• 한국세라믹학회지
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• 제31권5호
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• pp.499-504
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• 1994

PbTiO3 thin films were prepared by sol-gel spin coating method using metal alkoxide and diethanolamine (DEA). The precipitation of the PbTiO3 sol occurred at pH 7.3 with HNO3 addition, regardless of the amount of DEA. The gelation time of the PbTiO3 sol was reduced with increasing amount of HNO3 and/or water. When the PbTiO3 films prepared by 0.2 molar coating solution were annealed at $650^{\circ}C$ for 30 min, dense and single phase perovskite films were obtained. Dielectric constant and loss tangent of the film were 239 and 0.01 at 1 kHz, respectively.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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• pp.217-222
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• 2004

This study was conducted to estimate if the level of several chemical ingredients including alkanolamines or ethanolamines (EA) examined in the specific synthetic metalworking fluid (MWF) ‘A’ can cause anti-microbial activity and health effect. Three water-based MWF products (‘A’, ‘B’, and ‘C’) were studied every week for two months. Chemical ingredients such as formaldehyde, boron, EA, and copper were examined. In the sump where MWF ‘A’ was used, not only the total level of EA, monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA), but also boron level were significantly higher than those of the other MWFs. ANOVA statistical tests indicated that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF ‘A’ were significantly higher than those in other MWF types. Correlation tests also found that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF ‘A’ are significantly correlated. We suggested the assumptions that excessive concentrations of EA, and borate at a high pH level, may cause anti-microbial resistance synergically. To demonstrate this assumption, additional study is needed to examine the relationship between the levels of microbes and excessive concentrations of EA, and borate at a high pH level.

• KSTLE International Journal
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• 제4권2호
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• pp.52-55
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• 2003

This study was conducted to estimate if the level of several chemical ingredients including alkanolamines or ethanolamines (EA) examined in the specific synthetic metalworking fluid (MWF) "A" can cause anti-microbial activity and health effect. Three water-based MWF products ("A", "B", and "C") were studied every week for two months (from June 1, 2002 to July 30, 2002). Chemical ingredients such as formaldehyde, boron, EA, and copper were examined. In the sump where MWF "A" was used, not only the total level of EA, monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA), but also boron level were significantly higher than those of the other MWFs. ANOVA statistical tests indicated that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF "A" were significantly higher than those in other MWF types. Correlation tests also found that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF "A" are significantly correlated. We suggested the assumptions that excessive concentrations of EA, and borate at a high pH level, may cause anti-microbial resistance synergically. To demonstrate this assumption, additional study is needed to examine the relationship between the levels of microbes and excessive concentrations of EA, and borate at a high pH level.

• 한국환경과학회지
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• 제12권5호
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• pp.551-557
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• 2003

An experimental study of the absorption of CS$_{2}$ in the secondary amine diethanolamine(DEA) was performed in this work. The primary objectives were to investigate an analogy between N2O and CS$_{2}$ permitting estimation of the physical solubility and diffusivity of the sulfur gases in the reacting amino solutions. The solubilities of CS$_{2}$ in water at 25, 40 and 6$0^{\circ}C$ has been measured. The data show fair agreement with previous literature values. The solubility of CS$_{2}$ in 5-25 weight % polyethylene glycol has been measured in order to investigate a possible analogy between CS$_{2}$ and N$_{2}$O The diffusivities of CS$_{2}$ in water and the reaction rate between CS$_{2}$ and DEA has been measured at 25 and 4$0^{\circ}C$, using a wetted sphere apparatus operated at approximately 1/3 atmospheres pressure, which is a previously untried method.

• 한국세라믹학회지
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• 제42권6호
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• pp.432-436
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• 2005

Nickel powders synthesized by the reduction of hydrazine of nickel salts fiom diethanolamine(DEA) solution, and investigated the morphological characteristics of nickel powders with the addition of hydrazine, reaction temperature, the composition of mixed solvents. The addition of hydrazine in DEA solution largely affected on size control of nickel powders. Under $N_2H_4/Ni^{2+}$ molar ratio= 1.5 and 2.0 conditions, spherical nickel powders in the submicron range obtained, owing to higher the reduction rate. An increase of temperature increased the size of nickel particles. At $220^{\circ}C$ for 40 min, the nickel powders composed of polyhedral particles with high crystalline in the submicron range. The mixed volume ratio of TEA to DEA affected on the increase of particle size and the inhibition of agglomerate between particles.

