• Journal of the Korean Ceramic Society
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• v.18 no.1
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• pp.3-12
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• 1981

A glass-ceramics based on blast-furnace slag, with some additives to the theoretical composition in order to control properties of mother glass and the heat treatment conditions, has been investigated. The raw materials in this study were blast-furnace slag, serpentine, feldspar and quartz as mother glass ingredients. Titanium dioxide and chromite were used as the nucleating agents. Batch compositions of the prepared glasses and ceraming conditions were found by trial and error method. The optimum conditions were confirmed by analyzing several measured physical properties such as density change during heat treatment, microhardness of slag-ceramics prepared, viscosity change of glass at heat treatment temperatures, nucleation density change, dilatometric properties, differential thermal analysis, identification of the grown crystal and crystal sizes. The batch composition feasible to prepare slag-ceramics was 40% of blast-furnace slag, 25% of serpentine, 18% of feldspar and 17% of silica sand. Three percent titanium dioxide and 1% chromite of the mother glass were added as nucleating agents. The ceraming conditions under which the slag-ceramics having considerably good properties can be developed found as: "The glass was heated at 75$0^{\circ}C$ for 2 hours for nucleation, and the temperature was raised up to 1, 00$0^{\circ}C$ with a rate of 0.75$^{\circ}C$/min for crystal growth.owth.

• 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, $CeO_2$).

• Journal of the Korean Ceramic Society
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• v.16 no.2
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• pp.83-88
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• 1979

The Anorthite is useful compound for some ceramic industries but it is difficult to produce Anorthite because of its high melting point (1553$^{\circ}C$) and narrow firing range. On this study, glass frit was added to Anorthite batch composition to widen firing range and lower melting point. After mixing a glass frit $(Na_2O-CaO-6SiO_2)$ with Anorthite, it was melted and quenched. Ratio of Anorthite vs. glass frit was 9 : 1, 8.5 : 1.5, 8 : 2, 7.5 : 2.5, 7 : 3. In those batch composition added amount of $No_2O$ were between 1.3wt.% and 3.9wt.%. To find the thermal change of the quenched, D.T.A. was surveyed. The quenched were fired at various vitrification temperature and detected by X-Raydiffraction analysis. With addition of glass frit, firing range and vitrification temperature of Anorthite was 100~15$0^{\circ}C$ and 1050~115$0^{\circ}C$ respectively. Optimum amount of glass frit was 20wt.% for the upper mentioned.

• Fibers and Polymers
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• v.2 no.3
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• pp.141-147
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• 2001

The effect of compositions of isophorone diisocyanate (IPDl)/4.4'-diphenylmethane diisocyalate (MDI) and polypropylene oxide diol (PPG, $M_w$: 3000)/1,4-butane diol (BD) on the properties of UV-cured polyurethane acrylate films based on 2-hydroxyethyl acrylate (HEA) was examined. UV-curable polyurethane acrylates were formulated from the prepolymer. trimethylol propane triacrylate (TMPTA) as a reactive diluent, and 1-hydroxycyclohexyl ketone (Irgacure 184) as a photoinitiator. Dynamic mechanical thermal properties and elastic properties of UV-cured polyurethane acrylates was fecund to depend on the chemical composition of IPDl/MDl and PPG/BD. As the BD content increased, the tensile storage modulus of all series samples increased significantly. The storage modulus increased in the order of samples A (IPDI based samples)> samples B (IPDI/MDl (7/3 molar ratio) based samples) > samples C (IPDI/MDl (5/5 molar ratio) based samples at the same composition. Two distinct louts modulus peaks for all samples are observed owing to the softs segment glass transition temperature ($T_gh$) and hard segment glass transition temperature ($T_gh$). The difference between $T_gh$, and $T_gh$, (Δ$T_g$) increases in the order of A > B > C at the same composition. In cycle test, the initial onset strain (%) was found to decrease with increasing BD content in PPG/BD and with increasing MDI content in IPDI/MDl.

• Korean Journal of Heritage: History & Science
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• v.49 no.2
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• pp.158-171
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• 2016

The observation and analysis results of 9 glass bead samples collected from Oc Eo site in Vietnam, an outport of the ancient port city Funan in East Asia, are as follows. The type of glass beads is round, the colors are reddish brown, greenish blue, green, black and purplish blue, and the chemical composition is soda glass group. This means that they are similar in type, color and chemical compositions to glass beads from the ancient Korean peninsula. There are limitations in data because the glass beads are not from excavation investigation but from earth surface investigation. But it is significant that similar making technique and chemical composition are being observed in both the glass beads from Oc Eo and those of Korea. According to "Nihon Shoki" Kinmeiki, Baekje king sent Funan's goods and 2 slaves to Japan in 543. It is clear that there were direct or indirect exchanges between Baekje and Funan. The possibility has grown that glass beads could be included among goods.

