• 대한화학회지
• /
• 제40권11호
• /
• pp.686-691
• /
• 1996

Viologen 유도체를 합성하여 이들의 electrochromic(전기변색) 특성을 조사했다. 1, 1'-diethyl-4, 4'-bipiridinium dibromide(EV), 1, 1'-dipropyl-4, 4'-bipyridinium dibromide(PV), 1, 1'-dibuthyl-4, 4'-pyridinium dibromide(BV), 1-ethyl-1'-butyl-4, 4'-bipyridinium dibromide(EBV)를 대상으로 하여 propylene carbonate/methanol 용액내에서 전기변색성을 검토하였다. 또한 전장하에서 EV와 EBV의 cation radical은 dimer를 형성하는 것을 알 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제35권9호
• /
• pp.2758-2764
• /
• 2014

We demonstrated the synthesis of organic carbonates using alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates and alcohol in the presence of aluminum chloride. Alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates were reacted with alcohol in the presence of $AlCl_3$ in toluene at room temperature to afford the corresponding unsymmetric and symmetric organic carbonates in good to excellent yields. These are efficient and convenient processes. Alkyl/aryl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylates are solid, stable and non-toxic $CO_2/CO_2R$(Ar) source. It is noteworthy that the reaction is carry out under an ambient and acidic conditions, the easy-to prepare and readily available starting materials and the quantitative isolation of reusable 4,5-dichloropyridazin-3(2H)-one.

• 한국수소및신에너지학회논문집
• /
• 제21권4호
• /
• pp.307-312
• /
• 2010

Poly (ether sulfone)s with Bisphenol-TP and Bisphenol-AF were prepared with Bisphenol-TP <4,4-dihydroxy tetraphenyl methane>, 4-Fluorophenyl sulfone, and Bisphenol-AF <4,4-(hexafluoroisopropylidene) diphenol> using Potassium carbonate in Sulfolane at $210^{\circ}C$. Sulfonated PBTP-AF were obtained by reaction of Chlorosulfuric acid with copolymers. A series of copolymers were studied by $^1H$-NMR spectroscopy, Differential Scanning Calorimeter (DSC), and Thermo Gravimetric Analysis (TGA). Sorption experiments were conducted to observe the interaction of polymers with water and methanol.

• 한국재료학회지
• /
• 제28권4호
• /
• pp.227-234
• /
• 2018

We investigate the effect of the modification of cellulose acetate propionate as an organic vehicle for silver paste on solar cell efficiency. For the modification of cellulose acetate propionate, poly(ethylene glycol) is introduced to the hydroxyl groups of a cellulose acetate propionate backbone via esterification reaction. The chemical structure and composition of poly(ethylene glycol) functionalized cellulose acetate propionate is characterized by Attenuated total reflectance Fourier transform infrared, $^1H$ nuclear magnetic resonance, differential scanning calorimetry and thermogravimetric analysis. Due to the effect of structural change for poly(ethylene glycol) functionalized cellulose acetate propionate on the viscosity of silver paste, the solar cell efficiency increases from 18.524 % to 18.652 %. In addition, when ethylene carbonate, which has a structure similar to poly(ethylene glycol), is introduced to cellulose acetate propionate via ring opening polymerization, we find that the efficiency of the solar cell increases from 18.524 % to 18.622 %.

• 한국세라믹학회지
• /
• 제35권3호
• /
• pp.209-218
• /
• 1998

세라믹스계 생체재료중에서 그 화학조성과 결정구조가 사람의 뼈와 매우 유사하여, 다른 재료보다 생체진화성이 월등히 우수한 수산화 아파타이트 분말을 용액침전법으로 제조하였다. 이때 용액침전법의 가장 큰 단점인 칼슘결손의 발생을 억제하고, 아울러 질소대신 공기중에서도 화학양론조성의 수산화 아파타이트 원료분말을 쉽게 합성할 수 있는 방법을 개발하였다. 즉, 공기중에 존재하는 CO2 기체로부터 형성된 반응용액중에 {{{{ {CO }`_{3 } ^{2- } }} 이온의 농도를 pH를 이용 조절함으로써 침전반응 및 여과공정을 공기중에서 수행하면서도 Ca의 결손이 없고 소결성이 매우 우수한 수산화 아파타이트 분말을 제조할 수 있었다.

