• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.16-23
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• 1991

Resins of polystyrene supported triethylenetetramine of linear and claw types have been prepared by the reaction of triethylenetetramine with chloromethylated polystyrene. The resin supported triethylenetetramines were principally characterized by infrared spectra. Kinetics of adsorption of transition metals on the resin have been investigated. This paper reports the results of the diffusion coefficients and entropies of activation. The rate determining step is a process of diffussion through the particle.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.70-73
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• 2005

• Bulletin of the Korean Chemical Society
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• v.9 no.4
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• pp.262-264
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• 1988

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2385-2390
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• 2011

Preparation of ammonium dihydrogenphosphate supported on alumina ($NH_4H_2PO_4/Al_2O_3$) and its primary application as a solid acid supported heterogeneous catalyst to the synthesis of 1,2,4,5-tetrasubstituted imidazoles by a one-pot, four-component condensation of benzil, aromatic aldehydes, primary amines, and ammonium acetate under thermal solvent-free conditions were described. The results showed that the novel catalyst has high activity and the desired products were obtained in high yields. Furthermore, the products could be separated simply from the catalyst, and the catalyst could be recycled and reused with only slight reduction in its catalytic activity. Characterization of the catalyst was performed by FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1409-1412
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• 2014

Sex hormones are important metabolites in vertebrates' development and reproduction. For rapid screening sex hormones, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is one of the promising analytical platforms, but MALDI MS faces many challenges in detecting steroids such as low ionization efficiency and matrix background interference. One potential strategy to overcome matrix interference in the low m/z region is using a cyclodextrin (CD)-supported matrix for steroid analysis since CD-supported matrixes are known to effectively suppress matrix-related ion signals. In this study, we aimed to find the optimal CD-supported matrix for the analysis of the nonderivatized sex steroids. Our results showed that the ${\alpha}CD$-supported 2,5-dihydroxybenzoic acid (DHB) matrix efficiently ionized all three major classes of sex hormones, estrogens, androgens, and progestagens, with low or no matrix background and also with high sensitivity. In addition, the ${\alpha}CD$-supported DHB matrix mainly generated molecular ions or protonated ions of sex hormones, and this enabled us to obtain information-rich tandem mass spectra which potentially lead to unambiguous identification of steroid species from complex metabolite mixtures.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1621-1627
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• 2010

The investigation of the catalytic activity of supported rhodium(I) complex [Rh(P-S)$(CO)_2$] (P-S; polymer anchored salicylic acid) toward the reductive carbonylation of nitrobenzene in DMF medium has been reported. Use of basic cocatalysts in the reaction medium enhanced the percentage of more useful phenyl carbamates. Spectroscopic studies indicate that the reaction proceeds through a dimer species [Rh(HS)(CO)(C(O)$OCH_3$)(${\mu}-OCH_3)]_2$ and phenyl isocyanate is formed as an intermediate. A plausible reaction mechanism based on the identification of reactive intermediates from the soluble rhodium variety has been proposed for the carbonylation process.

• Membrane and Water Treatment
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• v.4 no.4
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• pp.277-291
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• 2013

The transport and recovery of Levafix brilliant red E-4BA and Levafix brilliant red E-6BA were investigated using polytetrafluoroethylene (PTFE) fiber based supported liquid membrane containing tetra butyl ammonium bromide (TBAB) in coconut oil as a carrier. The influencing parameters studied are: pH of the feed solution, concentration of dye in the feed solution, extractant concentration, and various kind of stripping agent, rate of stirring, time of transport, reusability of membrane and stability of membrane. Increase in TBAB concentration inside the membrane enhances the flux with its maximum value at $1.553{\times}10^{-4}$ M TBAB. Further increase in the concentration of TBAB leads to decreased rate of transport due to increase in viscosity of membrane liquid. The optimum conditions for dye transport are: pH of feed ($7{\pm}0.1$), $1.553{\times}10^{-4}$ M extractant concentration, 350 rpm for stirring, $4.9{\times}10^{-1}$ M potassium hydrogen phthalate as a stripping solution, the time of transport 6 h. It was noticed that flux values were increased with increasing dye concentration in the feed phase. Applying this study to textile wastewater, dyes were transported up to 98% in 6 h. This recovery technique is rewarding to environment and economic.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1671-1672
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• 2005

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2242-2246
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• 2010

New 3,7-diphenylthieno[3,2-e]bis[1,2,4]triazolo[4,3-a:4',3'-c]pyrimidine derivatives were easily synthesized at room temperature in good yield by the oxidative cyclization of thienopyrimidinyl hydrazones with alumina-supported calcium hypochlorite ($Ca(OCl)_2/Al_2O_3$).

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1320-1322
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• 2008

Phosphomolybdic acid supported on silica gel (PMA-$SiO_2$) is an efficient catalyst for the activation of TMSCN for the facile cyanosilylation of various aldehydes. Cyano transfer from TMSCN to aldehyde proceeds smoothly at rt in presence of 0.8 mol % of PMA-$SiO_2$ leading to a range of cyanosilylether in excellent yield (mostly over 93%) within short reaction time (30 min). The catalyst can be recovered and reused several times without loss of activity.