• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3118-3122
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• 2010

The water soluble redox polymer, poly(N-vinylimidazole) complexed with Os(4,4'-dichloro-2,2'-bipyridine)$_2Cl]^+$ (PVI-[Os(dCl-bpy)$_2Cl]^+$), was electrodeposited on the surface of a glassy carbon electrode by applying cycles of alternating square wave potentials between 0.2 V (2 s) and 0.7 V (2 s) to the electrode in a solution containing the redox polymer. The coordinating anionic ligand, $Cl^-$ of the osmium complex, became labile in the reduced state of the complex and was substituted by the imidazole of the PVI chain. The ligand substitution reactions resulted in crosslinking between the PVI chains, which made the redox polymer water insoluble and caused it to be deposited on the electrode surface. The deposited film was still electrically conducting and the continuous electrodeposition of the redox polymer was possible. When cycles of square wave potentials were applied to the electrode in a solution of bilirubin oxidase and the redox polymer, the enzyme was co-electrodeposited with the redox polymer, because the enzymes could be bound to the metal complexes through the ligand exchange reactions. The electrode with the film of the PVI-[Os(dCl-bpy)$_2Cl]^+$ redox polymer and the co-electrodeposited bilirubin oxidase was employed for the reduction of $O_2$ and a large increase of the currents was observed due to the electrocatalytic $O_2$ reduction with a half wave potential at 0.42 V vs. Ag/AgCl.

• Advances in nano research
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• 제10권4호
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• pp.373-383
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• 2021

In this work, silver nitrate complexes of sulfanilamide-5-methyl-2-thiophene carboxaldehyde (SMTCA) ligand intercalated Zn/Al-layered double hydroxide [Ag-SMTCA-LDH] were synthesized for the potential application as an antimicrobial system. The SMTCA ligand was synthesized by reacting sulfanilamide and 5-methyl-2-thiophene carboxaldehyde in methanol and further complexation with silver nitrate metal ions [Ag-SMTCA]. The structural analyses of synthesized compounds confirmed an intercalation of Ag-SMTCA into Zn/Al-NO₃-LDH by flake/restacking method. SMTCA, Ag-SMTCA and Ag-SMTCA-LDH were characterized by ¹H nuclear magnetic resonance (¹H NMR) spectroscopy, Fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis) spectrophotometer, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). It was found that Ag-SMTCA-LDH exhibited good antimicrobial activity against both gram-positive (Bacillus subtilis, [B. subtilis], Staphylococcus aures, [S. aureus]) and gram-negative (Escherichia coli, [E. coli], Pseudomonas aeruginosa [P. aeroginosa]) bacteria as well as excellent antioxidant activity.

• 폴리머
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• 제25권5호
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• pp.719-727
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• 2001

유기광도전체에 있어서의 액정은 종래의 분자 배향성을 가지지 않는 비정성 고체계와는 달리 분자 배향성을 가지기 때문에 분자 사이의 질서도가 높아지게 되고, charge-carrier의 hopping을 방해하는 hopping site의 공간적인 틈이 작아져 고 이동도의 특성을 가질수 있다. 본 연구에서는 유기광도전체의 전하 수송층에 액정5CT를 혼합하여, charge-carrier수송특성에 있어서의 액정5CT의 영향을 관찰하였다. 액정5CT를 함유한 유기광도전체는 액정의 혼합비가 증가함에 따가 초기전위는 증가하였으며, 암감쇄는 감소하는 경향을 나타내었다. 감도는 5CT를 TNF와 OXD 각자에 대하여 40 wt%로 혼합한 시료의 경우에 가장 우수하게 나타났다. 형광거동을 관찰한 결과, 이는 전하수송재료와 액정5CT의 전하 수송착체에 의한 것으로, 액정5CT를 TNF와 OXD 각각에 대하여 40 wt%로 혼합한 시료의 경우가 다른 시료에 비해 전하 수송착체가 가장 잘 형성되어, 성공을 잘 수송하기 때문으로 나타났다.

• Macromolecular Research
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• 제16권2호
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• pp.134-138
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• 2008

A novel acrylol borate was designed and synthesized by reacting acrylate monomer and boric acid. The obtained acrylol borate was used as both gelator and anion receptor for the liquid electrolyte in a lithium secondary battery. It was found that the ionic conductivity of the gel polymer electrolyte (GPE) was as high as that of the liquid electrolyte, and the thermal stability of GPE was increased when only 2 wt% acrylol borate was incorporated into the liquid electrolyte. These results suggest that acrylol borate can be used as an effective additive to enhance the thermal stability of the electrolyte without adversely affecting its conductivity. It is believed that the strong complex formation between boron in the gelator and the anion of the salt is responsible for the enhanced thermal stability of the electrolyte solution and the increased ionic conductivity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.205-211
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• 2005

Water-soluble polyethyleneimine (PE) derivatives containing nucleic acid bases and hydrophilic amino acids such as homoserine (Hse) and serine were prepared by the activated ester method as nucleic acid models. From spectroscopic measurements, the polymers were found to interact with DNA accompanied by an induction of conformational change. Hypochromicity in UV spectra indicated that a stable polymer complex was formed between poly (A) with PEI­Hse-Ura by complementary hydrogen bonding with equimolar nucleic base units (adenine:uracil=1:1). The induced conformation of DNA by the interaction with the polymer containing uracil and homoserine (PEI-Hse-Ura) was concluded to be a super triple helical structure. The formation of the polymer complex, DNA: PEI-Hse-Ura, was found to be affected by the presence of metal ions such as $Ca^{2+}\;and\;Cu^{2+}$.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.73-78
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• 1988

