• Macromolecular Research
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• 제11권6호
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• pp.437-443
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• 2003

A series of alternating and alternating block copolycarbonates containing the constituent groups of polysulfone was synthesized through a multi-step solution condensation method. For the regulation of block length, monodisperse oligomers were prepared by using a large excess of the bisphenols and were subsequently incorporated into the copolymer chains. Separating the unreacted bisphenols from the oligomers by dissolution/precipitation steps took advantage of solubility differences. The structures of the monomers, oligomers, and copolymers were characterized and confirmed by GPC, NMR spectroscopy, mass spectrometry, and elemental analysis. Monodispersity of the oligomers, which is critical for control over the block length in the copolymers, was confirmed by GPC and mass spectrometry. Of the two constituent groups of the polysulfone, the sulfone linkage stiffens the polycarbonate copolymer chain, while the ether linkage softens it.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.406.3-407
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• 2002

Analysis of interferon alpha (IFN) modified with high molecular weight branched PEG was performed by capillary electrophoresis (CE) and MALDI-TOF mass spectrometry (MALDI-TOF MS). IFN was modified by the reaction of amine residues with an active ester of monomethoxy polyethylene glycol at various molar ratios. As a CE method. capilary electrophoresis sodium dodecyl sulfate nongel sieving (CE-SDS NGS) was performed using an uncoated capilary filled with a hydrophilic replaceable polymer network matrix. (omitted)

• 한국표면공학회지
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• 제29권6호
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• pp.880-883
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• 1996

Plasma Source Ion Implantation (PSII) technique was used for the hydrophilization or hydrophobization of polymer surfaces. Polymers were modified with different plasma gases such as oxygen, nitrogen, argon, and tetrafluoromethane, and for varying lengths of treatment time. Plasma ion treatment of oxygen, nitrogen, argon and their mixtures increased significantly the hydrophilic properties of polymer surfaces. More hydrophobic surfaces of polymers were formed after the treatment with tetrafluoromethane. A study of plasma source ion implanted polymers was performed using contact angle measurements and Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). The TOF-SIMS spectra and depth profile were used to obtain the information about the treated surfaces of polymers. The permanence of this technique could be evaluated with respect to ageing time. The surfaces treated with PSII gave better stability than other surface modification methods.

• 한국표면공학회지
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• 제32권2호
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• pp.93-99
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• 1999

Surface polymer layer formed on the silicon wafer during the oxide overetching using $C_4F_8$/ helicon wave plasmas and their characteristics were investigated using spectroscopic elipsometry, X-ray photoelectron spectroscopy, and secondary ion mass spectrometry. Overetch percentage and dc-self bias voltage were varied to investigate the effects on the characteristics of the polymers remaining on the overetched silicon surface. The increase of bias voltage from -80 volts to -120 volts increased the C/F ratio and carbon bondings such as C-C, $C-CF_x$/, and C-Si in the polymer while reducing the thickness of the polymer layer. However, the increase of the overetch percentage from 50% to 100% did not change the composition of the polymer layer and the carbon bondings in the polymer layer remained same even though it increased the polymer thickness. The polymer layer formed at the higher dc-self bias voltage was more difficult to be removed by the following various post-etch treatments compared to that formed at the longer overetch percentage.

• 대한화학회지
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• 제7권2호
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• pp.106-114
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• 1963

The products from polymer pyrolysis at $450^{\circ}$ are cooled with ice, then liquid and gaseous portions are analysed by gas chromatography. Di-2-ethyl hexyl sebacate column, silicone oil column, silica gel column and tetraethyleneglycol dimethylether column, which was most effective for the separation of hydrocarbon gases, are used. Identification of isomers could be secured more effectively by gas chromatography than mass spectrometry. Elucidation of the mechanism for thermal decomposition of polymers could be done through the identification of pyrolysis products. Although more extensive work is needed, some patterns of polymer pyrolysis are discussed.

