• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.203-213
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• 1996

In physical and reactive extraction system using equilibrium extraction equipment, the effects of extractants, concentration of extractant, and solvent on the degree of extraction were investigated. The organic acids used were acrylic acid and metacrylic acid. Extractants were n-octylamine(OA), di-n-octylamine(DOA), tri-n-octylamine(TOA) and tri-octylmetyl ammonium chloride(TOMAC ; Aliquat 336). We found that the degree of extraction for reactive extraction was 2~9 times than that for physical extraction and that effect of extractants on the degree of extraction of organic acid was the order of OA

• Journal of the Mineralogical Society of Korea
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• v.20 no.3
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• pp.155-163
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• 2007

A novel route to the synthesis of tetramethoxysilane and other silicon alkoxides is described using siliceous mudstone as the raw material. The reaction of amorphous silica with triethanol-amine is enhanced by using an alkali metal hydroxide catalyst to form a range of triethanol-amnine-substituted silatrane species. These can undergo alkoxide exchange in acidic alcohols to form alkoxysilatranes, tetraalkoxysilanes, hexaalkoxydisiloxanes and higher siloxanes. Products were identified by FT-IR spectroscopy, XRD, SEM, 1H and 13C NMR spectroscopy, or gas chromatography.

• YAKHAK HOEJI
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• v.55 no.3
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• pp.251-259
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• 2011

Cigarette smoke condensate (CSC) is known to be carcinogenic compound. CSC contains many organic compounds such as polycyclic aromatic hydrocarbons (PAHs), and heterocyclic amine compounds (HCAs). Reactive oxygen species (ROS) are also generated and induce oxidative DNA damage during the metabolism of CSC. The rat microsome mediated and DNA repair enzyme treated comet assays together with conventional comet assay were performed to evaluate the mechanisms of CSC genotoxicity. The organic extract of CSC induced oxidative and microsome mediated DNA damage. Vitamin C as a model antioxidant reduced DNA damage in endonuclease III treated comet assay. One of flavonoid, galangin as a CYP1A1 inhibitor, reduced DNA damage in the presence of S-9 mixture. The ethanol extracts of the mixed vegetables (BV) or the mixed fruits (BF) showed potent inhibitory effects against CSC induced DNA damage with oxidative DNA lesions and in the prescence of S-9 mixture. These results indicate that BV and BF could prevent CSC-induced cellular DNA damage by inhibiting oxidative stress and suppressing cytochrome P450 in mammalian cells.

• Macromolecular Research
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• v.12 no.3
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• pp.263-268
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• 2004

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4'-oxydianiline, and N,N -dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D$\_$sf/). The maximum value of D$\_$sf/ we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D$\_$sf/ of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D$\_$sf/ to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD 100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.416-421
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• 1995

The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0 $^{\circ}C)$ in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.

• Clean Technology
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• v.27 no.2
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• pp.115-123
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• 2021

This study demonstrates a new method for the synthesis of organic-inorganic hybrid particles composed of an inorganic silica shell and organic core particles. The organic core particles are prepared with a uniform size using droplet-based microfluidic technology. In the process of preparing the organic core particles, uniform droplets are generated by independently controlling the flow rates of the dispersed phase containing photocurable resins and the continuous phase. After the generation of droplets in a microfluidic device, the droplets are photo-polymerized as particles by ultraviolet irradiation at the ends of microfluidic channels. The core particle is coated with a nano complex composed of polyallylamine hydrochloride (PAH) and phosphate ion (Pi) through strong non-covalent interactions such as hydrogen bonding and electrostatic interaction under optimized pH conditions. The polyamine nano complex rapidly induces the condensation reaction of silicic acid through the arranged amine groups of the main chain of PAH. Therefore, this method enabled the preparation of organic-inorganic hybrid particles coated with inorganic silica nanoparticles on the organic core. Finally, we demonstrated the synthesis of organic-inorganic hybrid particles in a short time under ambient and environmentally friendly conditions, and this is applicable to the production of organic-inorganic hybrid particles having various sizes and shapes.

• Journal of the Korean Chemical Society
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• v.28 no.2
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• pp.130-134
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• 1984

The polarographic behavior of benzeneazoresorcinol (BAR) in acetonitrile as an aprotic solvent has been investigated by direct current polarography and controlled-potential coulometry. The reduction of BAR in $1.0{\times}10^{-2}$M tetraethylammonium perchrolate solution proceeds along four one-electron steps to give the corresponding amine compounds. Each reduction wave was considerably diffusion-controlled and not completely reversible.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.10-21
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• 1999

The purpose of study were to research the characteristics of water variation adding humic acids to distilled water after ozonation. Upon investigating pH variation with contact time after providing distilled water+air, distilled water+ozone and distilled water-humic acid-air in reactor, it reduced after 60 minute in inletting air and in spite of short contact time did suddenly in inletting ozone. TOC and UV-254 continued to increase with contact time of ozone and humic acids. $NH^{4+}-N$ did slowly increase or decrease after constant contact time of ozone, because $NH^{4+}-N$ was converted into $No^3-N$ by ozone. T-N did suddenly increase after 90minute, but T-P did rarely fluctuate for total experiment. Total 30 species of organic matter were detected by GS/MSD, but 14 species did really tend to increase except for matter identified in distilled water and blank test. Humic acids generated $aliphatic{\cdot}aromatic$ hydrocarbon, alcohol and amine etc., and did various matters without inflow course of contaminants.

• BMB Reports
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• v.36 no.3
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• pp.251-257
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• 2003

Agmatine, an amine and organic cation, reduced $H_2O_2$ that was generated by hyperglycemia, and transcription factors such as NF-${\kappa}B$ and AP-1 activity in the mesangial cells that were exposed to high glucose. However, spermine which shares a strong nucleophilic structure with agmatine decreased the $H_2O_2$ levels and AP-1, but not the NF-${\kappa}B$ activity. Possible roles for agmatine and spermine in decreasing fibronectin are discussed, and the signaling pathway for agmatine-reduced fibronectin accumulation is presented.

• Textile Coloration and Finishing
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• v.1 no.1
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• pp.26-34
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• 1989

The selective chemical degradation or etching of PET based on an organic amine attack on the ester group. The techniques involves the chemical removal of loss ordered amorphous regions or crystalline regions, which are essentially unaffected by the degradative etchant. Thus, most of previous studies have limited to consideration which has been given to structural changes taking place. Therefore, this study was carried out to investigate surface characterization, dyeing properties of PET film hydrazinolyzed with hydrazine hydrate in methanol. PET film was treated with 30% hydrazine hydrate in methanol at $30^\circ{C}$ for various time intervals. The total surface tension of treated PET increased, the dispersion force decreased and the hydrogen bonding force increased. The equilibrium dye adsorption, dyeing rate and apparent diffusion coefficient of acid dyes increased, and the apparent activation energies of diffusion decreased.