• 한국의류학회지
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• 제20권4호
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• pp.682-689
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• 1996

A preparative method has been proposed for obtaining chitosan products which have a desired degree of deacetylation (DD, %) without much decrease in molecular weight. Deacetylation was prepared by two methods. The method I which was proposed by Domard etc. was that DMSO/thiophenol was used repeatedly only during the deacetylation, the method II was that DMSO/thiophenol was used after the alkali treatment. Then, effective deacetylation was performed by the method ll. To determine the degree of deacetylation, potentiometric titration method was adopted. According to the increase of DD, the viscosity average moleclar weght $(\overline{M\upsilon}$) and the DP of the chitosan products were decreased. The intensity of FT-lR peak appeared at $1655cm^{-1}, which was characteristic peak of amide I (Nacetyl secondary amide group), was gradually decreased with deacetylation. X-ray analysis showed that the lattice-spacing in the chitosan film increased with the degree of deacetylation, but the difference of the transparency of the chitosan products was not diverged significantly.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.45-48
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• 1997

Enhancing the electrical conductivity of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir-Blodgett(LB) technique has recently been attracted interest as the a method of deposition ultrathin films. We have fabricated N-docosyl-N'-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the optical and electrical conductivity. We have measured UV/visible and FT-lR spectrum. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on both temperature and incident angle, which indicates conducting species change. The in-plane electrical conductivity of 21 layers is approximately 1.37$\times$10$^{-6}$ (S/cm).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.152-155
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• 1994

The purpose of this paper is to develope an electron beam resist by the plasma polymerization. Plasma co-polymerized resist was prepared using an interelectrode gas-flow-type reactor. And then delineated pattern in the resist was developed with gas flow type reactor using Ar and O$_2$ gas as etching gas. We study about the effects of discharge power and mixing rate of the copolymerized thin film. The characteristics of molecular structure of thin film was investigated by FT-lR, DSC and GPC, and then was discussed in relation to its quality as a resist.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 추계학술대회 논문집
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• pp.198-201
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• 1994

Stability improvement of fragile LB films was attempted by polyion complexation of monolayers at the air-water interface and crosslinking of the resulting LB films. The spreading polymers were synthesized by radical copolymerization of monoalkyl itaconate with oligoethyleneglycol methyl vinylether, and poly(allylamine) was employed as the subphase polymer. Formation and characteristic of the monolayers were comfirmed by surface pressure-area($\pi$-A) isotherms. The two different polymers formed polyion-complexed monolayer through the formation of carboxylate/ammonium salt at the air-water interface. Y-type deposition occurred on solid substrates, and the transfer ratio was over 0.7. Pores (diameter, 0.1$\mu\textrm{m}$) of a membrane filter could be covered by polyion-complexed 6 layers. Interactions of the polymers with metal ions were investigated of the air-water interface and in the LB films. The structure change and macroscope morphology of the LB films were confirmed by FT-lR and SEM, respective1y.

• 대한의용생체공학회:의공학회지
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• 제8권1호
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• pp.13-28
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• 1987

Crosslinked poly(2-hydroxyethylmethacrylate) has been prepared by polymerizing 2-hydroxyethyl methacrylate(HEMA) with crosslinkers such as ehyleng glycol dime- thacrylate(EGDMA), tetraethylene glycol dimethacrylate(TEGDMA), tetraethylene glycol diacrylate(TEGDA), divinyl benzene(DVB), and N, N-methylenebisacry- lamide(MAB) in the presence of initiator $\alpha$ , $\alpha$ -azobisisobutyronitrile at 60。C, The synthesized copolymers were identified by FT-lR spectrophotomether. The swelling properties of the crosslinked copolymers in various solvents such as water, methanol, ethanol, n-propanol, and n-butanol were investigated at different temperatures. The thermal properties of the crosslinked coplymers were also measured by differential scanning calorimetry(DSC) and thermogravimetry(TG)

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.37-46
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• 1988