The polymer electrolyte complex hydrogels consisting of poly (methacrylic acid) and poly (4-vinylpyrridine) were formed and 5-flurouracil and pilocarpine drugs were loaded on their hydrogels. Cumulative 5-FU released from PEC hydrogel was affected by the degree of loading and release rate of 5-FU was followed by the monolithic type. Cumulative pilocarpine released from PEC hydrogel increased by ionic interaction between cationic pilocarpine and anionic PMA. Release rate showed the zero order after burst effect.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1711-1713
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• 2000

We fabricated an IMI-O polymer containing an imidazole group that could form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the surface analysis and the electrical properties of metal ion complex of Langmuir-Blodgett (LB) films were investigated by using $\pi$-A isotherms. Atomoic force microscopy (AFM), current-voltage (I-V) measurements. In the $\pi$-A isotherms the molecular area was expanded with $Fe^{3+}$ concentration increase. It is considered that the expansion of molecular area is due to electrostatic repulsion between the polymer chains and hydrophobic increase of ionic strength. In the I-V characteristics, it is found that the limiting area has effects on the change of conductivity. And, the dielectric relaxation time decreased for increase of the $Fe^{3+}$ concentration.

• 폴리머
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• 제24권2호
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• pp.268-275
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• 2000

고전기장을 이용하여 제조한 도전성 탄소섬유/폴리에틸렌 복합필름에 있어서 고분자 점착하층의 두께가 제조된 필름의 체적비저항과 인장강도에 미치는 효과에 대하여 연구하였다. 탄소섬유(CF) 함량과 CF 층밀도에 따라 제조된 필름의 체적비저항과 인장강도의 점착하층에 대한 의존성의 양상은 복잡하게 나타났다. 이는 점착하층의 증가에 따라서 필름 하층면에 중심부나 위쪽에 비하여 CF 농도가 낮은 절연성 고분자층의 두에가 증가하고 필름 상층면 근처에서는 CF의 함침에 필요한 고분자 매트릭스의 양이 적어져 매트릭스 함침이 불충분하여 기공이 포함된 구조를 형성시키는 효과와 증가된 매트릭스의 유동성을 바탕으로 CF 분산성이 향상되고 동시에 보다 치밀한 구조가 형성되는 두 가지 상반되는 효과의 상대적 기여 정도의 차이를 통하여 설명할 수 있었다. 이들 결과는 전자파 차폐용 고도전성 고분자 차폐필름의 제조에 있어서 전기적 성질과 기계적 성질의 최적화하는데 중요하다.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2609-2615
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• 2013

A series of fluorene-carbazole copolymers containing the pendant phosphor chromophore $Ir(absn)_2(acac)$ (absn: 2-(1-naphthyl)benzothiazole; acac: acetylacetone) were designed and synthesized via Yamamoto coupling. In the film state, these copolymers exhibited absorption and emission peaks at approximately 389 and 426 nm, respectively, which originated from the fluorene backbone. However, in electroluminescent (EL) devices, a significantly red-shifted emission at approximately 611 nm was observed, which was attributed to the pendant iridium(III) complex. Using these copolymers as a single emission layer, polymer light-emitting devices with ITO/PEDOT:PSS/polymer:DNTPD/TmPyPb/LiF/Al configurations exhibited a saturated red emission at 611 nm. The attached iridium(III) complex had a significant effect on the EL performance. A maximum luminous efficiency of 0.85 cd/A, maximum external quantum efficiency of 0.77, maximum power efficiency of 0.48 lm/W, and maximum luminance of 883 $cd/m^2$ were achieved from a device fabricated with the copolymer containing the iridium(III) complex in a 2% molar ratio.

• 폴리머
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• 제35권1호
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• pp.47-51
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• 2011

본 연구는 에폭시의 난연 특성을 향상시키기 위하여 친환경, 저가, 고종횡비(high aspect ratio)를 갖는 무기계 난연첨가재인 일라이트를 사용하였고, 친수성 일라이트의 소수성 에폭시 내 분산 문제점을 개선하기 위하여 불소화 반응을 이용하여 인의 소수화 개질을 실시하였다. 일라이트의 불소화 개질에 의하여 경화 전 에폭시 용액 내에서 일라이트의 분산성 및 경화 후 형성된 복합체 내에서의 일라이트 분산성도 향상되었다. 이러한 분산성의 향상은 일라이트 불소화 개질로 인하여 소수화된 일라이트의 에폭시 용액에 대한 친화성 향상과 복합체 형성 시 에폭시 고분자의 일라이트 층간 삽입 혹은 에폭시에 의한 일라이트의 박리현상 등에 의하여 나타난 현상으로 판단된다. 따라서, 한계 산소 지수(limited oxygen index, LOI)는 일라이트의 불소화 영향으로 에폭시만의 값에 비해 약 24% 정도 증가한 것으로 보아 불소화 일라이트/에폭시 복합제의 제조로 에폭시의 난연 특성을 향상시킬 수 있음을 알 수 있었다.