Chemical Composition Of Glass Research Articles

シリコンとガラスの陽極接合部に及ぼすガラス材料の影響

Borosilicate glass is often used as a material during the anodic bonding process because the thermal expansion coefficient of glass is very close to that of silicon. However, in recent years, a new chemical composition of glass was developed as a joinable glass at a lower bonding temperature. To ensure the reliability of anodic bonding joints of the new glass to silicon, it is necessary to clarify the influence of bonding conditions and the comparison of performance of anodic bonding joints of new glass and borosilicate glasses. In this study, the effect of the bonding conditions on the tensile strength and thickness of the reaction layer and bonding charge density of anodic bonding joint of three glasses (TEMPAX, PYREX, SW-YY) to silicon was comparatively investigated. The main results obtained are as follows. The anodic bonding joints using SW-YY was bonded at a lower bonding temperature than TEMPAX and PYREX. Under the same bonding conditions, thickness of the reaction layer on joints of SW-YY to silicon was the thickest of all. Independent of glasses, the increase in the bonding charge density resulted in stabilized tensile strength and the fracture modes changed to glass fractures. Thus, measuring the bonding charge density during the anodic bonding process helped to clarify the effects of the bonding conditions on the anodic bonding joints of glass to silicon.

From Siena to Barcelona: Deciphering colour recipes of Na-rich Mediterranean stained glass windows at the XIII–XIV century transition

Abstract This paper offers new insights on the evolution of colour recipes for Na-rich Mediterranean stained glass, taking as a guideline the results of the study of the Duccio di Buoninsegna's rose window (1288–89 AD) at the Duomo (Cathedral) of Siena (Italy) and the Santa Maria de Pedralbes presbytery windows of the church at the royal monastery in Barcelona (1326–27 AD). In order to decipher the colour recipes in an original set of glass pieces, a number of chemical analyses have been performed, namely quantitative EPMA on thin sections cutting orthogonally the glass surface. This comparative approach is useful since the studied glass is well preserved in terms of good chemical conservation against corrosion and biological attack. Also, chemical composition of glass provides evidence of preservation of homogeneous original glass sets at each site. The Siena samples are representative of traditional colour production, as explained by the monk Theophilus two centuries before (regarding yellow, pink and colourless glass) or as is well known before Theophilus for Co-blue glass. Also, some chemical data on Cu–Fe-rich green glass provide evidence tentatively related to the use of metal-rich slag as colouring component. The Barcelona samples offer evidence of new recipes (i.e. yellow glass) and hence look more evolved from the glassmaker's point of view, in spite of the more pristine artistic features. Both glass windows can be regarded milestones in the interpretation of technological evolution with the introduction of new colour recipes at the XIII–XIV century's transition.

On the structural units in titanium-containing glasses and their influence on the opacity of glass coatings

A probable order of the formation of structural units in glasses of the Na2O-B2O3-SiO2, Na2O-TiO2-SiO2, and Na2O-B2O3-SiO2-TiO2 systems as a function of the alkali oxide content is analyzed in terms of the strengths of the cation-oxygen bonds of the glass components. The principle of the structure formation in silicate glasses is proposed. It is demonstrated that the chemical composition of glasses can be used to predict the existence of structural groups favoring the crystallization of titanium-containing phases in the glass and, consequently, the influence of the composition on the opacity of enamel coatings.

Transport phenomena in glass technology (Review)

The role of transport phenomena and technological processes in glass production is noted. The salient features of a change in transport phenomena accompanying changes of the temperature and chemical composition of glasses for fused and solidified states of glass are examined. The interrelationship of transport phenomenon is also examined. Glass forming melts possess a high viscosity. The latter has a large effect on transport phenomena associated with particle motion; this effect is also expressed by definite relations. The results of experimental and theoretical investigations, presented in the scientific and technical literature, are discussed from structural and technological standpoints.