Synthetic biodegradable polymers are of great interest for biomedical applications such as surgical sutures and drug delivery systems. The copolymers of ${alpha}-amino$ acids and ${alpha}-hydroxy$ matrices having the required permeability for drugs. Poly (glycine.co-lactic acid) and poly (glycine-co-glycolic acid) have been synthesized by ring-opening polymerization. Morpholine-2, 5-diane, lactide, and glycolid have been used as starting materials for polydepsipeptides. The synthesized monomers and copoylmers have been identified by NMR and FT-lR spectrophotometer. The thermal properties and glass transition temperatures ($T_g$) of the copolymers have been measured by differential scanning calorimetry. The $T_g$ values of poly (glycine-co-lactic acid) and poly (glycine co.glycolic acid) are increased with increasing mole fraction of morpholine-2, 5-dione in the copolymers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.386-388
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• 1996

Low dielectric constant fluorinated oxide (SiOF) films were deposited using SiF$_4$/O$_2$/SiH$_4$mixtures by electron cyclotron resonance chemical vapor deposition (ECR CVD). Chemical composition of SiOF films was investigated by Fourier transform infrared spectroscopy (FT-lR). The fluorine content in the SiOF film observed by X-ray photoelectron spectroscopy (XPS). The dielectric constant decreased with increasing of the SiF$_4$ flow rate about 8sccm. The SiOF film, deposited with SiF$_4$=8 sccm, exhibited a F content of 5 atomic % and a relative dielectric constant 3.45. For evaluating SiOF films stability, humidity tests were performed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.221-224
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• 1996

We synthesized amphiphilic material including dye skeleton, p-phenylenediamine(PD) by attaching norma-decyl group of two strands at a part of coordinating atom, for obtaining reasonable design of LB uniform films. The synthesis of this compounds was quantitatively carried out under ultra pure state. This product was identified with FT-lR spectroscopy, UV absortion spectroscopy, and $^1$H-NMR spectroscopy, respectively. When manufacturing monolayer, we confirmed molecular area from pressure-area($\pi$-A) cutie of thiscompound onto the surface of the water. The spectroscopic approach also has done by UV absortion spectroscopy. It was shown that PD-complex LBfilms were deposited well with monolayer thickness. The conductivity based on I-V characteristics of PD-complex LB films were in the range of 10$^{-10}$ S/cm at room temperture. The microscopic properties by AFM, showed the good orientation of various monolayer or multilayer molecules

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.131-134
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• 1998

This work was carried out to develop a pattern on the nanometer scale using plasma polymerization and plasma etching. This study is also aimed at developing a resist for the nano process and a vacuum lithography process. The thin films of plasma polymerization were fabricated by the plasma po1ymerization of inter-electrode capacitively coupled gas flow system. After delineating the pattern at accelerating voltage of 30[kV]. ranging the dose of 1∼500[${\mu}$C/$\textrm{cm}^2$], the pattern was developed with dry tree and formed by plasma etching. By analysing of the molecule structure using FT-lR, it was confirmed that the thin films of PPMST contains the functional radicals of the MST monomer. The thin films of PPMST had a highly crosslinked structure resulting in a higher molecule weight than the conventional resist.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.454-458
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• 1999

절연재료의 성능 개선과 전력계통의 신뢰성을 확보하기 위해 고분자 재료가 많이 사용되고 있다. 고분자 절연재료는 절연저항 및 절연파괴 강도가 우수하며, 유전손실이 낮고 기계적 강도가 우수하며 대량생산 및 제조가 용이하고, 경량이며 유지비용이 절감되는 등의 장점이 있으나 연구의 역사가 짧고 운전 실적이 적어 불분명한 점이 많으며, 내열성 및 내트랙킹성이 비교적 약하며 표면에 오손이 축적되어 열화가 발생, 진행되거나 수분침투에 의한 파괴사고가 발생하는 단점이 있다. 따라서, 고분자 절연재료의 기본적인 화학적 구조 및 인공적 인 오손 환경을 만들어, 오손 환경의 농도 및 시간대별로 오손환경하에서 우수한 특성을 보이는 샘플을 이용하여 LDPE전체에 대한 실험을 진행했다. 또한 측정법으로서는 화학적인 구조 및 함량을 측정하기 위하여 FT-lR, DSC, TGA를 이용했고, 전기적인 측정으로서는 각각의 조건별로 전도도 및 부분방전특성을 평가하였다.