• Title/Summary/Keyword: Chemical composition of glass

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A Comparison in Characteristics of Chemical Composition of Glass Vessels Excavated from Neungsalli Temple in Buyeo, Korea, from Baekje Period

  • Koh, Min Jeong;Kang, Hyung Tae;Kim, Na Young;Kim, Gyu Ho
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4173-4179
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    • 2012
  • From Neungsalli Temple located in Buyeo, ancient glass vessel fragments were discovered along with hundreds of glass beads. In this research, we used SEM-EDS to analyze glass vessel fragments and beads excavated from Neungsalli Temple. Then, we analyzed their chemical composition and examined their characteristics. In particular, we investigated a relationship between glass vessels from Neungsalli temple and Hwangnamdaechong (South tomb). The result of our experiment showed that the glass artifacts from Neungsalli temple were all soda glass. To be specific, the vessel fragments were soda-lime glass and spherical beads were high-alumina soda glass. Then, we compared glass vessel fragments from Neungsalli temple to glass vessels excavated from Hwangnamdaechong. Glass vessels from both sites turned out to be soda lime glass. We classified them further based on raw material used for soda - natron and marine plant ash.

Chemical Durability of Simulated Waste Glasses (모의 폐기물유리의 화학적 내구성)

  • 현상훈;송원선
    • Journal of the Korean Ceramic Society
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    • v.26 no.4
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    • pp.521-531
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    • 1989
  • The dependence of the chemical durability of simulated waste glasses containing the simplified waste similar to the SRP waste on compositions of host glasses, amounts of waste loading, and kinds of leachants has been investigated as a basic study on the waste immobilization through vitrification. The maximum limit of the amount of waste loading for glassforming with the host sodium borosilicate glasses selected in this study was 50wt%. The chemical durability of waste glasses whose host glass belonged to the immiscible composition region was much higher than that of waste glasses whose host glass belonged to the miscible composition region. The former waste glass showed lower chemical durability in deionized and silicate waters than in brine, while the latter glass showed the lowest chemical durability in deionized and silicate waters than in brine, while the latter glass showed the lowest chemical durability in silicate water. It was also observed that the total leaching rates in brine were noticeably small in comparison with those in other solutions. The composition of the host borosilicate glass which was suitable for the treatment of the waste through vitrification was found to be 25 Na2O-5B2O3-70SiO2(wt.%).

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Analysis and Investigation of Archaeological Chemistry on the Class Beads of Dujeong-dong site of Cheonan, Korea (천안 두정동 출토 유리구슬의 고고화학적 분석 고찰)

  • Song, Yu-Na;Kim, Gyu-Ho
    • Journal of Conservation Science
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    • v.18 s.18
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    • pp.5-18
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    • 2006
  • Dujeong-dong site of Cheonan is known as the site of Baekje period in the first half of the fourth century. This study investigated the visible properties and the chemical composition of the 18 pieces of the glass found in the site, and considered scientific properties and periodic interrelationship of the glass on the basis of the analysis result. The observation of the visible properties and microstructure of ancient glass was performed with both an electron microscope and an optical microscope, and the chemical composition was conducted by way of both quantitative and qualitative analysis using Scanning Electron Microscope(SEM) with Energy Dispersive Spectrometer(EDS). In the analysis result, various chemical composition systems are identified in the glass beads of Dujeong-dong site, such as lead-barium, soda and potash glass, and also different shapes were found such as gold foil glass beads, tubular beads, and round beads. It is estimated that the classification of glass by means of its chemical composition was also closely related to the color of glass.

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The Chemical Composition and Working Techniques of the Glass Beads Excavated in the Jisan-dong No. 73-74 Ancient Tombs, Goryeong (고령 지산동 73~74호분 출토 유리구슬의 제작 기법과 화학 조성)

