• Applied Biological Chemistry
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• v.49 no.4
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• pp.339-342
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• 2006

Canna generalis was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. from the EtOAc and n-BuOH fractions, four compounds were isolated through the repeated silica gel and ODS column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as $\beta$-sitosterol(1), linoleic acid methyl ester(2),1-O-oleoyl-2-O-linoleoyl-3-O-$\beta$-D-galactopyranosyl-sn-glycerol(3), and daucosterol(4). They were the first to be isolated from Canna generalis.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.110-116
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• 1991

As the model compounds, citral and n-octanol which possess similar characteristics and structures of low molecular weight insect pheromones and $({\pm})-5-hydroxy-4-methyl-heptan-3-one$ which shows the aggregation pheromones activity of the rice weevil and the maize weevil were microencapsulated with low molecular weight polyethylene(LMPE) and urea-formaldehyde resin as wall materials. The core materials were microencapsulated as small particles in LMPE and urea-formaldehyde resin polymers and the microencapsulated polymers were white powders. And the polymer made from urea-formaldehyde resin was better than that from LMPE as wall material. The slow releasing effect and the releasing patten of the microencapsulated core materials were examined by solvent extraction method and headspace sampling method. Citral and n-octanol and $({\pm})-5-hydroxy-4-methyl-heptan-3-one$ were release more than 40 days and 15 days, respectively. The releasing pattern of urea-formaldehyde resin microcapsules showed rather smooth decrease than that of LMPE and was maintained at steady level longer.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.274-279
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• 2006

To synthesize ZnO colloidal solution by a sol-gel process, zinc acetate ($C_{4}H_{6}O_{4}Zn{\cdot}2H_{2}O{\cdot}0.2\;mol$) and lithium hydroxide ($LiOH{\cdot}H_{2}O{\cdot}0.14\;mol$) in the ethanol were added to the solution containing a dispersing agent, hydroxypropyl cellulose (HPC). The nanosize and physical shape of the synthesized ZnO particles were determined by HPC acting as the dispersing agent. Nanosized ZnO particles were also obtained by a precipitation method based on zinc-2-ethylhexagonate. The precipitates were characterized by DLS, XRD, FE-SEM, and UV-vis. As the results, the ZnO colloids tend to self-assemble into a well-ordered hexagonal close-packed structure. The ZnO nanoparticles have an average diameter of nearly 40 nm with a narrow size distribution.

• Applied Chemistry for Engineering
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• v.18 no.1
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• pp.90-93
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• 2007

The effects of the host on the aggregation behavior of Oxaxine 720 (Ox720) were studied using absorption, fluorescence, and excitation spectra. The host materials used in this study were water, ethanol, and $TiO_2/P123$ nanocomposite. Ox720 aqueous solution contains a significant amount of H-aggregates, which increases with the increase in the concentration. In ethanol solution, Ox720 mainly exists in the monomer form and tiny amount of Ox720 exists in H- and J-aggregate forms. In the $TiO_2/P123$ nanocomposite thin film, the amount of H-aggregates was smaller than that in the aqueous solution but greater than that in the ethanol solution. $TiO_2$ nanocomposite thin film was proven to be a moderately good host for Ox720.

• Applied Chemistry for Engineering
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• v.7 no.4
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• pp.794-801
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• 1996

$TiO_2$ fine powders were synthesized via hydrolysis reaction of titanium isopropoxide in isopropanol solvent and the reaction rates were studied by use of UV spectroscopic method. The reactions were controlled to proceed to pseudo-first-order reaction in the presence of excess water in isopropanol solvent. The rate constants which varied with temperature and concentration of water were calculated by Guggenheim method. Reactions using $D_2O$ were also carried out to determine the catalytic character of water. n value of water molecules in transition state and the thermodynamic parameters showed that the reaction proceeded by $S_N2$ mechanism. $TiO_2$ powders synthesized in this reaction were almost spheric forms and had average particle size of $0.3{\mu}m$ diameter.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.352-356
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• 2014

PDMS modified epoxy resin with epoxy group (EMPDMS) was prepared from the reaction of ${\alpha},{\omega}$-aminopropylpolydimethylsiloxane and diglycidyl ether of bisphenol-A (DGEBA) based epoxy resin, and PDMS modified epoxy hybrid compound (EMPDMSH) was prepared by introducing alkylesteraminopropyl alkoxy silane to EMPDMS. Their structures were characterized using FT-IR, $^1H$-NMR and $^{29}Si$-NMR. Coating materials were prepared by mixing EMPDMSH base and solvent. Physical properties of the coating materials coated on epoxy/glass fiber composite film were measured according to the content of PDMS in EMPDMSH. Contact angle of coating film was increased 30 to 71 degree. Adhesive property of coating film was 5B degree better then epoxy or acrylate coating materials, and surface roughness was decreased as increasing in EMPDMSH.

• Clean Technology
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• v.20 no.1
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• pp.28-34
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• 2014

In this study, we synthesized $TiO_2$ supports with nanosized crystalline structure by solvothermal method and prepared $TiO_2$ supported Pd-Cu catalysts. It was shown that the crystalline size of $TiO_2$ support in the catalyst influenced on the catalytic activity of nitrate reduction in water. The catalyst with the smaller crystalline size of $TiO_2$ support presented faster nitrate reduction rate, but had low nitrogen selectivity due to high pH environment of reaction medium during the reaction. Through injection of carbon dioxide as a pH buffer, the nitrogen selectivity increased by about 60%. Furthermore, we investigated that the relationships between the catalytic performance and the physicochemical properties of the prepared catalysts characterized by $N_2$ adsoprtion-desorption, X-ray diffraction (XRD), $H_2$-temperature programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS).

• Journal of the Korean Ceramic Society
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• v.40 no.3
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• pp.279-285
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• 2003

Ferroelectric S $r_{0.9}$B $i_{2.1}$T $a_{1.8}$N $b_{0.2}$ thin films with 200 nm thicknesses were deposited on Pt/Ti $O_2$/ $SiO_2$/Si Substrates by a sol-gel method. In these experiments, Sr(O $C_2$ $H_{5}$)$_2$, Bi(TMHD)$_3$, Ta(O $C_2$ $H_{5}$)$_{5}$ and Nb(O $C_2$ $H_{5}$)$_{5}$ were used as precursors, which were dissolved in 2-methoxyethanol. After UV-irradiation and RTA processes, the remanent polarization value (2 $P_{r}$) of SBTN thin films with annealed at $650^{\circ}C$ was 8.49 and 11.94 $\mu$C/$\textrm{cm}^2$ at 3 V and 5 V, respectively.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.53-56
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• 2007

The aerial parts of Artemisia princeps PAMPANINI were extracted with 80% aqueous MeOH and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2$O, successively. From the EtOAc fraction, five compounds were isolated through the repeated silica gel and ODS column chromatog-raphies. They were determined as friedelin (1), ${\beta}$-amyrin (2), ${\beta}$-amyrin acetate (3), camphanediol (4) and hispidulin (5) on the basis of spectral data, respectively.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.60-64
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• 2008

The aerial parts of Spathiphyllum cannifolium were extracted with 80% aqueous MeOH and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, three compounds were isolated through the repeated silica gel, ODS, Sephadex LH-20 column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as stigmasterol (1), $(2S)1-O-linolenoyl-2-0-myristoyl-3-0-{\beta}-D-galactopyranosyl-sn-glycerol$ (2) and stigmasterol glucoside (3). They were the first to be isolated from Spathiphyllum cannifolium.