• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.583-588
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• 1990

Glass films in the binary system B2O3-SiO2 and Al2O3-SiO2 were prepared on soda-lime-silica slide glass by the dip-coating technique from TEOS and boric acid or aluminum nitrate. Thickness of the films varying with viscosity and withdrawal speed were measured and effect of composition and firing temperature on the properties such as transmittance and refractive index were investigated. nM2O3.(100-n)SiO2(M=B or Al) films containing up to 20mol% B2O3 and 40mol% Al2O3 were transparent. Maximum transmittance at visible range were obtained for the sample containing 15mol% Ba2O3 and 32.5mol% Al2O3 and heat-treated at 50$0^{\circ}C$, respectively. Refractive index of the film containing 15mol% B2O3 was mininum in the B2O3-SiO2 binary system and minimal refractive index was appeared at the film containing 32.5mol% Al2O3. In IP spectra, addition of B2O3 were increased absorption peak intensity of B-O and Si-O-B bond and addition of Al2O3 were decreased absorption peak intensity of Si-O bond, respectively.

• 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.

• Journal of the Korean Ceramic Society
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• v.11 no.3
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• pp.19-26
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• 1974

Mechanical properties of the system PbO-B2O3-V2O5 low melting glass during crystallization by heat-treatment were investigated. Wettability of the system PbO-B2O3-V2O5 was excellent and appropriate for commercial sealing as a low melting solder glass. Crystals, during heat-treated at 30$0^{\circ}C$ of the system PbO-B2O3-V2O5 were $\beta$-4PbO.B2O3, 5PbO.4B2O3, and Pb2V2O7 mainly. The percent of crystallinity was 82$\pm$5%. Mechanical properties of the system PbO-B2O3-V2O5 were influenced not only by the differences of density and coefficient of thermal expansion and the stress induced from the difference in the density and coefficient of thermal expansion between glass phase and crystals but also crystallization conditions.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.123-128
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• 2004

Both photoluminescence and the long-phosphorescent properties for $SrAl_2O_4$ : Eu$^{+2}$, $Dy^{+3}$ phosphor powder synthesized by the solid phase reaction were investigated as a function of $B_2O_3$ composition (0-10 wt%). The highest emission wavelength (520nm) of photoluminescence spectra was not affected by $B_2O_3$concentration. The highest emission intensity was obtained by the concentration of 3 wt% $B_2O_3$.After the removal of the Xenon lamp excitation (360nm), also, the excellent long-phosphorescent property of the phosphors was obtained by the concentration of 3 wt% $B_2O_3$ although the decay times for all phosphors decreased exponentially.

• Membrane Journal
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• v.25 no.2
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• pp.115-122
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• 2015

$SiO_2{\cdot}B_2O_3$ was prepared by trimethylborate (TMB)/tetraethylorthosilicate (TEOS) mole ratio 0.01 at $800^{\circ}C$. PDMS[poly(dimethysiloxane)]-$SiO_2{\cdot}B_2O_3$ composite membranes were prepared by adding porous $SiO_2{\cdot}B_2O_3$ to PDMS. To investigate the characteristics of PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane, we observed PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane using TG-DTA, FT-IR, BET, X-ray, and SEM. PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was studied on the permeabilities of $H_2$ and $N_2$ and the selectivity ($H_2/N_2$). Following the results of TG-DTA, BET, X-ray, FT-IR, $SiO_2{\cdot}B_2O_3$ was the amorphous porous $SiO_2{\cdot}B_2O_3$ with $247.6868m^2/g$ surface area and $37.7821{\AA}$ the mean of pore diameter. According to the TGA measurements, the thermal stability of PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was enhanced by inserting $SiO_2{\cdot}B_2O_3$. SEM observation showed that the size of dispersed $SiO_2{\cdot}B_2O_3$ in the PDMS-$SiO_2{\cdot}B_2O_3$ composite membrane was about $1{\mu}m$. The increasing of $SiO_2{\cdot}B_2O_3$ content in PDMS leaded the following results in the gas permeation experiment: the permeability of both $H_2$ and $N_2$ was increased, and the permeability of $H_2$ was higher than $N_2$, but the selectivity($H_2/N_2$) was decreased.

