• Journal of Surface Science and Engineering
• /
• v.48 no.1
• /
• pp.1-6
• /
• 2015

Amino-carboxyl acid as a complexing agent in acid copper sulfate solution was utilized to improve the adhesion of immersion copper layer for steel wire. According to the tape test results, regardless of alloy composition of the wire, the adhesion of immersion copper layer was improved with the addition of amino-carboxyl acid. The incorporation of H and Fe in the plating layer was analyzed by TOF-SIMS. The H and Fe were detected at the entire coating layer without any addition of amino-carboxyl acid. However, with addition of amino-carboxyl acid, the H and Fe were scarcely detected at the coating layer.

• YAKHAK HOEJI
• /
• v.45 no.1
• /
• pp.46-54
• /
• 2001

Protein carboxyl Ο-methylation is a kind of enzymatic reaction producing carboxyl methylester catalyzed by protein carboxyl Ο-methyltransferases at the carboxyl group of amino acid residues in polypeptide. Since the finding of carboxyl methylesterl many studies have been focused on the under-standing of biological functions in eukaryotes but still not clear except for roles in Ras attachment to membrane and protein repair. In this study, we investigated the protein carboxyl methylation in porcine liver and testis in respect of identification and characterization of carboxyl methylesters and natural proteinous substrates using pH stability of the esters and electrophoresis under acidic and basic conditions. We detected several kinds of methyl esters, 3 kinds each in cytosolic fractions from liver and testis. Under the treatment of strong acid and base, the ratio between base-stable substrates and unstable ones in liver (4 : 6) was different from the ratio obtained in testis (6 : 4). The methyl accepting capacities were affected by enzymatic proteolysis between the range of 55 to 65% in liver and of 35 to 45% in testis. Separation of the methylated proteins by acidic electrophoresis in the presence of urea and SDS revealed distinctively natural substrates of 26, 33 and 80 kD in the cytosol from liver and of 14, 25, 32 and 86 kD from testis. Most of the labelling, however were lost following electrophoresis under moderate alkaline condition, except for molecules of newly detected 7 and 17 kD in livers and 15, 29, 40 and 80 kD in testis. From these results, it was proposed that protein carboxyl Ο-methylation in each organs may be catalyzed by different classes of protein carboxyl Ο-methyltransferases. In addition, it is suggested that the protein carboxyl methylation in liver and testis may have different patterns in respect of natural substrates.

• Bulletin of the Korean Chemical Society
• /
• v.16 no.7
• /
• pp.672-674
• /
• 1995

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.1
• /
• pp.38-49
• /
• 1985

The water soluble organic fractions (WSOF) from an agricultural soil (W), a soil treated with sludge for 6 years ($WS_6$), a sludge-soil mixture incubated for one week ($WS_1$), and sewage sludge (SS) were extracted, purified, and characterized by elemental analysis, functional group determinations, infrared, UV-visible, and proton nuclear magnetic resonance spectrosocpy. The SS was characterized by higher organic H, N, and P contents, a higher H/C ratio, and a lower C/N ratio than W. Total acidity carboxyl and phenolic hydroxyl group contents were generally highest in SS, intermediate in $WS_6$ and $WS_1$, and lowest in W. Overall aromatic character and aromatic carboxyl group contents were highest in W, and lowest in SS. Aliphatic proton, aliphatic carboxyl, and phenolic hydroxyl group contents were highest in SS, and lowest in W. Protein decomposition products were the pronounced components in SS, and decreased in concentration as the sludge component in the mixtures decreased. The $^1H$-NMR spectra suggested that the SS-protons were bound to a wider range of functional groups than W-protons. Structural complexities around the aromatic protons followed the following order: SS>$WS_1$>$WS_6$>W.

• Polymer(Korea)
• /
• v.31 no.4
• /
• pp.335-342
• /
• 2007

The goal of this study is to investigate the effect of molecular structure modifications on the kinetics of physical aging of thin films formed from 6FDA-based polyimides with time. The permeability for 6FDA-based polyimide thin films containing carboxyl acid groups commonly decreased 20-50% after the isothermal aging and the selectivity gained anywhere from 10% to 30% while the rate of permeability loss on the change of polymer structure showed different reciprocal relationship between 6FDA-6FpDA based polyimides and 6FDA-DAM based polyimides. The Lorenz-Lorentz equation was used to relate changes in refractive index to densification and volume relaxation with aging time. The permeability as a function of aging time fits the expected form $P=Ae^{(-B/f)}$. The results matched well with the data for different polymer membranes.

