Soda-lime Borosilicate Glass Research Articles

Use of Eggshell Waste as a source of CaO in Sm3+-Doped Na2O-B2O3-CaO-SiO2 Glass Preparation

In this research, calcium carbonate from eggshell waste was used to prepare the soda-lime borosilicate glass samples (Na2O-B2O3-CaO-SiO2) doped with samarium ions (Sm3+) at different Sm2O3 concentrations (0, 0.1, 0.2, 0.3, 0.4 and 0.5 mol%). A conventional melt-quenching method at 1,100°C for 3 h was applied in this work to produce the glass samples. The samples were then characterized by XRD, DTA, FT-IR, UV-Vis spectrophotometer and PL techniques. The results showed that the obtained glasses had amorphous structure, and the glass density tended to increase with the addition of Sm2O3. The FTIR spectra of the main glass structure revealed that it was composed of trigonal BO3 and tetrahedral BO4 borate groups mixing with SiO4 tetrahedra and non-bridging oxygen. The addition of samarium ions to the glass resulted in a strong orange emission at 562 nm (4G5/2→6H5/2), 600 nm (4G5/2→6H7/2), 646 nm (4G5/2→6H9/2) and 708 nm (4G5/2→6H11/2) under excitation at 403 nm. The results confirmed that 0.3 mol% Sm2O3-doped glass exhibited the highest emission intensity, which suggested that eggshells have a high potential to be used as an alternative CaCO3-raw material in the production of an efficient luminescent and environmentally-friendly optical electronics material

In vitro studies of B2O3–SiO2–Na2O–CaO–ZnO bioactive glass system

The main purpose of the present investigation is to examine in detail in vitro studies like bioactivity and cytocompatibility of a novel bioactive glass system i.e., B2O3–SiO2–Na2O–CaO–ZnO glass composition. Glasses are prepared by the traditional melt quenching method. In vitro studies are performed with ISO standards. Bioactivity has been studied using standard Kokubo's method. Highly sophisticated analytical techniques were utilized for the assessment of apatite forming ability. Scanning electron microscopy micrographs have shown visible evidence of apatite forming ability through cauliflower type of precipitation on the surface of the glass. Cytocompatibility was performed using human osteoblast cells (MG-63). Cytocompatibility of zinc-containing soda lime borosilicate glasses has shown significant results for bone tissue engineering applications.

Thermal conductivity of densified borosilicate glasses

In this work, we study the thermal conductivity of densified soda lime borosilicate glasses with varying B2O3/SiO2 ratio. Densification is induced by hot compression up to 2 GPa at the glass transition temperature. We find that the structural and mechanical properties of the glasses exhibit a similar response to hot compression as other oxide glasses, including increasing density, elastic moduli, and fraction of four-coordinated boron across the full compositional range. Generally, we find that thermal conductivity increases upon densification, but with a pronounced composition dependence, as silica-rich glasses exhibit only a minor increase (~8-10%) while borate-rich glasses exhibit a significant increase (>50%). We rationalize these variations in terms of topological constraint theory by showing a connection between the contribution of propagative vibrational modes to heat transfer and the volumetric constraint density across both as-made and densified samples. These findings thus provide insights into the linkages between structure and thermal conductivity.

Effect of Ultralight Filler on the Properties of Hydrated Lime Injection Grout for the Consolidation of Detached Historic Decorative Plasters.

Injection-grout density is an important parameter when its additional weight leads to consolidated decorative plasters becoming damaged. This is especially evident in larger detached areas. In this study, thin-walled soda–lime–borosilicate glass microspheres were used as a density-reducing constituent in hydrated lime grout mixtures. The normal density grout composition—one volume part hydrated lime and three volume parts inert limestone filler with 0.5% of the polycarboxylate ether-based superplasticiser—was modified with partial substitution of the limestone filler with lightweight glass microspheres. The following volumetric proportions between limestone filler and glass microspheres were used: 100%:0%, 67%:33%, 50%:50%, 33%:67%, and 0%:100%. With the increase of the glass microspheres’ volume, the density of the grout is gradually reduced. Furthermore, there is a decrease in the stability and injectability of fresh grout. In its hardened state, the grout’s strength again reduces gradually, but there is no significant change in the grout’s water absorption and water-vapour resistance. The resistance of the grout to freezing–thawing and heating–cooling cycles using distilled water or salt solution is highly improved when the microspheres are present.