• 한국가스학회지
• /
• 제5권4호
• /
• pp.27-32
• /
• 2001

온실효과의 주요 원인 물질인 이산화탄소를 고온$\cdot$고압에서 제거하기 위한 CaO 흡착제를 제조하였다. 흡착제는 석회석을 고압성형과 소성을 이용하여 제조하여 그 물성을 조사하고 회분식 흡착용기에서 흡착실험을 수행하였다. 세공면적은 성형압력으로 결정되며 세공분포는 이분산 형태를 갖는다. CaO의 $CO_2$ 흡착은 화학흡착이며 최대전환율은 $700^{\circ}C$에서 $80\%$에 근접한다.

• 한국응용과학기술학회지
• /
• 제24권2호
• /
• pp.109-116
• /
• 2007

2-Chlorobenzoyl hydrazine refluxed with benzoyl isothiocyanate and phenyl isothiocyanate in ethanol for 3 hours to give benzamide derivative (1) and anilinederivative (2) on yield of 71%and 95%, respectively. Benzamide derivative (1) reacted with ethanolic sodium hydroxide on reflux to afford cyclization product (3), followed by general substitution reaction of two steps to give acetamide (5), and derivatived acetamides 7a-7k, while aniline derivative (2) reacted with ethanolic sodium hydroxide on reflux to afford another cyclization product (4). Thiol (4) reacted with N-phenyl chloroacetamide in the presence of potassim carbonate to give acetamide derivative (6). Compounds 1-7kwere evaluated for their growth inhibition against five cancer cell lines, including human lung carcinoma (A-549), human prostate cancer (DU145), human colon adenocarcinoma (HT-29), human malignant melanoma (SK-MEL-2) and human ovary malignant ascites (SK-OV-3) with sulforhodamine B (SRB) assay. All compounds (1-7k) showed low inhibition activities under 50% on 100M concentration.

• Bulletin of the Korean Chemical Society
• /
• 제31권8호
• /
• pp.2219-2222
• /
• 2010

A density functional theory (DFT) study of $CO_2$ adsorption on barium oxide (BaO) adsorbents is conducted to understand the chemical activity of the oxygen site on the BaO (100) surface. This study evaluated the adsorption energies and geometries of a single $CO_2$ molecule and a pair of $CO_2$ molecules on the BaO (100) surface. A quantum calculation was performed to obtain information on the molecular structures and molecular reaction mechanisms; the results of the calculation indicated that $CO_2$ was adsorbed on BaO to form a stable surface carbonate with strong chemisorption. To study the interactive $CO_2$ adsorption on the BaO (100) surface, a pair of $CO_2$ molecules was bound to neighboring and distant oxygen sites. The interactive $CO_2$ adsorption on the BaO surface was found to slightly weaken the adsorption energy, owing to the interaction between $CO_2$ molecules.

• Archives of Pharmacal Research
• /
• 제15권1호
• /
• pp.87-90
• /
• 1992

The syntheses of novel heterocyclic base modified pyrimidine nucleosides are described. 5, 6-dimethyl-4-hydroxy-3-methoxy-1-$(\beta$-D-ribofuranosyl)2(1H)-pyridinone 7 was synthesized by condensation of silylated 5, 6-dimethyl4-hydroxy-3-methoxy-2(1H)-pyridione 7 was synthesized by condensation of silylated 5, 6-dimethyl-4-hydroxy-3-methoxy-2(1H)-pyridinone with $\beta$-D-ribofuranose-1-acetate-2, 3, 5-tribenzoate in dichloroethane in the presence of Lewis acid followed by debenzoylation. The 2, 2'-anhydro-5, 6-dimethyl-2-hydroxy-3-methoxy-1-$\beta$-D-arabinofuranosyl-4-pyridinone 8 was obtained from the reaction of the free ribonucleoside 7 and diphenyl carbonate in DMF. None of these compounds showed any significant antiviral ad antitumor activities in vitro tests.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
• /
• pp.334-337
• /
• 2004

Groundwater chemistry in Namwon area, Korea, was investigated to understand the contribution of geochemical processes on groundwater chemistry. For this study, a total of 279 groundwater samples were collected from 93 wells distributed over the study area. Higher concentrations of major ions are generally encountered in the shallow alluvial wells, suggesting that these chemicals are originated from the surface contamination sources. Mass balance analysis based on reaction stoichiometry reveals that the water chemistry is regulated by three major chemical processes: weathering of silicate/ carbonate minerals, input of C1/SO$_4$ salts, and nitrate generating processes. The results show that mineral weathering is the most dominating factor regulating the groundwater chemistry. However, the groundwaters with the higher salt concentration indicate the larger mineral weathering effect, suggesting that some part of the mineral weathering effect is also associated with the anthropogenic activities such as limes applied to the cultivated lands, carbonates (CaCO$_3$) in the cement materials.