Effect of the glass composition on corrosion of zirconium-containing refractories in a glass-melting furnace (a review)

Different chemical compositions of glasses and the individual characteristics of their reaction with zirconium-containing refractories are examined. When such refractories are used for lining glass-melting furnaces, it is necessary to consider the chemical compositions of the glass which will be melted in these furnaces.

Origin of Chinese ancient glasses—study on the earliest Chinese ancient glasses

The earliest Chinese ancient glasses before the West Han Dynasty (200 BC) from different regions are studied. The glass samples were unearthed from Hunan, Hubei, Yunnan, Sichuan, Guizhou, Guangdong and Xinjiang of China. The chemical composition of these glasses samples is analyzed by proton induced X-ray emission (PIXE) technique, energy dispersive X-ray fluorescence (EDXRF) method and inductively coupled plasma atomic emission spectrometry (ICP-AES). It is shown that the glass chemical compositions belong to barium-lead silicate BaO-PbO-SiO2, potash soda lime silicate K2O (Na2O)-CaO-SiO2 (K2O/Na2O>1), soda potash lime silicate Na2O (K2O)-CaO-SiO2 (K2O/Na2O<1) and potash silicate K2O-SiO2 glass systems, respectively. The origins of the earliest Chinese ancient glasses are discussed from the archaeological and historical points of view. These four types of Chinese ancient glasses were all made in Chinese territory using local raw materials. The glass preparation technology was related to the Chinese ancient bronze metallurgy and proto-porcelain glaze technology. The glass technology relationship between the East and the West is analyzed at the same time.

Classification and Technology of Byzantine Mosaic Glass

Glass-making is a very sophisticated skill and the contribution given by the chemical analyses of glass materials is fundamental for the classification of glass types and for identifying compositional groups according to consistent characteristics that can be associated with chronological and geographical differentiations. The chemical composition of glasses is particularly complex: to a few basic constituents many components were added, either derived from impurities in the raw materials or intentionally incorporated into the glass mix. The field of study concerning the chemical composition and the technology of Byzantine mosaic production has not been dealt with in a systematic manner and certainly not exhaustively from the view point of classification according to the reconstruction of chronological and geographical development. Nevertheless, it is of great interest because it is probable that during the Byzantine period the production of mosaic glass was greater than for any other type of glass. We propose a methodology for classifying Byzantine mosaic glasses on the basis of simple statistical treatment of the chemical composition data. Compositional data relative to basic and accessory constituents together with colorants were analysed and elaborated through binary diagrams. Byzantine glasses are also compared to glasses of different epoch and provenance.

Porosity in ancient glass from Syria (c. 800 AD) using gas adsorption and atomic force microscopy

AbstractGas adsorption and atomic force microscopy have been used to quantify and compare the porosity, surface area and surface characteristics of five samples from Raqqa in northern Syria dating to ca. 8th century AD. High‐quality high‐pressure liquid chromatography (HPLC) glass was also analysed to compare the results with these characteristics of modern glass. All five ancient samples were found to have some porosity across the microporous (up to 2 nm) and the mesoporous (2–50 nm) range. The reasons for this porosity are not entirely clear at present but are likely to be due to the manufacturing methods used, including the raw materials. A correlation was found between glass chemical composition (especially the total alkali) and pore size, inferring that the melting temperature is one of the parameters that affects the development of pores. The work in this paper presents the preliminary findings from the study of porosity in ancient glass. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Thermal study of the influence of chemical bond ionicity on the glass transformation in (Na2O, CaO, MgO)-Al2O3-SiO2glasses

The relation between change of the specific heat (ΔC p) accompanying the glass transformation and the chemical composition of glasses (Na2O, CaO, MgO)-Al2O3-SiO2 system has been studied. The exchange of modifiers in the glass structure causes the ΔC p increase in the sequence Na>Ca>Mg. Change the glass network composition by introducing Al into it makes smaller increase of the ΔC p values. It has been shown that degree of ΔC p value changes is dependent on the iconicity/covalence of chemical bonds of cations with oxygen of glass structure network.

