• Journal of the Korean Ceramic Society
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• v.12 no.2
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• pp.26-30
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• 1975

The experiment has been carried out to clarify the condition of acid treatment for preventing the crack formation caused by swelling and shrinking during acid leaching process. The borosilicate glass contained phosphorous pentoxide was chosen as the sample, which is recognized to be more homogeneous in phase separation. The various effects, such as kind, cocentration and acid temperature, were investigated. The experimental results are summerized as follows. (1) Sulfuric acid is more stable than hydrochrolic acid for preventing the crack. (2) The optimum concentration of acid lies in the range of 0.1~0.3N. (3) Higher temperature of the acid to treat the separated glass was more stable than lower temperature. (4) The rate of crack decreased with the longer period and the higher temperature of the heat treatment.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1642-1644
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• 1996

Passivation must prevent ionic charge movement on the surface of the junction, thereby minimizing the junction leakage and maximizing the breakdown voltage of the devices. Borosilicate glasses are widely used as surface passivants for such silicon power devices as thyristors, transistor, and diodes. Since these 91asses are electrically stable at high temperatures and in high electric fields, they can readily be applied as a thick film, and they are resistant to humidity and have low ionic mobility. A deposition technique of glass film on the silicon surface by electrophoresis in which acetone is used as a suspension medium has been investigated. The purpose of this paper is to describe electrophoretic deposition method for glass passivation and characteristics of glass films which were compared using DTA, SEM, XRD, as a function of firing temperature.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.182-185
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• 2005

Indentation pattern and line pattern were machined on borosilicate(Pyrex 7740 glass) surface using the combination of mechanical machining by $Nanoi-indenter\circledR$ XP and HF wet etching, and a etch-mask effect of the affected layer of the nano-scratched and indented Pyrex 7740 glass surface was investigated. In this study, effects of indentation and scratch process with etching time on the morphologies of the indented and scratched surfaces after isotropic etching were investigated from an angle of deformation energies.

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.696-699
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• 1996

Silicate and borosilicate gels were prepared by the sol-gel process and thermally treated in the 150-850 ℃ temperature range. Solid-state 1H MAS and 29Si CP/MAS NMR spectroscopy were used to investigate the effects of heat treatments on the silicate gel to glass conversion process. The 1H NMR isotropic chemical shifts and the relative intensities of hydrogen bonded and isolated silanol groups have been used to access the information concerning the dehydration process on the silicate gel surface. The 29Si NMR isotropic chemical shifts affected by the local silicon environment have been used to determine the degree of crosslinking, i.e. the number of siloxane bonds. These NMR results suggest that the silicate gel to glass conversion process is occurred by two stages which are dependent on the temperature; (1) the formation of particles up to 450 ℃ and (2) the formation of large particles by aggregation of each separated single particle above 450 ℃. In addition, the effects of B atom on the formation of borosiloxane bonds in borosilicates have been discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.342-342
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• 2008

The low temperature sintering and microwave dielectric properties of ceramic/glass composites which were composed of ceramics in the $Bi_2(Zn_{1/3}Nb_{2/3})_2O_7$ and zinc borosilicate glass/bismuth-zinc borosilicate glass were investigated with a view to applying the microwave dielectrics to low temperature co-fired ceramics. The $Bi_2(Zn_{1/3}Nb_{2/3})_2O_7$ addition of 5 wt% ZBS and BZBS glass ensured a successful sintering below $900^{\circ}C$. In addition, pyrochlore phase was observed in the all composition. $Bi_2(Zn_{1/3}Nb_{2/3})_2O_7$ with 5 wt% BZBS glasss demonstrated 70 as the dielectric constant ($\varepsilon_r$), 2,500 GHz as the Q$\times$f value, and -40 ppm/$^{\circ}C$ as TCF.

• The Korean Journal of Ceramics
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• v.1 no.3
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• pp.155-159
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• 1995

Borosilicate, $B_2O_3$ and BN derived from liquid precursors have been tested as shielding materials for the long period of oxidation resistance of C/BN composites at $650^{\circ}C$. Borosilicate coating displayed excellent oxidation resistance and low moisture absorbance, while $B_2O_3$ and BN were less effective in elevating the oxidation resistance. The enhancement of the oxidation resistance was explained as self-healing effect by viscous flow of the borosilicate glass over Tg, resulting in the reduction of the exposed carbon fibers in a BN matrix.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.266-269
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• 2003

To understand the long-term leach behavior of a borosilicate waste glass in a repository, the leaching experiment with three kinds of simulated borosilicate waste glasses has been carried out since the middle of 1997. The five years results indicate that a boron would be applied as an indicator of a long-term leaching of their borosilicate waste glasses and that their long-term leach rates have a tendency to be close to about $0.03g/m^2-day$ even though their compositions and their ratios of the surface area to the volume of leachate are different.

• Nuclear Engineering and Technology
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• v.49 no.1
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• pp.216-223
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• 2017

In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and $10^{th}$ value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

• Journal of the Korean Ceramic Society
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• v.18 no.1
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• pp.27-34
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• 1981

The phase separation of low-alkali borosilicate glass with the composition of $6.25Na_2O$.$18.75B_2O_3$.$75.00SiO_2$(mole%) substituting $Li_2O$ for $Na_2O$ was studied. The phase separation in the temperature range of transformation was examined with various heating temperatures and soaking times. Durability to water, thermal expansion and specific density of the specimen were investigated and the microstructure of the separated phase was also observed by transmission electron micrograph techniques. The maximum alkali extraction result with the best phase separation effect was obtained when $Na_2O$ of the base glass was replaced with $1.88Li_2O$ (mole %) and electron micrograph of carbon film replica of $1.88Li_2O$$4.37Na_2O$.$18.75B_2O_3$.$75.00SiO_2$ (mole %) glass showed that the glass consisted of homogeneous two phases. The minimum specific density was shown with the specimen treated at 57$0^{\circ}C$ and it was also shown that the longer the treating time the lower the specific density. The apparent activation energies of approximately 45 kcal/mole by the alkali extraction and 43kcal/mole by the thermal expansion method were derived from the Arrhenius plots, respectively.

• Membrane Journal
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• v.25 no.2
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• pp.123-131
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• 2015

The PTMSP/PDMS graft copolymer were synthesized from the PTMSP[poly(1-trimethylsilyl-1-propyne)] and the PDMS[poly(dimethylsiloxane)] and then the PTMSP/PDMS-borosilicate composite membranes were prepared by adding the porous borosilicates to the PTMSP/PDMS graft copolymer. The number-average molecular weight (${\bar{M}}_n$) and the weight-average molecular weight (${\bar{M}}_w$) of PTMSP/PDMS graft copolymer were 460,000 and 570,000 respectively, and glass transition temperature ($T_g$) of PTMSP/PDMS graft copolymer appeared at $33.53^{\circ}C$ according to DSC analysis. According to the TGA measurements, the addition of borosilicate to the PTMSP/PDMS graft copolymer leaded the decreased weight loss and the completed weight loss temperature went down. SEM observation showed that borosilicate was dispersed in the PTMSP/PDMS-borosilicate composite membranes with the size of $1{\sim}5{\mu}m$. Gas permeation experiment indicated that the addition of borosilicate to PTMSP/PDMS graft copolymer resulted in the increase in free volume, cavity and porosity resulting in the gradual shift of the mechanism of the gas permeation from solution diffusion to molecular sieving surface diffusion, and Knudsen diffusion. Consequently, the permeability of $H_2$ and $N_2$ increased and selectivity ($H_2/N_2$) decreased as the contents of borosilicate increased.