Effect of vanadium oxide addition on thermomechanical behaviors of borosilicate glasses: Toward development of high crack resistant glasses for nuclear waste disposal

The effect of of V2O5 additions (up to 8 mol%) on the physical properties (e.g., density, glass transition temperature and refractive indices) and mechanical behaviors (e.g., hardness, fracture toughness, elastic modulus) of a soda-lime borosilicate glass with a composition of 60.2SiO2-16.0B2O3-12.6Na2O-3.8Al2O3-5.7CaO-1.7ZrO2 (mol%) have been investigated systematically. It was found that introducing V2O5 decreases the glass transition temperature and hardness while increases the refractive index and crack initiation load. Composition-property relationships, especially on mechanical properties, were examined in order to provide insights for the development of new glass materials with outstanding mechanical properties. The results show that V2O5 can be a glass component for engineering and insuring high crack resistant glasses and glasses with long-term stability. Additionally, elastic properties as a function of temperature were studied using Brillouin light scattering and temperature-independent elastic moduli behaviors were observed.

In vitro evaluation of niobia added soda lime borosilicate bioactive glasses

In the present study, systematic and detailed investigations have been reported, in terms of bioactivity, cytocompatibility and mechanical hardness of a synthetic material that is proposed as a bone implant material in in-vitro conditions. The objective of the present study is to explore the effect of niobium addition on bioactivity and cytocompatibility of soda lime borosilicate bioglasses. Synthesis of bioglasses is carried out by conventional melt-quenching method. Simulated body fluid is prepared by Tas method. The bioactivity study was done for twenty-one days of immersion in simulated body fluid. XRD, FTIR, and SEM-EDS are showed formation of hydroxyapatite layer on the niobium added soda lime borosilicate glass even at a higher concentration (10 mol %) of niobium content. Degradation test was performed as per ISO 10993. The results obtained from degradation studies have demonstrated that weight loss of niobia mixed soda lime borosilicate glasses decreased with the increase of niobia. Cytocompatibility study has been studied by MTT Assay with osteoblast cells (MG-63). Cell viability is not affected by the addition of niobium content. Niobium added soda lime borosilicate glasses are both bioactive and cytocompatible. Hence it can be concluded that niobia mixed borosilicate glasses may be used as potential material in bone tissue engineering.

Thermal expansion and dynamic mechanical analysis of epoxy matrix–borosilicate glass hollow particle syntactic foams

Syntactic foams are commonly fabricated with sodalime–borosilicate glass hollow microsphere fillers, which are susceptible to degradation after long-term or high temperature moisture exposure. In comparison, borosilicate glass hollow particles offer higher degradation resistance to moisture, lower thermal expansion, and higher softening temperature. This work explores borosilicate glass hollow microspheres for use as fillers in syntactic foams and studies their thermophysical properties. The coefficient of thermal expansion over the temperature range 35–90℃ was observed to decrease from 62.4 μ/K for the matrix resin to a minimum of 24.3 μ/K for syntactic foams, representing higher thermophysical stability of syntactic foams. Theoretical models are used to conduct parametric studies and understand the correlation between material parameters and coefficient of thermal expansion of syntactic foams. The dynamic mechanical analysis results show that the storage modulus of syntactic foams increases with increasing glass hollow microsphere wall thickness and with decreasing glass hollow microsphere volume fraction in the glassy region at 40℃. The β-relaxation of the matrix resin found at 66.1 ± 2.0℃ was suppressed in the majority of syntactic foams, further improving the stability around typical application temperatures.

β-Irradiation Effects on the Formation and Stability of CaMoO4 in a Soda Lime Borosilicate Glass Ceramic for Nuclear Waste Storage.

Molybdenum solubility is a limiting factor to actinide loading in nuclear waste glasses, as it initiates the formation of water-soluble crystalline phases such as alkali molybdates. To increase waste loading efficiency, alternative glass ceramic structures are sought that prove resistant to internal radiation resulting from radioisotope decay. In this study, selective formation of water-durable CaMoO4 in a soda lime borosilicate is achieved by introducing up to 10 mol % MoO3 in a 1:1 ratio to CaO using a sintering process. The resulting homogeneously dispersed spherical CaMoO4 nanocrystallites were analyzed using electron microscopy, X-ray diffraction (XRD), Raman and electron paramagnetic resonance (EPR) spectroscopies prior to and post irradiation, which replicated internal β-irradiation damage on an accelerated scale. Following 0.77 to 1.34 GGy of 2.5 MeV electron radiation CaMoO4 does not exhibit amorphization or significant transformation. Nor does irradiation induce glass-in-glass phase separation in the surrounding amorphous matrix, or the precipitation of other molybdates, thus proving that excess molybdenum can be successfully incorporated into a structure that it is resistant to β-irradiation proportional to 1000 years of storage without water-soluble byproducts. The CaMoO4 crystallites do however exhibit a nonlinear Scherrer crystallite size pattern with dose, as determined by a Rietveld refinement of XRD patterns and an alteration in crystal quality as deduced by anisotropic peak changes in both XRD and Raman spectroscopy. Radiation-induced modifications in the CaMoO4 tetragonal unit cell occurred primarily along the c-axis indicating relaxation of stacked calcium polyhedra. Concurrently, a strong reduction of Mo6+ to Mo5+ during irradiation is observed by EPR, which is believed to enhance Ca mobility. These combined results are used to hypothesize a crystallite size alteration model based on a combination of relaxation and diffusion-based processes initiated by added energy from β-impingement and second-order structural modifications induced by defect accumulation.

