• Journal of Ceramic Processing Research
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• v.13 no.spc1
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• pp.37-41
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• 2012

A lithium ion conducting borosilicate glass was fabricated by a conventional melt quenching technique from a mixture of Li2CO3, B2O3 and SiO2 powders. The Li ion conductivity of the lithium borosilicate glasses was evaluated in terms of the SiO2/B2O3 ratio. In the Li2O-B2O3-SiO2 ternary glass, the glass forming region decreases with an increasing Li2O content. At the same Li2O, the crystallization tendency of the glass samples increases with the SiO2/B2O3 ratio, resulting in a reduced glass forming region in the Li2O-B2O3-SiO2 ternary glass. The electrical conductivity moderately depends on the SiO2/B2O3 ratio in the Li2O-B2O3-SiO2 ternary glass. The conductivity of the glasses slightly increases with the SiO2/B2O3 ratio. The observed phenomenon can be explained by the modification of the glass structure as a function of the SiO2 content.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1099-1102
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• 2004

For the development of Pb-free low temperature sintering glass frits, $BaO-B_2O_3-SiO_2$ system was examined. The content of BaO and $B_2O_3$ was changed when the content of $SiO_2$ was fixed to 10 mol%. When the content of BaO was more than 60 mol% devitrification was observed. In the sintering temperature range between 520${\sim}$620 $^{\circ}C$, the optimum sintering temperature decreased as the content of BaO increased. When BaO ${\geq}$45 mol%, the glasses were crystallized after sintering. Candidate compositions are suggested in $BaO-B_2O_3-SiO_2$ system, which can replace the PbO containing glass system.

• Journal of the Korean Ceramic Society
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• v.26 no.3
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• pp.315-322
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• 1989

Li2O-Al2O3-SiO2 system glasses contained P2O5, TiO2 and ZrO2as the nucleating agents were melted and formed. The glass was subsequently heated first to nucleate and then to grow the crystals. At constant nucleating agent content the base glass compositions were varied and the influences of these variations on the crystallization behaviour were investigated. The study was made by measurement of thermal expansion coefficient, differential thermal analysis, X-ray diffraction analysis, scanning electron microscope observation and transmission measurement of crystallized glass specimen in visible region. It was shown that the content of crystalline phase decreased with increasing SiO2 content as well as decresing Li2O in the base glass compositions. As the result of X-ray diffrection analysis, the major crystal was $\beta$-quartz solid solution. The degree of crystallinity which was calculated using the noncrystalline scattering methods increased in S-shape with increasing heat treatment time. This change was similar to that in thermal expansion coefficient. The transmissions of 5mm thick samples were 80-90% in visible ray region.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.11-21
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• 1999

For microelectronic packaging application, the crystallizable glass powder in CaO-$A1_2O_3-SiO_2-B_2O_3$system was mixed with various amounts of alumina inclusions (\approx 4 $\mu \textrm{m}$), and its sintering behavior, crystallization behavior, and dielectric constant were examined in terms of vol% of alumina and the reaction between the alumina and the glass. Sintering of the CASB glass powder alone at $900^{\circ}C$ resulted in full densification (99.5%). Sintering of alumina-filled composite at $900^{\circ}C$ also resulted in a substantial denslfication higher than 97% of theoretical density, In this case, the maximum volume percent of alumina should be less than 40%. XRD analysis revealed that there was a partial dissolution of alumina into the glass. This alumina dissolution, however, did not show the particle growth and shape accommodation. Therefore, the sintering of both the pure glans and the alumina-filled composite was mainly achieved by the viscous flow and the redistribution of the glass. Alumina dissolution accelerated the crystallization initiation time at $1000^{\circ}C$ and hindered the densification of the glass. Dielectric constants of both the alumina-filled glass and the glass-ceramic composites were increased with increasing alumina content and followed rule of mixture. In case of the glass-ceramic matrix composites showed relatively lower dielectric constant than the glass matrix composite. Furthermore, as alumina content increased, crystallization behavior of the glass was changed due to the reaction between the glass and the alumina. As alumina reacted with the glass matrix, the major crystallized phase was shifted from wollastonite to gehlenite. In this system, alumina dissolution strongly depended on the particle size: When the particle size of alumina was increased to 15 $\mu\textrm{m}$, no sign of dissolution was observed and the major crystallized phase was wollastonite.