• 한국환경과학회지
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• 제26권1호
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• pp.79-85
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• 2017

Multi-Walled Carbon Nanotubes (MWCNTs) were modified with epoxy and aminosilane diethanolamine (DEA), and nanocomposites of poly(butylene adipate-co-terephthalate) (PBAT) and the modified MWCNTs were prepared with the aim of improving the physical properties of biodegradable PBAT. The physical and the thermal properties of the PBAT/MWCNT nanocomposites were investigated using various techniques. Fourier transform infrared spectroscopy measurements revealed that the MWCNTs were efficiently modified with DEA. Scanning electron micrographs of the nanocomposites indicated that the modified MWCNTs were dispersed homogeneously in PBAT. The thermal stability of the nanocomposite decreased with increase in the content of epoxy-MWCNT-DEA due to the poor thermal stabilities of epoxy and amino silane DEA. However, the surface hydrophobicity of the nanocomposite increased. The highest stress (170% of PBAT) was observed when the content of epoxy-MWCNT-DEA in the nanocomposite was 2 wt%.

• Safety and Health at Work
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• 제1권2호
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• pp.175-182
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• 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group ($HOCH_2CH_2$), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from $0.19\;mg/m^2{\cdot}min$ at $23.5^{\circ}C$ to $8.04\;mg/m^2{\cdot}min$ at $60^{\circ}C$. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was $0.45\;mg/m^3$ in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2003년도 Challenges and Achievements in Environmental Health
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• pp.213-216
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• 2003

This study was conducted to estimate if the level of several chemical ingredients including alkanolamines or ethanolamines (EA) examined in the specific synthetic metalworking fluid (MWF) “A” can cause anti-microbial activity and health effect. Three water-based MWF products (“A”, “B”, and “C”) were studied every week for two months (from June 1, 2002 to July 30, 2002). Chemical ingredients such as formaldehyde, boron, EA, and copper were examined. In the sump where MWF “A” was used, not only the total level of EA, monoethanolamine(MEA), diethanolamine(DEA) and triethanolamine(TEA), but also boron level were significantly higher than those of the other MWFs. ANOVA statistical tests indicated that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF A were significantly higher than those in other MWF types. Correlation tests also found that levels of pH, alkalinity, boron, MEA, DEA and TEA in MWF “A” are significantly correlated. We suggested the assumptions that excessive concentrations of EA, and borate at a high pH level, may cause anti-microbial resistance synergically, To demonstrate this assumption, additional study is needed to examine the relationship between the levels of microbes and excessive concentrations of EA, and borate at a high pH level.

• 한국세라믹학회지
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• 제29권4호
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• pp.328-334
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• 1992

TiO2 sols were prepared by hydrolysis and polymerization of titanium tetra-isopropoxide (TTIP) in the presence of diethanolamine (DEA). The optimal mole ratio of water to TTIP is 2 and the concentration of the TiO2 sol 0.7 M. Golden TiN films without cracks were obtained by dipping Si(110) wafers into the TiO2 sol and followed by nitridation in NH3 at 1100$^{\circ}C$ for 5 h. The TiN films were studied by an optical microscope, DTA, TGA and X-ray analysis.

• 한국산업보건학회지
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• 제15권3호
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• pp.270-276
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• 2005

This study was conducted to examine whether a specific synthetic metalworking fluid (MWF), "A", in use for 10 months without replacement, displayed microbial resistance and to identify the additives associated with the control of microbial growth. Three synthetic MWF products ("A", "B", and "C") were studied every week for two months. Microbial deterioration of the fluids was assessed through evaluation by endotoxin, bacteria and fungi levels in the MWFs. In addition, formaldehyde, boron, ethanolamine, and copper levels were also studied to determine whether they influence microbial growth in water-based MWFs. Throughout the entire study in the sump where MWF "A" was used, bacteria counts were lower than 103 CFU/mL, and endotoxins never exceeded 103 EU/mL. These levels were significantly lower than levels observed in sumps badly deteriorated with microbes. Boron levels in MWF "A" ranged from 91.7 to 129.6 ppm, which was significantly higher than boron levels found in other MWF products. The total level of ethanolamine (EA) in MWF "A" ranged from 35,595 to 57,857 ppm (average 40,903 ppm), which was over ten times higher than that found in other MWFs. Monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA) concentrations in MWF "A" were also significantly higher than seen in other MWFs. However, although EA and boron might improve anti-microbial performance, their abuse can pose a serious risk to workers who handle MWFs. From an industrial hygiene perspective, our study results stress that the positive synergistic effect of boron and EA in reducing microbial activity in MWF must be balanced with the potentially negative health effects of such additives. Our study also addresses the disadvantage of failing to comprehensively report MWF additives on Material Safety Data Sheets (MSDS). Future research in MWF formulation is needed to find the best level of EA and boron for achieving optimal synergistic anti-microbial effects while minimizing employee health hazards.