• Journal of the Korean Chemical Society
• /
• v.39 no.3
• /
• pp.213-217
• /
• 1995

Infrared Spectra of aqueous solution of BUDDA(Butyldithiodiacetic acid), BMDDA(Benzmethyldithiodiacetic acid), and CHDDA(Cyclohexyldithiodiacetic acid) are reported at various pH values. On the basis of the antisymmetric stretching bands of the ionized and un-ionized carboxyl group, the structures of the free-ligand are inferred. An approach to the study of these structures are compared with the results of potentiometric titration curve and IR Spectra studies.

• Journal of the Korean Ceramic Society
• /
• v.48 no.6
• /
• pp.510-515
• /
• 2011

In this study, as a material used to replace silica fumes for high strength concrete, nano-silica compound with organic functional group for dispersion and with inorganic silica group that can cause a pozzolan reaction is synthesized, These nano silica compound is divided into IC, which is nano size $SiO_2$ with irregularly combined hydroxyl group and carboxyl group, and RC, which is nano size $SiO_2$ with regularly combined hydroxyl group and carboxyl group. The effects of these nano silica compound on the hydration of cement are reviewed. As a result, all of synthesized nano-silica compounds have excellent dispersion on the cement flow, we think that dispersion property is the effect of air entraining by synthesized nano-silica compounds. The result of the microstructure observation showed that the particle size of the synthesized nano-silica is smaller than silica fume and spread evenly among the cement particles. In initial The phenomenon of strength decreasing occurred due to delayed hydration reaction by the synthesized nano-silica with carboxyl(-COOH) and hydroxyl(-OH) functional group.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2006.06b
• /
• pp.265-270
• /
• 2006

This paper reports an improved headspace gas chromatographic method for the determination of carboxyl group content in wood fibers. Pretreatment of wood fibers was applied using dilute HCl to convert carboxyl groups to carboxylic acid groups and then using deionized water to wash fiber samples thoroughly. The samples were finally air dried. Sodium bicarbonate solution was used to react with carboxylic acid groups of the pretreated fibers in a closed testing vial to release carbon dioxide. The content of carboxyl groups in fibers was accurately quantified by determining the amount of carbon dioxide released by a headspace gas chromatograph equipped with a thermal conductivity detector. The modified process for fiber sample pretreatment increased the reliability and accuracy in measuring carboxylic acid groups. The present method is simple, accurate.

• Elastomers and Composites
• /
• v.48 no.3
• /
• pp.225-231
• /
• 2013

In this study, we observed the effect of carboxylated SBR latex and zinc oxide on styrene-butadiene-styrene( SBS) composites for improving abrasion and debris. SBS composite, which added only silica, showed poor mechanical properties, NBS abrasion, and debris, caused by strong filler-filler interaction of silica. In case of adding carboxylated SBR latex, mechanical properties, NBS abrasion and debris of SBS composite were improved. Because of carboxyl group of carboxylated SBR latex interacted with silanol group of silica. Both carboxylated SBR latex and zinc oxide were added, SBS composite showed highest mechanical properties, NBS abrasion, and debris by forming ion cluster between carboxylated SBR latex and zinc oxide. By FT-IR analysis, ion clusters were confirmed that observed zinc carboxylated group stretch peak at $1550{\sim}1650cm^{-1}$ range. SBS composite, SC-4, showed excellent mechanical properties ; tensile strength $156kgf/cm^2$, elongation 936%, tear strength 59.4kgf/cm ; and excellent abrasion characteristics ; NBS abrasion 338%. Also, debris of SC-4 was minimized and showed wave-shape in fracture surface.

• Textile Coloration and Finishing
• /
• v.15 no.4
• /
• pp.17-23
• /
• 2003

Fourier transform infrared spectroscopy(FT-IR) was used to characterize the intermolecular ester crosslinkages in cotton cellulose. The FT-IR data show that the band of the ester carbonyl group can be separated from overlapping carboxyl/carbonyl band by converting carboxyl group to carboxylate. When esterification occurs between a polycarboxylic acid and cotton cellulose, the carbonyl groups retained in the cotton exist in three forms; ester, carboxyl, and carboxylate anion. The FT-IR data were also correlated to the durable press rating result obtained. The appearance of BTCA-finished durable press silk/cotton fabrics were improved.