• Bulletin of the Korean Chemical Society
• /
• v.16 no.11
• /
• pp.1074-1079
• /
• 1995

Poly(dichlorophosphazene) having low molecular weight (M&bar;w∼104) was synthesized by the thermal reaction of hexachlorocyclotriphosphazene in the presence of excess AlCl3 (>2%) as catalyst. Using the poly(dichlorophosphazene), poly[bis(ethylglycino)phosphazene], poly[bis(glycinemethylamido)phosphazene], and poly[(glycinemethylamido)(methylamino)phosphazene] were prepared. Diammineplatinum(Ⅱ) complex cation was introduced into these derivatized phosphazene polymers, and the resultant polymers containing the platinum(Ⅱ) moiety were charaterized by means of elemental analysis, IR and NMR spectroscopies, and then subjected to in vitro and in vivo assays of antitumor activity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.281-281
• /
• 2008

최근 높은 비표면적, 우수한 결정성, 나노스케일의 크기 등 다양한 물리 화학적 특성을 지닌 1차원 나노구조체를 이용한 가스센서 연구가 활발히 진행되고 있다. 가스센서는 네트워크 된 나노선들 이용하여 벌크, 박막 보다 극대화된 비표면적으로 가스 감도와 반응 속도를 향상시킬 수 있었다. 촉매 첨가를 위해 Acetylacetone 용액 7 ml에 10 mM이 되도록 Pt 분말을 첨가하여 촉매용액을 제조하였다. 마이크로피펫을 이용하여 미량을 센서의 감응체 부문에 뿌려 대기 중에서 건조한 후 센서의 감도를 측정하였다. 측정은 $250^{\circ}C$에서 일산화탄소 가스 500 ppm의 가스농도로 촉정하였을 때 촉매가 첨가된 센서가 70% 이상의 개선된 감도를 나타내었다. 이는 나노선에 분산된 촉매에 주입되는 가스가 흡착되고 다시 표면의 산소와 반응하여 전기전도도를 변화시키는 것으로 보인다. 첨가된 촉매에 대한 영향을 분석하기 위해 AES, XRD, FT-IR, TEM 등의 분석을 실시하였다.

• Analytical Science and Technology
• /
• v.10 no.4
• /
• pp.264-273
• /
• 1997

Anodic oxidation reaction was applied to remove trihalomethanes in an aqueous solution. Each component was determined by using solid phase microextraction(SPME) fiber and GC-ECD. Anodic and cathodic compartments were separated in order to protect contaminants and connected by $KNO_3$-agar bridge. The calibration graphs of the 6 THM components were shown good linearlity from a few ppb up to a few hundreds ppb concentration level. Anodes such as platinum(Pt), titanium(Ti). zircornium(Zr), titanium metal coated with iridium(Ti-Ir), and glassy carbon coated with mixed valence ruthenium(mv Ru) were tried to remove the THMs at different potentials. The best result was obtained on the Ti-Ir anode applied 9 volts DC. The electrode could effectively remove almost all the THM components from the stirring solution within about 1.5 hours. The glassy carbon electrode coated with mixed valence ruthenium showed excellent removing effect at the begining, but the maximum removing level was remained at 60% probably due to the destruction of the electrode surface. The concentration of chloroform, however, tends to be increased due to the electrode reaction producing the component at the condition.

• Journal of the Korean Chemical Society
• /
• v.56 no.6
• /
• pp.679-691
• /
• 2012

New series of metal complexes of Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Pt(II) with 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) have been synthesized and characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, $^1H$ NMR, mass and ESR) and thermal studies. The IR data suggest different coordination modes for HCPTS which behaves as a monobasic bidentate with all metal ions except Cu(II) and Zn(II) which acts as a monobasic tridentate. Based on the electronic and magnetic studies, Co(II), Cu(II), Pd(II) and Pt(II) complexes have square - planner, Ni(II) has mixed stereochemistry (tetrahedral + square planar), while Zn(II) is tetrahedral. Molar conductance in DMF solution indicates the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complex show $g_{\parallel}$ (2.2221) > $g_{\perp}$ (2.0899) > 2.0023 indicating square-planar structure and the presence of the unpaired electron in the $d_x2_{-y}2$ orbital with significant covalent bond character. The thermal stability and degradation kinetics of the ligand and its metal complexes were studied by TGA and DTA and the kinetic parameters were calculated using Coats-Redfern and Horowitz-Metzger methods. The complexes have more antibacterial activity against some bacteria than the free ligand. However, the ligand has high anticancer activities against HCT116 (human colon carcinoma cell line) and HEPG2 (human liver hepatocellular carcinoma cell line) compared with its complexes.

• Journal of the Korean Chemical Society
• /
• v.42 no.2
• /
• pp.177-183
• /
• 1998

By the reactions of a $C_{2}$-chiral ligand, (+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene(6) with $[\pi-allyl chloroplatinum(II)]_4$, and $CpCo(CO)_2$ respectively, three new complexes, ($\pi$-allyl)platinum(II)(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene perchlorate(1), ($\pi$-allyl)platinum(II)(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene chloride(2), ($\eta^5$-cyclopentadienyl)cobalt(I)-(+)-11S,12S-bis[2,2'-(diphenylphosphino)benzanilido]-9,10-dihydro-9,10-ethanoanthracene(3) were prepared. $\eta^3$-Cyclohexenyl)palladium(II)1,2-bis(diphenylphosphino)ethane perchlorate(4) was obtained by the reaction of ($\eta^3$-cyclohexenyl)palladium(II) chloride dimer with a symmetric ligand, 1,2-bis(diphenylphosphino)ethane and lithium perchlorate. These complexes were identified by NMR-, IR-, and Mass-Spectrophotometers and elemental analyzer.