• Korean Journal of Materials Research
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• v.23 no.1
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• pp.59-66
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• 2013

Opal glass samples having different chemical compositions were synthesized and transparent glass was obtained after melting. The effects of $TiO_2$, $BaF_2$, and $CeO_2$ content on the color of the opal glass were studied by observing images of the opal samples and analyzing the results via ultraviolet visible spectroscopy and color spectrometry. The aesthetic properties of the opal glass were determined by studying the transmittance of visible light in the 400 nm to 700 nm range. The basic chemical composition of opal glass was $SiO_2$ 52.9 wt%, $Al_2O_3$ 12.35 wt%, $Na_2CO_3$ 15.08 wt%, $K_2CO_3$ 10.35 wt%, $Ca_3(PO)_4$ 4.41 wt%, $MgCO_3$ 1.844 wt%, $LiCO_3$ 2.184 wt%, and $TiO_2$ 0.882 wt%. The glass samples were prepared by varying the weight percentage of $TiO_2$, $BaF_2$, and $CeO_2$. The transmittance of visible light was decreased from 95 % to 75 % in the glass samples in which $TiO_2$ content was increased from 0 to 3.882 wt%. In the blue spectrum region, as the content of $TiO_2$ increased, the reflectance value was observed to become higher. This implies that $TiO_2$ content induces more crystal formation and has an important effect on the optical properties of the glass. The opalescence of opal samples that contained $CeO_2$ or $BaF_2$ is stronger than that in the samples containing $TiO_2$. Opal glass samples comprising $TiO_2$ had tetragonal lattice structures; samples including $CeO_2$ as an additive had cubic lattice structures (FCC, $CeO_2$).

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.1-16
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• 1990

This study was to evaluate the cytotoxic effect in vitro and the tissue response within the rat peritoneal cavity to high copper amalgam and glass ionomer-silver cement, suggested for use as a retrograde endodontic filling material. In the cytotoxicity experiment, the radioactively ($^{51}Cr$) labeled L929 mouse fibroblasts were employed to determine the relative cytotoxicity of two experimental materials. Those materials were evaluated immediately after set and after one and seven days setting. In the tissue response experiment, two experimental materials were to evaluate mean peritoneal cellular count, differential cell count and the content of silver and copper in pooled packed cells and eluate samples taken by peritoneal lavage technique, and compared with surgical control after one day. two, four and six weeks of implantation. The results were as following: 1. High copper amalgam exhibited significant cytotoxicity immediately after set but showed no sign of toxicity after one day and seven days setting materials. 2. Glass ionomer-silver cement showed no sign of toxicity immediately after set and after one day and seven days setting. 3. High copper amalgam and glass ionomer-silver cement groups produce no significant difference in the mean peritoneal cell count when compared with the surgical control group after one day, two and four weeks of implantation. Surgical control group exhibited significantly a greater cell count when compared with the High copper amalgam group after six weeks. 4. High copper amalgam group increased significantly in the percentage macrophages after four and six weeks of implantation when compared with surgical control group. 5. The trace metal analysis involved an increased silver content in the elutes and an increased copper content in the packed cells of high copper amalgam group, and an increased silver content in the packed cells and elutes of glass ionomer-silver cement group.

• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.139-144
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• 2016

The dependence of the microwave dielectric properties of the glass-ceramic composite $0.9CaMgSi_2O_6-0.1MgSiO_3$ on the crystallization behaviour was investigated as functions of the $TiO_2$ content and heat-treatment temperature. The crystallization behaviour of the specimens was evaluated via a combination of the Rietveld and reference-intensity ratio methods. For specimens with a $TiO_2$ content of up to 1 wt.%, a monoclinic diopside phase was formed, whereas a secondary $TiO_2$ phase was formed with further increases in the $TiO_2$ content. The quality factor (Qf) of the specimens was strongly dependent on the degree of crystallization. The highest Qf value was obtained with a $TiO_2$ content of 0.5 wt.%, which was improved by increasing the heat-treatment temperature. The dielectric constant (K) was affected by the size of the crystallites and the $TiO_2$ content. The temperature coefficient of the resonant frequency (TCF) was nearly constant for all of the specimens, regardless of the $TiO_2$ content or heattreatment temperature.

• Journal of Conservation Science
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• v.28 no.3
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• pp.205-216
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• 2012

65 samples of glass bead excavated from Mahan tombs of Asan Bakjimeure site consists of 13 of potash glass group and 52 of soda glass group and soda glass is superior in numbers. When classified according to color, purple blue glass bead is accompanied potash and soda glass group whereas purple glass bead is potash glass group and red, greenish blue, green and gold foil glass bead is soda glass group. Purple blue glass bead is classified as LCA type in which the content of the stabilizer is low. Of this, the soda glass categorized as LMK type with low content of MgO and $K_2O$ is determined that natron is used as the raw material. As to red glass, the homogeneous glass is LCA-B/HMK type and the heterogeneous glass is HCLA/LMK type. Thus, each of these two types are likely to be used plant ash and natron respectively. Greenish blue and green glass depends of the type that round glass is LCA-A/LMHK type and the segmented glass is LCA-B/HMK type. The gold foil glass bead is manufactured by the purity of 19.9~22.6K gold foil and the soda glass of HCLA/LMK type. In other words, the most of the glass bead of Asan Bakjimeure site is similar to the composition of the glass confirmed in other sites of the Baekche period. On the other hand, the greenish blue and green segmented bead and some red round bead is a different chemical composition is considered that the difference in raw materials. These characteristics is expected to be an important evidence for the understanding of the trade system of the ancient glass.

• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.160-164
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• 1995

Mechanical and chemical tests were performed on $Zro_2 \cdot SiO_2$ glass fibers manufactured by the sol-gel method and E-glass fibers-reinforced cement composites in order to investigate the interactions between glass fibers and cement matrices. Chemical attack leads to corrosion of the glass fiber surfaces. In the corrosion reactions, the surface of $30ZrO_2 \cdot 70 SiO_2$ glass fibers developed a densified concentric layer, which consists of glass corrosion products with much higher Zr and lower Si than the fresh glass fiber. The layer of reaction product is regarded to stiffen the cement matrices and provide a useful improvement to the mechanical properties. The addition of $ZrO_2$ content increases the corrosion resistance of glass fibers in cement by forming a passivating layer on the surface of glass fibers.

• Journal of the Korea Concrete Institute
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• v.14 no.6
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• pp.1032-1039
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• 2002

Since recycling waste glass as a material for concrete has a great advantage environmentally and economically, the US, Japan and other countries have started recycling waste glass widely and accumulating the technology of manufacturing equipment and its construction. However, there is no practical data on the mechanical property of concrete using waste glass. In this study, the mechanical property of the steel fiber reinforced concrete using waste glass was analyzed in terms of waste glass content(20vo1. ％, 40vo1. ％ as a part of fine aggregate) and steel fiber content(0.5~ 1.5vol.％). The results of this study are as follows : The workability of the concrete including steel fiber and waste glass decreases, as the inclusion rate of waste glass and steel fiber increases. The tensile strength, flexural strength and flexural toughness of the concrete including waste glass increase considerably, as the inclusion rate of steel fiber increases. From the results, the appropriate inclusion rate of steel fiber and waste glass is thought to be 1.0vol. % and 20vo1. ％, respectively.