Mechanical Properties of Epoxy Matrix-Borosilicate Glass Hollow-Particle Syntactic Foams

Abstract Syntactic foams are particulate composites, which consist of a dispersion of hollow particles in a matrix. These materials are extensively used in the structures of underwater vehicles, but existing studies have shown that the commonly used soda-lime–borosilicate glass hollow particles are susceptible to significant degradation upon exposure to moisture. In this work, epoxy matrix syntactic foams are fabricated using borosilicate glass hollow particles that are not susceptible to degradation in wet environments. Nine compositions are fabricated and tested for quasi-static compressive properties, high-strain-rate compressive properties, and flexural properties. The quasi-static compressive strength and energy absorption are found to increase with composite density and the compressive strength is found to exceed that of similar syntactic foams using soda-lime–borosilicate hollow particles. The syntactic foams were observed to have 70 %–108 % higher peak stress in the high-strain-rate regime compared to the quasi-static values but the strength within the high-strain-rate regime was not dependent on the strain rate. The flexural properties were shown to have strong sensitivity to volume fraction of hollow particles.

Rare-earth silicate crystallization in borosilicate glasses: Effect on structural and chemical durability properties

Due to their low solubility, some elements, such as lanthanides, can lead to crystalline phases in borosilicate glass during cooling. The impact of rare earth (lanthanum and neodymium) silicate crystallization on glass structural configuration as well as on glass chemical durability was investigated in soda-lime borosilicate glasses. Partially crystallized glasses containing a single Ca2RE8(SiO4)6O2 (RE=La, Nd) phase (ranging from 1 to 36wt.%) were synthesized by heat treating homogeneous glasses. Structural characterizations of vitreous and crystalline parts were carried out by 29Si, 11B, 23Na and 17O MAS and MQMAS NMR. The crystallization leads to a reorganization of the cation distribution around the rare earth elements. By keeping a part of the lanthanum and the calcium, crystallization causes a decrease in the number of NBOs in the vitreous part. A part of the sodium, initially near the lanthanum, becomes available to form Si–O–Na bonds and to convert trihedral boron into tetrahedral boron. Through the study of the alteration of different materials – homogeneous, crystallized and surrounding glasses, rare earth silicate ceramics, and separated mixtures of glass and crystals – a precise description could be made of the influence of the presence of crystals has on chemical durability. For the various alteration regimes, it was thus shown that the alteration kinetics increase proportionally to the crystal content, and that apatite-type crystals do not lead to a composition gradient on the glass–crystal interface. Although the crystals formed were more durable than the vitreous matrix, the chemical durability of partially crystallized glasses depends on the composition and structure of the surrounding glass.

Photon Interactions Study of Bi<sub>2</sub>O<sub>3</sub>-Na<sub>2</sub>O-CaO-SiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Glasses

The Bi2O3 doped with soda lime borosilicate glasses in composition xBi2O3 : 15Na2O : 10CaO : 20B2O3 : (55-x)SiO2 at different concentrations (x = 0, 5, 10, 15, 20, 25 mol%) were studied the photon interactions. The total mass attenuation coefficient, coherent, incoherent, photoelectric absorption and pair production of prepared were studies using WinXcom Program at 1keV to 2MeV. The result of total mass attenuation coefficient and photoelectric absorption were decreases but discontinue because of photoelectric absorption edge at low energy. The photoelectric effect shows the main interaction at the low energy and decrease with increasing of photon energy. The higher photon energy the incoherent scattering found to be the main interaction. But at the photon energy 1.022 MeV, the pair production will be occurs and found to be the main interaction at the photon energy higher than 1.022 MeV.