  • Kim Nayoung;Kim Euna;Kim Gyuho
    • Conservation Science in Museum
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    • v.31
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    • pp.21-37
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    • 2024
  • This paper sought to garner an understanding of Daegaya glass culture by observing the micro-structure and analyzing the chemical composition of 43 glass beads excavated from the No.73 and 74 ancient tombs in Jisan-dong, Goryeong, which are estimated to have a central age of 5th century CE. The visible characteristics and micro-structure of these artifacts were observed with a optical microscope and an scanning electron microscope, while their chemical composition was analyzed with an energy-dispersing spectrometer attached to the scanning electron microscope. As a result, the glass beads of Jisan-dong, Goryeong were identified to have been formed using various methods such as drawing, casting, and folding techniques, with the majority molded by the drawing technique. In terms of chemical composition, 32.6% were in the potash glass group and 67.4% in the soda glass group, with the latter divided into various fluxes such as high alumina glass, netron glass, and plant ash glass. Compared to Baekje's cultural region in the same age, the composition of these ancient glass artifacts demonstrates a high share of the potash glass group. This shows that, despite the shift from the potash glass group to the soda glass group in ancient Korean glass culture, glass composition differs from region to region or depending on the cultural sphere of influence. In the soda glass group, high-alumina glass comprised 23.3%, natron glass 43.0%, and plant ash glass was 1.2%. Among them, the main type of Korean soda glass is high-alumina glass, as natron glass and plant ash glass are known to have appeared later, but the results of scientific analysis of the glass beads excavated in Jisan-dong can be expected to provide important clues about the inflow and transformation of ancient glass on the Korean Peninsula. In the No. 73, 74, and 74-1 ancient tombs, which were found to have been built in chronological order by the excavation survey, the glass beads showed only slight variations depending on their production period. Nonetheless, the chemical composition of glass is deemed to have a close correlation to color.

Effects of Chemical Etching with Sulfuric Acid on Glass Surface

  • Jang, H.K.;Chung, Y.L.;S.W.Whangbo;C.N.Whang;Lee, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2000.02a
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    • pp.165-165
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    • 2000
  • Glass slides were chemically etched with sulfuric acid using five different methods. we investigated the effects of the chemical etching conditions on such properties as chemical composition, surface roughness, and the thermal stability of the glass. Sodium and carbon atoms in the surface of the glass are effectively eliminated by chemical etching with sulfuric acid. The glass slides were boiled for 30 min in 95% sulfuric acid and were depth profiled at room temperature with X-ray photoelectron spectroscopy (XPS), the Na ls signal was not detected in the detection limit of XPS. Surface morphology of the glass was very different depending on the concentration of sulfuric acid. The surface of the glass etched with 50% sulfuric acid was rougher than that of glass etched with 95% sulfuric acid. The sodium concentration of the glass boiled for 30 min in 95% sulfuric acid was nearly zero at the glass surface, and the sodium composition changed very little with annealing temperatures up to 35$0^{\circ}C$ in a vacuum environment. However the sulfur concentration at the glass surface due to the sulfuric acid increased with increasing temperature.

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Na Borosilicate Glass Surface Structures: A Classical Molecular Dynamics Simulations Study (소듐붕규산염 유리의 표면 구조에 대한 분자 동역학 시뮬레이션 연구)

  • Kwon, Kideok D.;Criscenti, Louise J.
    • Journal of the Mineralogical Society of Korea
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    • v.26 no.2
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    • pp.119-127
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    • 2013
  • Borosilicate glass dissolution is an important chemical process that impacts the glass durability as nuclear waste form that may be used for high-level radioactive waste disposal. Experiments reported that the glass dissolution rates are strongly dependent on the bulk composition. Because some relationship exists between glass composition and molecular-structure distribution (e.g., non-bridging oxygen content of $SiO_4$ unit and averaged coordination number of B), the composition-dependent dissolution rates are attributed to the bulk structural changes corresponding to the compositional variation. We examined Na borosilicate glass structures by performing classical molecular dynamics (MD) simulations for four different chemical compositions ($xNa_2O{\cdot}B_2O_3{\cdot}ySiO_2$). Our MD simulations demonstrate that glass surfaces have significantly different chemical compositions and structures from the bulk glasses. Because glass surfaces forming an interface with solution are most likely the first dissolution-reaction occurring areas, the current MD result simply that composition-dependent glass dissolution behaviors should be understood by surface structural change upon the chemical composition change.

Compositions and Characteristics on the Glass Beads from Jeongjang?ri Site in Geochang, Korea (거창 정장리 유적 출토 유리구슬의 화학 조성과 특징)

  • Yun, Ji Hyeon;Kim, Gyu Ho
    • Journal of Conservation Science
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    • v.32 no.1
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    • pp.63-73
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    • 2016
  • This study defined material and characteristics of 24 glass fragments and 26 whole glass beads. The feature of glass beads shape are divided into 5 types following color, size, weathering condition and manufacturing techniques. Through the chemical composition, the first and second type is soda glass, the third type is potash glass, the fourth and fifth type is lead barium glass. This site showed the aspect that the chemical composition is changed according to the feature of glass shape and was found that various chemical compositions. Looking at the flow of glass culture, the tomb that are lead barium glass IItype and potash glass I, IItype is relatively preceding period and the tomb that are soda glass and lead barium glass IIItype is following period.