• Journal of the Korean Ceramic Society
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• v.36 no.7
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• pp.767-772
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• 1999

The effect of B2O3 addition on the sintering behavior dielectric and ferroelectric properties of Ba0.7Sr0.3TiO3 ceramics were investigated. The sample with 0.5wt% B2O3 was sintered under 115$0^{\circ}C$. The dielectric and ferroelectric properties of BST with 0.5wt% B2O3 was as good as BST without B2O3 sintered at 135$0^{\circ}C$ and its dielectric loss was even better When B2O3 was added over 1.0wt% the overdoped B2O3 remained in the specimens and formed a second phase which degraded the sintering behaivor dielectric properties of BST.

• Journal of the Korean Ceramic Society
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• v.50 no.1
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• pp.57-62
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• 2013

We investigated the thermal and electrical properties of the $B_2O_3-ZnO-Bi_2O_3$ glass system as a sealing material in sheath heater modules. A composition with over 90 wt% $Bi_2O_3$ in the $B_2O_3-ZnO-Bi_2O_3$ system was glassified by controlling the cooling rate. The glass transition temperature and thermal expansion coefficient in bismate glass could be controlled by the minor ingredients of ZnO, $SiO_2$, $BaO_2$, and $K_2O$. The $B_2O_3-ZnO-Bi_2O_3$ glass system bonded well to metal, and bismate glass insulating properties were comparable to those of bismate glass $B_2O_3-ZnO-PbO$ glass system in a sheath heater module.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.1
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• pp.7-10
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• 2003

Quarternary $SrO-B_2O_3-Al_2O_3-SiO_2$ glasses were fabricated as a function of $R({\equiv}SrO\;mole%/B_2O_3\;mole%)$ and $K({\equiv}(Al_2O_3+SiO_2)\;mole%/B_2O_3\;mole%)$. The structures of these glasses were investigated through Infrared absorption spectra. When R increased, the intensities of the absorption bands around $1,200{\sim}1,600cm^{-1}$ resulting from the B-O stretching vibration bond in the symmetrical trigonal $BO_3$ units decreased, and these of the absorption bands around $800{\sim}1,200cm^{-1}$ caused by the B-O stretching vibration bond of the tetrahedral $BO_4$ units varied. Also, the intensities of the absorption bands for the B-O stretching vibration band in trigonal $BO_3$ units increased and these of the bands for B-O stretching vibration bond in tetrahedral $BO_4$ units decreased as K increased.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.1
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• pp.61-66
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• 2005

$^{11}B MAS NMR$ spectra of binary glass system $xV_2O5-B_2O_3$ and ternary glass system $xV_2O5-B_2O_3-yNa_2O$ (x = $V_2O_5 mol%/$B_2O_3$ mol%, y = $Na_2O$ mol$/$B_2O_3$ mol%) were acquired. $BO_3$ units are dominant components in the spectra of $xV_2O_5-B_2O_3$glass systems while both $BO_3$ and $BO_4$ unit appear in comparable amounts in the spectra of $xV_2O_5-B_2O_3-yNa_2O$ glass systems. More $BO_3$ units were monitored for higher $V_2O_5$ contents while more $BO_4$ unit for higher $Na_2O$ contents. Quadrupole parameters such as $e^2qQ$ and $\eta$ obtained form spectral simulation indicate that $e^2qQ$ has a maximum value at x = y 1 and $\eta$ decreases and increases as x or y grows, respectively. Our results suggest that $V_2O_5$ and $Na_2O$ play opposite roles in the ternary glasses.

• Membrane Journal
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• v.14 no.4
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• pp.312-319
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• 2004

The porous SiO$_2$-B$_2$O$_3$ membrane was prepared from Si(OC$_2$$H_5$)$_4$-($CH_3$O)$_3$B-C$_2$$H_5$OH-$H_2O$ system by sol-gel method. In order to investigate the characteristics of this membrane, we examined that using BET, IR spectrophotometer, X-ray diffractometer, SEM and TEM. At $700^{\circ}C$, the surface area of SiO$_2$-B$_2$O$_3$ membrane was 354.398 $m^2$/, the median pore diameter was 0.0048 ${\mu}{\textrm}{m}$, and the particle size of SiO$_2$-B$_2$O$_3$ membrane was 7 nm. The separation properties of the gas mixture ($H_2$/$N_2$) through the SiO$_2$-B$_2$O$_3$ membrane was studied as a function of pressure. The real separation factor($\alpha$) of SiO$_2$-B$_2$O$_3$ membrane for $H_2$/$N_2$ gas mixture was 4.68 at 155.15 cmHg and $25^{\circ}C$. The real separation factor($\alpha$), head separation factor($\beta$) and tail separation factor((equation omitted)) were increased as the pressure of permeation cell increased.