Cation Diffusivity and the Mixed Network Former Effect in Borosilicate Glasses

Understanding the structural origins of cationic diffusion processes in silicate glasses is important for high-tech applications of silicate glasses. For glasses with more than one network former, transport properties such as diffusivity are often nonlinear functions of the particular distribution of these network formers, a phenomenon known as the mixed network former effect. Here, we investigate the sodium-potassium interdiffusion (D̅Na-K) and the calcium inward diffusion (DCa) in soda lime borosilicate glasses with varying silica/borate ratio but constant modifier content. Indeed, the structural organization of borosilicate glasses results in a pronounced nonlinear composition dependence of D̅Na-K and DCa (i.e., the mixed network former effect). Initial addition of B2O3 to the glass system results in a significant decrease in both diffusivities, whereas the change in diffusivity per mole of added B2O3 decreases with increasing B2O3 concentration. Besides the influences of water content and atomic packing degree, we find that 99% of the composition dependence of log D̅Na-K can be ascribed to the change in concentration of tetrahedral boron groups. This indicates that the formation of BO4/2 groups slows down diffusion processes of alkali and alkaline earth ions. Therefore, the mixed network former effect of the studied glass series is linked with the change of the concentration of tetrahedral boron groups, which is caused by the interactions between the different types of network formers.

Mechanisms of boron coordination change between borosilicate glasses and melts

The structure of two borosilicate glasses and melts has been investigated by neutron diffraction coupled with Reverse Monte Carlo (RMC) simulation. For both compositions (10B2O3⋅30Na2O⋅60SiO2 and 10B2O3⋅15Na2O⋅15CaO⋅60SiO2), the fraction of tetrahedral boron ([4]B) drops from 0.7 to 0.3 from the glass to the melt. The change from a modifying to a charge compensating role of cations during quench is related to the boron coordination change. These molecular scale modifications explain the low viscosity of alkali/alkaline-earth borosilicate melts relative to alkali/alkaline-earth silicate melts, as the viscous flow is enhanced with the proportion of [3]B. RMC simulations of soda borosilicate glass and melt show a preferential interbonding between B and Si polyhedra. Such medium range order interbonding is unfavored in the soda-lime borosilicate glass showing a nearly random network. The effect of Ca enhancing the proportion of B–B pairs is here highlighted.

Production and Properties of 316L Stainless Steel Cellular Materials and Syntactic Foams

316L steel syntactic foams incorporating different mass percentages of soda lime borosilicate glass microspheres (3M™) as porosity‐introducing particles are produced via metal powder injection moulding. Sintering is performed at 1200°C under controlled atmosphere for 1.5, 3, and 6 h. Microstructural features are examined using optical and scanning electron microscopy (SEM) as well as focused ion beam (FIB) preparation and EDX analysis. Response to quasi‐static compressive and tensile loads is studied and interpreted based on structural characterization results. Melting of microspheres is observed, but cavities originally occupied by microspheres are maintained, while glass inclusions form in the surrounding matrix. A qualitative explanation of the underlying process is given. Evaluation of the stress–strain curve reveals a comparatively weak expression of the stress plateau matching the relatively low porosity. Analysis of tensile fracture surfaces indicates a shift of failure initiation sites from spinel type MnCr2O4 phases in the reference material to glass inclusions in foam samples. No major influence of sintering time on structural or mechanical characteristics is identified. Despite the adverse effects of microsphere melting, mechanical performance of 316L syntactic foams matches similar materials having Fe and Fe‐based alloy matrices.

Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

The local environment of europium in soda-lime borosilicate glasses with a range of La2O3 content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90°C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell.

Influence of lanthanum on borosilicate glass structure: A multinuclear MAS and MQMAS NMR investigation

The physical and chemical properties of silicate glasses containing rare-earth elements (REEs), either as dopants or at higher concentrations, are sensitive to the REE structural and chemical environment. An unambiguous role of REEs in the glass structure still remains difficult to define because many configurations may exist and are strongly composition-dependent. The structural configuration of lanthanum and its interactions with sodium and calcium are examined here in borosilicate glasses. The impact of lanthanum and calcium substituted for sodium on the boron speciation is investigated by 11B MAS NMR. The resulting 29Si MAS NMR spectra and their interpretations are discussed. A quantitative approach of 17O MQMAS NMR data with the reconstruction of 17O NMR parameter distributions provides an overview of lanthanum distribution and its interactions with the other cations in the vitreous network. No clustering of lanthanum atoms is observed; they are uniformly distributed in the glass structure, surrounded by about 6 non-bridging oxygen atoms and mixed with sodium and calcium atoms to the detriment of the number of BO4 groups. These data provide a better understanding of the addition of rare earths in the glass and of the conditions favorable to their uniform distribution in soda-lime borosilicate glass matrices.