A Study on the Properties and Fabrication of Bulk Forming GeSe Based Chalcogenide Glass for Infrared Optical Lens (적외선 광학렌즈 제작을 위한 GeSe의 벌크 제작 및 특성 연구)

  • Bae, Dong-Sik;Yeo, Jong-Bin;Park, Jung-Hoo;Lee, Hyun-Yong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.9
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    • pp.641-645
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    • 2013
  • Chalcogenide glass has superior property of optical transmittance in the infrared region. Glass made using Ge-Se how many important optical applications. We have determined the composite formular of $Ge_{0.25}Se_{0.75}$ to be the GeSe chalcogenide glass composition appropriate for IR lenses. Also, the optical, thermal and physical characteristics of chalcogenide glass depended on the composition ratio. GeSe bulk sample is produced using the traditional melt-quenching method. The optical, structural, thermal and physical properties of the compound were measured by using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Differential scanning calorimeter (DSC), and Scanning electron microscope (SEM) respectively.

Preparation of Foamed Glass Block from Recycled Soda-lime-silicate Glasses by Chemical Composition Control (폐 소다석회 유리의 조성조절에 의한 발포유리블록의 제조)

  • Kim, Jung-Min;Lee, Chul-Tae
    • Applied Chemistry for Engineering
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    • v.24 no.4
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    • pp.382-390
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    • 2013
  • Foaming process of waste soda lime glasses by just chemical composition control of vitreous feed materials was investigated to find a novel and efficient recycling process. For the chemical composition control of feed materials, 10 wt. parts of $SiO_2$, 0.5 wt. parts of $Na_2SO_4$, 3.0 wt. parts of $B_2O_3$, and 0.3 wt. parts of carbon black as the foaming agent were mixed with 100 wt. parts of soda-lime vitreous feed powder. Proper conditions for foaming process in tunnel kiln are the foaming temperature of $830{\sim}850^{\circ}C$, the foaming time of 30~35 min, and the vitreous feed powder particle size of -325 mesh. Properties of foamed glass blocks obtained under these foaming conditions showed the density of $0.17{\sim}0.21g/cm^3$, thermal conductivity of $0.06{\pm}0.005kcal/h{\cdot}m{\cdot}^{\circ}C$, moisture absorption of 1.1~1.5%, and compressive strength of $20{\sim}30kgf/mm^2$.

Studies on the Crystallizing Glass on Low Li$_2$ O Glass (결정화 유리에 관한 연구 저 Li$_2$O 유리에 관하여)

  • 박용완;이종근;고영신;김정은
    • Journal of the Korean Ceramic Society
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    • v.13 no.1
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    • pp.30-34
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    • 1976
  • In general the chemical composition of glass ceramics in Li2O-Al2O3-SiO2 system is similar to the composition of $\beta$-spodumene (Li2O-Al2O3-4SiO2). With the object to manufacture the glass ceramics which can be produced in the domestic pot the composition of glass was so settled at 1.0 Li2O.0.9Al2O3.6.0SiO2 in order to reduce the contents of Li2O, to prevent the corrosion of the pot and to decrease the cost of raw materials. 0.2 mole and 0.1 mole of the mixture of TiO2 and ZrO2 as nucleants were added to the basic composition of 1.0 Li2O-0.9Al2O3-6.0SiO2. Each sample was divided into two kinds with a TiO2/ZrO2 ratio of 2 to 1 and the other with a TiO2/ZrO2 ratio fo 1 to 1. Thermal expansion coefficient, the most important property of glass ceramics, was tested. The softening point and the melting point of the samples were observed by the use of a heating microscope. The results obtained were as follows. The manufacturing of glass ceramics seems to be possible in the industrial plant using the domestic pot. 1) The composition of the glass which can be melted in the domestic pot process was near 1.0 Li2O.0.9Al2O3.6.0SiO2. 2) The temperature range of crystal creation and crystal growth was between 850-94$0^{\circ}C$, and 5 hours holding the samples at the temperature range was enough to crystallize them. The major crystal was $\beta$-spdumene and there existed petalite partialy. 3) The thermal expansion coefficient fo the crystallized glass was negative. 4) The deforming point of the crystallized glass was 1435$^{\circ}C$.

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