• Bulletin of the Korean Chemical Society
• /
• 제31권11호
• /
• pp.3272-3278
• /
• 2010

Synthesis and structural characterization of peripherally ferrocene-substituted zinc phthalocyanine (ZnPc-Fc) were carried out for efficient far-red/near-IR performance in dye-sensitized nanostructured $TiO_2$ solar cells. Incorporating ferrocene into phthalocyanine strongly improved the dye solubility in polar organic solvents, and reduced surface aggregation due to the steric effect of bulky ferrocene substituents. The involvement of electron transfer reaction pathways between ferrocene and phthalocyanine in ZnPc-Fc was evidenced by completely quenched fluorescence from S1 state (< 0.08% vs ZnPc). Strong absorption bands at 542 and 682 nm were observed in the transient absorption spectroscopy of ZnPc-Fc in DMSO, which was excited at a 670 nm laser pulse with a 15 ps full width at half maximum. Also, the excited state absorption signals at 450 - 600 and 750 - 850 nm appeared from the formation of charge separated state of phthalocyanine's anion. The lifetime of the charge separate state in ZnPc-Fc was determined to be $170{\pm}8$ ps, which was almost 17 times shorter than that of the ZnPc.

• 대한화학회지
• /
• 제37권8호
• /
• pp.717-722
• /
• 1993

물에서 [PtCl$_4$]^{2-}$의 백금(II)에 결합된 클로로리간드를 디티오카바메이트로 치환시켜 [Pt(A)], [Pt(B)$_2$]Cl$_2$, [Pt(C)$_2$] 및 [Pt(D)(CH$_2$=CH$_2$)Cl]Cl를 합성하였다. 백금 착물은 원소분석, 적외선 및 자외선-가시광선 스펙트럼과 전도도 측정을 하여 이들의 성질을 조사하였따. 이들 백금(II)의 디티오카바메이트류 착물은 물, 알코올, 디메틸술폭시드 및 티메틸포름아미드와 같은 극성용매에 잘 녹았다. 이들 백금(II) 착물의 원소분석과 물리적 측정결과에서부터 그 가능한 구조를 제시하였다.

• Korean Membrane Journal
• /
• 제4권1호
• /
• pp.25-35
• /
• 2002

The gas permeation properties have been studied on carbon molecular sieve (CMS) membranes prepared by pyrolysis of P84 polyimide under various conditions. P84 polyimide shows high permselectivities (O$_2$/N$_2$= 9.17 and CO$_2$/N$_2$= 35) for various gas pairs and has a good processibility because it is easily soluble in high polar solvents such as N-methylpyrrolidinone (NMP), dimethylformamide (DMF), and N,N-dimethylacetamide (DMAc). After pyrolysis under Ar flow, the change in the heating rate was found to affect the gas permeation properties to some extent. The permeabilities of the selected gases were shown to be in the order He ＞ CO$_2$＞ O$_2$＞ N$_2$for all the CMS membranes, whose order was in accordance with the order of kinetic gas diameters. It also revealed that the pyrolysis temperature considerably influenced the gas permeation properties of the CMS membranes derived from P84 polyimide. The CMS membranes pyrolized at 700$\^{C}$ temperature exhibited the highest permeability with relatively targe loss in permselectivity. This means that the pyrolysis temperature should be varied in accordance with target gases to be separated.

• 한국분말재료학회지
• /
• 제25권4호
• /
• pp.291-295
• /
• 2018

A conductive additive is prepared by dispersing multi-walled carbon nanotubes (MWCNTs) on Cu powder by mechanical milling and is distributed in epoxy to enhance its electrical conductivity. During milling, the MWCNTs are dispersed and partially embedded on the surface of the Cu powder to provide electrically conductive pathways within the epoxy-based composite. The degree of dispersion of the MWCNTs is controlled by varying the milling medium and the milling time. The MWCNTs are found to be more homogeneously dispersed when solvents (particularly, non-polar solvent, i.e., NMP) are used. MWCNTs gradually disperse on the surface of Cu powder because of the plastic deformation of the ductile Cu powder. However, long-time milling is found to destroy the molecular structure of MWCNTs, instead of effectively dispersing the MWCNTs more uniformly. Thus, the epoxy composite film fabricated in this study exhibits a higher electrical conductivity than 1.1 S/cm.

• 한국수산과학회지
• /
• 제18권1호
• /
• pp.23-28
• /
• 1985

The extraction rate of lipids from the chopped whole fish was studied with various solvents. Factors which can influence on the extraction rate such as temperature, moisture content, agitation speed and solvent were also examined. In the early stage of extraction, it is considered that the rapid extraction was attributed to cell destruction which occurs in chopping the whole fish and in the later stage, the extraction rate was increased linearly with extraction time. The effect of agitation on the extraction rate had a great influence on the early stage of extraction. In agitation speed of 100, 200, 300 and 500 r.p.m. the slopes of extraction curve were -0.075, -0.075, -0.069 and -0.064, respectively. Extractability between hydrophilic and hydrophobic solvent showed a great difference. It is suggested that extractability difference between acetone and isopropyl alcohol is due to acetone property which can not extract phospholipids in polar lipids. Extractability of lipids was increased with increasing temperature and decreased with increasing moisture content.