Impact of soda-lime borosilicate glass composition on water penetration and water structure at the first time of alteration

In this study, the impact of soda-lime borosilicate glass composition and particularly the effect of charge compensators such Ca and Na and, of network formers such Si and Zr, on water penetration and water structure at the first time of alteration were investigated. Two non-destructive techniques were combined: the Fourier transform infrared spectroscopy in attenuated total reflection geometry to precise the predominant alteration mechanisms and assess the water structure in altered zone and the grazing incidence X-ray reflectometry to determine the thickness of the altered glass zone allowing to calculate the water diffusion coefficients through the glasses. The results of glass alteration at pH=3 and 30°C have shown that hydrolysis was the predominant mechanism after few seconds for glass having a high amount of non-binding oxygen. For the other glasses, which for the diffusion was the limiting reaction, the calculated water diffusion coefficients were comprised between 10−21 and 10−19m².s−1 and vary as a function of glass composition. An activation energy of 76.9kJ.mol−1 was calculated and appears to be higher than inert gas diffusion through the glass highlighting that water molecules strongly interact with the glass matrix.

Optical Characterization of Soda Lime Borosilicate Glass Doped with TiO2

In this work, TiO2 doped in soda lime borosilicate glasses were prepared with chemical compositions of 10Na2O: 30B2O3: 10CaO: (50-x)SiO2: xTiO2 where x = 0.0, 2.0, 4.0, 6.0, 8.0 and 10.0mol, respectively, and investigated their physical and optical properties. The results showed that, density of glasses did not clearly depend on TiO2 concentration. The molar volumes were increased with increasing of TiO2 concentration, due to increase of nonbridging oxygen. The refractive indices were increased with increasing of TiO2 concentration. The absorption edge of undoped glass is occurred at the wavelength around 325nm. It is also observed that the positions of absorption edge shift towards red as the content of TiO2 increases. The optical band gaps were slightly decreased with the increasing of TiO2 and results in the increase of bonding defect and non-bridging oxygen. This leads to an increase of the degree of localization of electrons thereby the increase of donor center in the glass matrix.

First investigations of the influence of IVB elements (Ti, Zr, and Hf) on the chemical durability of soda-lime borosilicate glasses

The influence of IVB elements (Zr, Ti, and Hf) on the glass structure and on the alteration kinetics of soda-lime borosilicate glasses has been studied at various stages of glass leaching corresponding to the initial dissolution rate, rate drop, and residual rate regimes. The effect of these elements on the limiting mechanisms of the glass durability as well as the chemistry of both solution and alteration layer are inter-related, depending on the reaction progress. The effect of IVB elements on the glass structure was investigated using 11B MAS NMR. The IVB elements are compensated primarily by Na rather than Ca, at the expense of tetracoordinated boron. The addition of HfO 2 or ZrO 2 decreases the initial dissolution rate in a similar way. Moreover, adding ZrO 2 limits the rate drop in saturated media. The initial dissolution rate decrease is less significant when Ti is added, and a quick drop of the dissolution rate is observed up to 4 mol% TiO 2. At low IVB element concentration, glasses containing Ti and Zr show different residual rates arising from the precipitation of magadiite (Na 2Si 14O 29·11H 2O), at the surface of Ti-bearing glasses. The influence of IVB elements on glass alteration indicates that, unlike Ti, Zr and Hf plays a similar role in the structure of borosilicate glasses.

Phosphate ion removal from a solution by soda-lime borosilicate glass

The excessive phosphate ion content in industrial wastewater causes water eutrophication. The objective of this study is to develop a new method of phosphate ion removal from wastewater using soda-lime borosilicate glass. Soda-lime borosilicate glass with high content of modifiers is reacted in a solution containing phosphate ions. Ca2+ ions that are leached out of the glass combine with P5+ ions in a solution to form hydroxyapatite crystals on the glass surface. The phosphate ions can thereby be removed from the solution. The phosphate ion removal rate was highest when glass containing 20–30mol% of CaO was reacted in a solution with pH of 3.0. The phosphate ion removal rate was faster when the glass was reacted with the solution under a dynamic condition than under a static condition. The elimination rate also strongly depended on the surface area of the glass.