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.96-98
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• 2004

At the previous papers, we showed that K2O-CaO-P2O5 glasses had a solubility in air so that they could be used for glass fertilizer. In this work, we fabricated the Eco-glass fertilizer containing trace elements such as B, Mg, Zn, Fe, Cu, Co, and Mo by a melt-quenching process and the dissolution properties of these glasses were investigated with pH meter and ICP analyzer. In case of the glasses containing the trace elements, effect of trace elements on the dissolutions is not obvious and ignorant the stability of mother glass. Also, the dissolution amounts of each trace elements depend on the mother glass composition and the quantity of each trace element, and mother glasses determined the dissolving velocity of chemical elements.

• Korean Journal of Materials Research
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• v.13 no.11
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• pp.732-736
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• 2003

A CP-GFRP(Carbon Powder-Glass Fiber Reinforced Plastic) sensor was fabricated for fracture detection. The electric resistance of the sensor was measured on condition of various composition of carbon powders and thickness of bundle of glass fibers. The resistance of the sensor was decreased as the increase of the content of carbon powders and the TEX of the glass fibers. In the case of loading on CP-GFRP, because inner crack was propagated, the part of percolation structures was disconnected. These observations show the following results. The conduction of CP-GFRP sensor is due to percolation structure of carbon powders and increase of resistance is due to expansion of cracks.

• Journal of the Korean Ceramic Society
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• v.30 no.5
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• pp.357-364
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• 1993

Chemical reaction occurred in the interface of Mn-Zn ferrite and glass after bonding. Effects of the formation of reaction layer on the magnetic properties were investigated. The composition of glass was 23PbO-61SiO2-6ZnO-8Na2O-2K2O and the ferrite was chosen to have a high permeability. Toroid samples of ferrites bonded with glasses, were heat-treated at $700^{\circ}C$, 80$0^{\circ}C$ and 90$0^{\circ}C$ for 1h. The reaction was observed to increase with bonding temperature, resulting in the development of reaction layer. Subsequently the initial permeability was found to be decreased. The permeabilities decreased by 25% with increasing bonding temperature from $700^{\circ}C$ to 80$0^{\circ}C$. At the bonding temperature of 90$0^{\circ}C$, the permeability was decreased by 45%, compared to that of 80$0^{\circ}C$.

• Resources Recycling
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• v.29 no.3
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• pp.51-60
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• 2020

This study was carried out to get the optimum conditions for manufacturing high refractive glass beads from waste fluorescent lamp glass. Chemical composition, X-ray diffraction pattern, particle size distribution, refractive index of glass beads, and the effect of air mixing ratio and ejection rate were investigated. The obtained results are as follows. The X-ray diffraction pattern and chemical composition of glass beads made of waste fluorescent glass are similar to common glass except ReO₂ 0.0108 wt%, BaO 0.071 wt%, NiO 0.0039 wt% and CaO 7.8 wt% but 11.7 wt% of common glass. The glass beads made of waste fluorescent lamp glass have the narrower particle size distribution of and the higher refractive index than the glass beads made of common glass. The optimal conditions of kiln operation for manufacturing glass beads from waste fluorescent lamp glass are 20 m/sec of ejection rate, 1.7 of air mixing ratio, and 940℃ of temperature.

• Applied Chemistry for Engineering
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• v.20 no.5
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• pp.557-560
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• 2009

In this study, a new wet etching method and the solution for thinning the glass with the thickness below $100{\mu}m$ were investigated. For the preparation of etching solution with low hydrofluoric acid, it was effective to use $NH_4F$ or $NH_4HF_2$ as a main ingredient with the addition of sulfuric acid or nitric acid. Influence of the composition of mixed acid solution and the temperature on the etching rate was investigated. The addition of anionic surfactant provides the function to prevent the adhesion of sludge generated by the etching reaction. A new wet etching pilot device equipped with streaming generation parts was used to test etching of commercial non-alkali glass and soda lime glass. The non-alkali glass with the thickness of 640 ${\mu}m$ and soda lime glass with the thickness of $500{\mu}m$ were etched to $45{\mu}m$ and $100{\mu}m$, respectively, by using the pilot device. After the etching by pilot device, the roughness degree of the glass surface was maintained at $0.01{\sim}0.02{\mu}m$.