• Journal of Ginseng Research
• /
• 제1권1호
• /
• pp.25-28
• /
• 1976

몇 가지 유기용매를 사용하여 인삼 추출액을 분별 분리하여 몇 개의 분칠들을 얻어서 이들이 RNA중합효소의 활동성에 미치는 영향을 조사하였다. 백삼과 홍삼에서 모두 RNA 중합효소의 활동성에 양성적인 효과를 가진 분획들을 얻었다. 백삼의 경우 RNA 중합효소에 양성적인 효과를 미치는 성분들은 전체 메탄을 추출액 분획, 초산에틸 추 출모액 및 이 모액의 수용성 분획들에서 확인되었고 흥삼의 경우에는 전체 메탄을 추출액 분획과 에테르 분획들에서 확인되었다. 이 사실은 중합효소에 양성적인 효과를 나타내는 성분들이 무극성 및 극성 부분들로 이루어져 있으며, 그들이 홍삼의 가공과 정에서 두 부분으로 분해되었을 것이라는 것을 암시의 준다.

• 대한화학회지
• /
• 제57권6호
• /
• pp.726-730
• /
• 2013

Complexes synthesized by reacting alkyl and aryl phosphines with different transition metals are of great interest due to their catalytic properties. Many of the phosphine complexes are soluble in polar solvents as a result they find applications in homogeneous catalysis. In our present work we report, four transition metal complexes of Ni(II), Pd(II), Pt(II) and Ru(II) with an asymmetrical ditertiaryphosphine ligand. The synthesized ligand bears a less electronegative substituent such as methyl group on the aromatic nucleus hence makes it a strong ${\sigma}$-donor to form stable complexes and thus could effectively used in catalytic reactions. The complexes have been completely characterized by elemental analyses, FTIR, $^1HNMR$, $^{31}PNMR$ and FAB Mass Spectrometry methods. Based on the spectroscopic evidences it has been confirmed that Ni(II), Pd(II) and Pt(II) complexes with the ditertiaryphosphine ligand showed cis whereas the Ru(II) complex showed trans geometry in their molecular structure.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.394-394
• /
• 2007

Transparent conductive films can serve as a critical component in displays, solar cells, lasers, optical communication devices, and solid state lighting. Carbon nanotube (CNT) based transparent conductive films are fabricated on glass and polymer substrates. CNTs typically exist in form of quasi-crystalline bundles or highly entangled bundles containing tens of individual nanotubes. To achieve full potential, CNTs must be dispersed in a solvent or other organic media. CNTs are acid treated with nitric acid then the stable dispersion of CNTs in polar solvent such as alcohols, DMF, etc. is achieved by sonication. The solubility of CNTs correlates well with the area ratio of the D and G bands from Raman spectrum. Thin films are formed from well dispersed CNT solutions using spray coating method. CNT thin films exhibit a sheet resistance ($R_s$) of nearby $10^3\;{\Omega}/sq$ with a transmittance of around 80% on the visible light range, which is attributed by excellent dispersion and interaction among CNTs, solvents and polymeric binders.

• Macromolecular Research
• /
• 제9권6호
• /
• pp.327-331
• /
• 2001

A new soluble photosensitive poly(amide-co-imide) containing p-phenylenediacryloyl moiety was synthesized and its photoreactivity was characterized. The copolymer was synthesized fromp-phenylenediacryloyl chloride, 4,4-(hexafluoroisopropylidene)diphthalic anhydride and two equivalents of bis(4-aminophenyl) ether in NMP with a subsequent chemical imidization of the resulting poly[amide$\xi$ο-(amic acid)] by acetic anhydride and pyridine. The structure and thermal properties of the polymer were characterized by spectroscopic methods and thermal analyses. The polymer was stable up to 350$\^{C}$, showed good solubility in polar aprotic solvents, and became insoluble after UV irradiation due to the[2+2] cycloaddition of phenylenediacryloyl moiety. Photoreactivity of the polymer was investigated in solution or as a film with respect to the various exposure conditions by UV/Vis spectroscopy. The photosensitivity was noticeably increased with the irradiation temperature, especially in the presense of photosensitizer. The reason for the increased sensitivity was speculated based on the flexibilization of main chain at elevated temperature. Exposure characteristic curves were obtained from the gel fraction experiments after UV irradiation. The sensitivity and contrast at 160$\^{C}$ were measured to be 293 mJ/㎠ and 1.64, respectively.

• Korean Membrane Journal
• /
• 제3권1호
• /
• pp.9-16
• /
• 2001

The diamide-diamine having carboxylic acid was prepared by direct condensation of 1,2,4-benzenetricarboxylic acid with bits[4- (3-aminophenoxy ) phenyl] sulfone and bits(4-aminouhenyl)-1,4- diisopropylbenzene in medium consisting of triphenylphosphite, LiCl, and N-methyl-2-pyrrolidone. Copoly (amide-imide) derivatives with high molecular weight could be synthesized by one-step polycondensation of prepared diamide-diamine having carboxylic acid and various dianhydride compounds. Depending on the chemical structure and composition of polymer backbones, the viscosities of polymers were found to range between 0.87∼ 1.57 dL/B. All the polymers showed good thermal stability up to 320$\^{C}$ and the 10% weight loss temperature was observed in the range of 450∼540$\^{C}$ in a thermogravimetric traces. The glass transition was recorded in the temperature range of 200 ∼ 270$\^{C}$. All the polymers showed an amorphous nature on a differential scanning calorimetric thermograms. These polymers generally had good mechanical properties and readily soluble in various polar solvents. Further, it was proved that their properties could be determined from the composition.