• Korean Chemical Engineering Research
• /
• v.52 no.6
• /
• pp.695-700
• /
• 2014

Proton Exchange Membrane Fuel Cells (PEMFC) can generate hydrogen and oxygen from water by electrolysis. But the electrode and polymer electrolyte membrane degrade rapidly during PEM water electrolysis because of high operation voltage over 1.7V. In order to reduce the rate of anode electrode degradation, unsupported $IrO_2$ catalyst was used generally. In this study, Pt/C catalyst for PEMFC was used as a water electrolysis catalyst, and then the degradation of catalyst and membrane were analysed. After water electrolysis reaction in the voltage range from 1.8V to 2.0V, I-V curves, impedance spectra, cyclic voltammograms and linear sweep voltammetry (LSV) were measured at PEMFC operation condition. The degradation rate of electrode and membrane increased as the voltage of water electrolysis increased. The hydrogen yield was 88 % during water electrolysis for 1 min at 2.0V, the performance at 0.6V decreased to 49% due to degradation of membrane and electrode assembly.

• Journal of Sensor Science and Technology
• /
• v.9 no.2
• /
• pp.90-95
• /
• 2000

The substrate for pyroelectric IR sensor which has orientation similar to MgO single crystal was fabricated by depositing the MgO thin film on $Si_3N_4/SiO_2/Si_3N_4$/Si. The MgO thin film was deposited by RF magnetron sputtering. The c-axis orientation of PLT thin film deposited on Pt/MgO(100)/$Si_3N_4/SiO_2/Si_3N_4$/Si substrate was investigated. The MgO thin film deposited at $500^{\circ}C$ at a gas pressure of 30 mTorr with RF power of 160 W exhibited a good a-axis orientation. The PLT thin films deposited on these substrates also exhibited c-axis orientation similar to the PLT thin films deposited on MgO single crystal substrate.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.4
• /
• pp.369-375
• /
• 2010

The study on the characteristics of nitrous oxide catalytic decomposition was carried out to utilize the nitrous oxide as a propellant. The Pt, Ir and Ru were synthesized to select a high performance catalyst for the nitrous oxide decomposition reaction. The respective catalyst precursors were loaded in the $Al_2O_3$ support using an wet impregnation method. The $N_2O$ conversion as a variation of space velocity and reaction temperature was measured using a tubular reactor. The catalyst loss was measured to evaluate the durability of catalysts after the reaction at $800^{\circ}C$ for 2 hours. The $N_2O$ conversion was increased at the decrease of space velocity and at the increase of temperature. The Ru/$Al_2O_3$ catalyst had the highest $N_2O$ conversion at low temperature and the best durability.

• Korean Chemical Engineering Research
• /
• v.54 no.6
• /
• pp.734-745
• /
• 2016

This review article described the electrochemical Frumkin, Langmuir, and Temkin adsorption isotherms of over-potentially deposited hydrogen (OPD H) and deuterium (OPD D) for the cathodic $H_2$ and $D_2$ evolution reactions (HER, DER) at Pt, Ir, Pt-Ir alloy, Pd, Au, and Re/normal ($H_2O$) and heavy water ($D_2O$) solution interfaces. The Frumkin, Langmuir, and Temkin adsorption isotherms of intermediates (OPD H, OPD D, etc.) for sequential reactions (HER, DER, etc.) at electrode/solution interfaces are determined using the phase-shift method and correlation constants, which have been suggested and developed by Chun et al. The basic procedure of the phase-shift method, the Frumkin, Langmuir, and Temkin adsorption isotherms of OPD H and OPD D and related electrode kinetic and thermodynamic parameters, i.e., the fractional surface coverage ($0{\leq}{\theta}{\leq}1$) vs. potential (E) behavior (${\theta}$ vs. E), equilibrium constant (K), interaction parameter (g), standard Gibbs energy (${\Delta}G_{\theta}{^{\circ}}$) of adsorption, and rate (r) of change of ${\Delta}G_{\theta}{^{\circ}}$ with ${\theta}$ ($0{\leq}{\theta}{\leq}1$), at the interfaces are briefly interpreted and summarized. The phase-shift method and correlation constants are useful and effective techniques to determine the Frumkin, Langmuir, and Temkin adsorption isotherms and related electrode kinetic and thermodynamic parameters (${\theta}$ vs. E, K, g, ${\Delta}G_{\theta}{^{\circ}}$, r) at electrode/solution interfaces.

• Korean Chemical Engineering Research
• /
• v.54 no.4
• /
• pp.555-559
• /
• 2016

In this study, new platinum complexes were synthesized utilizing the ligand of a 2,2'-bispyrimidine (bpim), 2,2'-bipyridine (bpy), 5,5'-dimethyl-2,2'-bipyridine (5,5-mebpy), 5'-bromo-2,2'-bipyridine (5-brbpy), 5,5'-dibromo-2,2'-bipyridine (5,5-brbpy), 4,4'-dimethyl-2,2'-bipyridine (4,4-mebpy), 4,4'-dihexyl-2,2'-Bipyridine (4,4-hebpy), 1,10'-Phenanthroline (phen), 3,4,7,8'-tetramethyl-1,10'-Phenanthroline (3,4,7,8-phen). In order to determine chemical structure of Synthesized platinum complexes, $^1H(^{13}C)$-NMR, UV-vis and FT-IR were used and optical physics and chemical properties were measured PL. In the case of platinum complexes, wavelength has been identified 356~421 nm. Quantum efficiency in DMSO solution was appeared 0.05~0.46.