Mechanical spectroscopy methods for the quantitative analysis of intergranular glass viscosity in polycrystalline ceramics

Mechanical spectroscopy methods for the analysis of viscous behavior of grain boundaries are described and applied to glass-bonded polycrystalline ceramics. Emphasis is placed on the analysis of a high-temperature peak, which originates from grain-boundary sliding relaxation, with respect to: (i) peak shift with damping frequency change; (ii) peak intensity for a given testing geometry and amount of glassy phase; and, (iii) peak morphology characteristics. According to analyses (i) and (ii), an activation energy for intergranular viscous flow and the magnitude of glass-phase viscosity are quantitatively determined. The morphology of the peak depends on the activation energy for intergranular viscous flow, but it is also affected by the volume fraction of intergranular glass and by the presence of chemical gradients at grain boundaries. In addition microstructural inhomogeneities, such as grain size distribution and grain texture, can affect the peak morphology. Chemical and microstructural inhomogeneities generate spectra of activation energies and relaxation times, respectively. With inherently different characteristics, they both contribute to peak broadening. Internal friction experiments as a function of glass volume fraction and chemical composition experimentally confirmed that the above features are actually represented in the internal friction curve of a ceramic polycrystal as a function of temperature.

Calculation of the Structural Linear Expansion Coefficient from the Chemical Composition of Glasses in the R2O(RO)–Al2O3–B2O3 (R = Li, Na, Ca, and Ba) System

The regularities of the influence of the glass composition on the structural linear expansion coefficient in the glass transition range are analyzed using the published data obtained in systematic experimental investigations of glasses in the R2O(RO)–Al2O3–B2O3 (R = Li, Na, Ca, and Ba) system. A method is proposed for calculating the structural linear expansion coefficients of these glasses from the chemical composition with a mean relative error of ∼10%. The possibilities of extending the composition range covered by the calculation are considered.

Evaluation of Crystallization Capacity of Glasses

A temperature-concentration dependence of the linear velocity of crystal growth (LVCG) of diopside for potassium-bearing glasses of the system CaO – MgO(Al2O3) – SiO2 is determined based on adaptation of the Turnbull-Cohen theoretical equation, and a relationship between the LVCG of devitrite and cristobalite and the chemical composition of glasses located in the respective areas on the phase diagram of the Na2O – CaO – SiO2 system phase diagram is established.

Application of Positron Annihilation Lifetime Technique for γ-Irradiation Stresses Study in Chalcogenide Vitreous Semiconductors

The influence of γ-irradiation on the positron annihilation lifetime spectra in chalcogenide vitreous semiconductors of As-Ge-S system has been analysed. The correlations between lifetime data, structural features and chemical compositions of glasses have been discussed. The observed lifetime components are connected with bulk positron annihilation and positron annihilation on various native and γ-induced open volume defects. It is concluded that after γ-irradiation of investigated materials the γ-induced microvoids based on S1–, As2–, and Ge3– coordination defects play the major role in positron annihilation processes.

Glass recycling in cement production—an innovative approach

An innovative approach of using waste glass in cement production was proposed and tested in a laboratory and cement production plant. The laboratory characterization of 32 types of glass show that the chemical composition of glass does not vary significantly with its color or origin but depends on its application. The alkali content of glass, a major concern for cement production varies from 0 to 22%. For the glass bottles mainly found in Hong Kong waste glasses, the alkali content (Na 2O) ranges from 10 to 19% with an average around 15%. There is no significant change of the SO 2 content in the gas exhaust of the rotary kiln when about 1.8 t/h of glass bottles were loaded along with the 280–290 t/h raw materials. The content of NO x , mainly depends on the temperature of the kiln, does not show significant change either. The SO 3 content of the clinker is comparable with that obtained without the loading of glass. The alkaline content shows a slight increase but still within three times the standard deviation obtained from the statistical data of the past year. The detailed analysis of the quality of the cement product shows that there is not any significant impact of glass for the feeding rate tested.

