glass, PMMA and silica has been estimated. Dependence of these losses on the wavelength, which should be taken into account in the study of stacked fluorescent concentrators, has been analyzed.

Particle deposition on the surface of a drying chamber is the main drawback in the spray drying process, reducing product recovery and affecting the quality of the product. In view of this, the potential application of chemical surface modification to produce a hydrophobic surface that reduces the powder adhesion (biofouling) on the wall of the drying chamber is investigated in this study. A hydrophobic polydimethylsiloxane (PDMS) solution was used in the vertical dipping method at room temperature to determine the optimum coating parameters on borosilicate glass and stainless steel substrates, which were used to mimic the wall surface of the drying chamber, to achieve highly hydrophobic surfaces. A single-factor experiment was used to define the range of the PDMS concentration and treatment duration using the Response Surface Methodology (RSM). The Central Composite Rotatable Design (CCRD) was used to study the effects of the concentration of the PDMS solution (X1, %) and the treatment duration (X2, h) on the contact angle of the substrates (°), which reflected the hydrophobicity of the surface. A three-dimensional response surface was constructed to examine the influence of the PDMS concentration and treatment duration on contact angle readings, which serve as an indicator of the surface’s hydrophobic characteristics. Based on the optimisation study, the PDMS coating for the borosilicate glass achieved an optimum contact angle of 99.33° through the combination of a PDMS concentration of X1 = 1% (w/v) and treatment time of X2 = 4.94 h, while the PDMS coating for the stainless steel substrate achieved an optimum contact angle of 98.31° with a PDMS concentration of X1 = 1% (w/v) and treatment time of X2 = 1 h. Additionally, the infrared spectra identified several new peaks that appeared on the PDMS-treated surfaces, which represented the presence of Si-O-Si, Si-CH3, CH2, and CH3 functional groups for the substrates coated with PDMS. Furthermore, the surface morphology analysis using the Field Emission Scanning Electron Microscopy (FESEM) showed the presence of significant roughness and a uniform nanostructure on the surface of the PDMS-treated substrates, which indicates the reduction in wettability and the potential effect of unwanted biofouling on the spray drying chamber. The application of PDMS and PTFE on the optimally coated substrates successfully reduced the amount of full cream milk particles that adhered to the surface. The low surface energy of the treated surface (19–27 mJ/m2) and the slightly higher surface tension of the full cream milk (54–59 mJ/m2) resulted in a high contact angle (102–103°) and reduced the adhesion work on the treated substrates (41–46 mJ/m2) as compared to the native substrates.

To achieve effective antioxidation of on-site repair coating for C/C brake materials in the full temperature range (500–900 °C), lead glass and bismuth glass were introduced into the borosilicate glass to acquire the protective coatings. Before preparing coating samples, the thermal gravity characteristics of the lead/bismuth–borosilicate glass powders were analyzed by TG/DSC. The results revealed that the temperature at which weight gain begins was 495 °C and 545 °C, respectively. The oxidation behaviors of the lead- and bismuth-modified borosilicate glass coatings were compared at 500 °C, and the antioxidation properties of the former were further examined from 500 to 900 °C. The oxidation results indicated that mixing lead glass with borosilicate glass realized effective oxidation resistance in the full temperature range. With a lead content of 20%, the lead–borosilicate glass coating was able to protect C/C substrates from oxidation. The corresponding weight loss of the lead-glass-coated samples was −1.89% when oxidized at 500 °C for 10 h, while the weight loss was −2.55% when further oxidized at 900 °C for 10 h. However, mixing bismuth glass with borosilicate glass was difficult to achieve the oxidation resistance of the coating at 500 °C due to the significant phase separation.

In the study we presented the types of solutions for each type of nuclear wastes which have been analyzed, as well as the procedures for their implementation. The superiority of the waste immobilizing matrices (waste forms) are outlined mostly in this paper, stating the pros and cons of different types of waste forms as making an analysis of the spent fuel and the production methods. The waste majority of the nuclear waste is immobilized with borosilicate glass, on which we made a broader analysis, as well as providing solutions for the wastes difficult to incorporate in borosilicate. Fr this type of waste a ceramic or glass solution is preferred, because of its economical benefits. It was also presented the final deposit disposal configuration, and a comparative analysis between surface disposal and deep geological disposal of the nuclear waste. Finally, several suggestions for future research in this area have been provided.

An islet-on-chip system in the form of a completely transparent microscope slide optically accessible from both sides was developed. It is made from laser-structured borosilicate glass and enables the parallel perifusion of five microchannels, each containing one islet precisely immobilized in a pyramidal well. The islets can be in inserted via separate loading windows above each pyramidal well. This design enables a gentle, fast and targeted insertion of the islets and a reliable retention in the well while at the same time permitting a sufficiently fast exchange of the media. In addition to the measurement of the hormone content in the fractionated efflux, parallel live cell imaging of the islet is possible. By programmable movement of the microscopic stage imaging of five wells can be performed. The current chip design ensures sufficient time resolution to characterize typical parameters of stimulus-secretion coupling. This was demonstrated by measuring the reaction of the islets to stimulation by glucose and potassium depolarization. After the perifusion experiment islets can be removed for further analysis. The live-dead assay of the removed islets confirmed that the process of insertion and removal was not detrimental to islet structure and viability. In conclusion, the present islet-on-chip design permits the practical implementation of parallel perifusion experiments on a single and easy to load glass slide. For each immobilized islet the correlation between secretion, signal transduction and morphology is possible. The slide concept allows the scale-up to even higher degrees of parallelization.

The paper discusses the current status of the HLW vitrification technology applied at the radiochemical plant of the Mayak PA. Conceptual and technical solutions proposed to develop the technology of vitrification of various types of liquid HLW at the Mayak PA are presented. Compositions of borosilicate glasses with HLW components are described, temperatures of their melting and easy pouring are determined. Chemical durability parameters obtained for the borosilicate glasses are provided.