Gamma-ray attenuation coefficients in bismuth borate glasses

Mass attenuation coefficients of glasses in the system: xBi 2O 3(1− x)B 2O 3 ( x=0.30, 0.35, 0.40, 0.45 and 0.55) were determined at 356, 662, 1173 and 1332 keV photon energies using a narrow beam transmission method. Appreciable variations were observed in these coefficients due to changes in the chemical composition of glasses. These coefficients were then used to determine effective atomic numbers of glass samples, which were found to be constant with bismuth concentration and energy.

Electret properties of radiation-charged phosphate glasses

The process of formation of a surface charge in phosphate glasses depending on polarization conditions is investigated. A relationship is established between the chemical composition of glass and its capacity for forming internal electric fields under radiation for glasses of type 0.50P2O5 – 0.45RO – 0.05R2O3.

PROCESSES OCCURRING IN SYNTHESIS OF IRON-BEARING GLAZE FRITS

The authors consider the processes of silicate and glass formation in iron-containing glass batches based on technical materials (oxides and carbonates) and using magma rock (metadiabase). The specific features of these processes depending on the chemical composition of glass are identified. It is established that the crystalline phases arising in silicate formation persist in the glass melt in the form of structural groups. The possibility of decreasing the temperature of glaze-frit synthesis in the case of using metadiabase is considered.

Influence of glass chemical composition on the Na–O bond distance: a 23Na 3Q-MAS NMR and molecular dynamics study

The sodium environment in oxide glasses was investigated by 23Na multiple-quantum magic-angle spinning (MQ-MAS) NMR spectroscopy and compared with molecular dynamics simulations. In the experimental approach, a spectrum-inversion was employed taking into account the transfer efficiency involved in the MQ-MAS experiment. This allowed the reconstruction of the underlying two-dimensional distribution of the isotropic chemical shift correlated with the quadrupolar interaction. The isotropic chemical shift distributions were extracted from the MQ-MAS spectra to infer Na–O distance distributions. First, a Na 2O–2SiO 2 glass and its crystal analogue were characterized by this method to observe the disorder effect in the glass through the Na–O distance distribution. Thereafter, in order to study the influence of the chemical composition on the Na–O distance and distribution, additional glasses were investigated with NMR and simulation: Na 2O–5SiO 2, Na 2O–2CaO–3SiO 2, Na 2O–Al 2O 3–3SiO 2 and Na 2O–B 2O 3–3SiO 2. The molecular dynamics results are in good agreement with the experimental findings. The mean Na–O distance is higher when network formers are added to the sodium silicate glass. The effects on the Na–O distance distribution are also discussed. The simulation relates these results to the existence of several types of Na: near the non-bridging oxygen of the silicon, or as aluminum or boron charge compensator. This can be explained through charge and geometric effects.

Structure of the glasses in the (0.15Ga 2S 3×0.85GeS 2) 1− x–(Nd 2S 3) x system

The structure of the glasses in the (0.15Ga 2S 3×0.85GeS 2) 1− x −(Nd 2S 3) x system has been investigated by X-ray scattering. From the width of the first sharp diffraction peak the correlation length ( R c) of the medium-range order has been calculated. The dependence of R c on the chemical composition of glasses is discussed in the frame of the model of strong co-ordination ability of Nd atoms. The proposed model describes the experimental results.

Concentration dependence of impurity absorption in chalcogenide glasses of the Ge-Sb-S system

We have investigated the IR spectra of chalcogenide glasses of the triple Ge-Sb-S system in Sb2S3-GeS2 and Sb2S3-Ge2S3 sections. We have analyzed the specific features of the appearance of intense vibrational bands of absorption of various structural fragments depending on the chemical composition of glasses.