• 한국진공학회지
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• 제6권4호
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• pp.321-325
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• 1997

LCD용 칼라 필터를 제작하는 방법으로 감광성 고분자(photosensitive polymer)에 광 리소그라피(photolithography)기술이 많이 이용되어지고 있다. 이로 인해 감광성 고분자 표 면의 물리적, 화학적 성질이 변하게 되는데, 이는 후속 공정인 플라즈마 식각이나 ITO 전극 의 증착 등에도 많은 영향을 주므로, 각 공정에 따른 이들 고분자의 표면 연구는 매우 중요 하다. 본 논문에서는 blue 칼라 필터의 고분자 표면에 대한 연구를 SIMS와 XPS를 이용하 여 수행하였으며, 표면의 거칠기 변화를 AFM을 통해 관찰하였다. SIMS와 XPS결과로부터 초기 공정인 blue 칼라 필터를 스핀 코팅하고 pre bake한 상태에서는 주로 칼라 필터의 주 성분인 단량체와 결합제의 고분자 물질이 표면에 드러나 있다가, 노광 과정을 거치고 post bake한 시료에서는 색깔을 내는 안료 성분이 표면에 드러남을 확인하였고, AFM을 통해서 는 post bake후에 표면에 더 거칠어 짐을 관찰하였다.

• 한국화재소방학회논문지
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• 제27권2호
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• pp.70-74
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• 2013

화재 현장에서 수집된 화재증거물은 신뢰성 있는 용기에 수집, 보관 되어 감정기관으로 제공되어야 한다. 본 연구에서는 인화성 물질 5종(톨루엔, 노말옥탄, o-자일렌, 노말데칸, 노말헥사데칸)의 장판화재 증거물과 10 ${\mu}L$의 인화성 물질 5종을 적신 킴와이프스 종이를 4가지 용기(금속캔, 유리병, 나일론 지퍼백, 나일론 실링 백)에 두고, 온도 및 보관 기간에 따라 보관한 후 시료 속의 인화성 물질 잔존 유무를 가스크로마토그래프/질량분석기를 이용하여 확인하였는데, 그 결과 테프론이 코팅된 마개를 가진 유리병의 경우가 $60^{\circ}C$에서 22일 동안 보관하여도 5종의 화학물질이 검출이 가능하여, 유리병이 보관 성능이 가장 우수함을 확인하였다.

• Macromolecular Research
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• 제16권2호
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• pp.108-112
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• 2008

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis of nonpolar polymeric materials is affected by the sample preparation as well as the matrix and cationizing agent. This study examined the influence of silver salt types on the MALDI analysis of polybutadiene (PB). Silver trifluoroacetate (AgTFA), silver benzoate (AgBz), silver nitrate ($AgNO_3$), and silver p-toluenesulfonate (AgTS) were used as the silver salts to compare the MALDI mass spectra of PB. The mixture solution of PB and 2,5-dihydroxybenzoic acid (DHB), as a matrix dissolved in THF, was spotted on the sample plate and dried. A droplet of the aqueous silver salt solution was placed onto the mixture. The mass spectrum with AgBz showed the clear $[M+Ag]^+$ ion distribution of PB while the mass spectrum with AgTFA did not show $[M+Ag]^+$ ions but only silver cluster ions. The mass spectra with $AgNO_3$ and AgTS did not show a clear $[M+Ag]^+$ ion distribution. The difference in the formation of $[M+Ag]^+$ ions of PB depending on the silver salts was attributed to the silver cation transfer reaction between the silver salt and the matrix (DHB). The mass spectrum showed a clear $[M+Ag]^+$ ion distribution of PB when the conjugate acid of the silver salt was less acidic than the matrix.

• Macromolecular Research
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• 제9권2호
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• pp.100-106
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• 2001

Several star-polymers with aliphatic cores were synthesized by ring opening polymerization (ROP) of $\xi$-caprolactone using stannous 2-ethyl-hexanoate as a catalyst. The star-polymers were thoroughly analyzed by MALDI-TOF mass spectrometry, temperature gradient interaction chromatography and $\^$13/C-NMR to obtain detailed information of the molecular structure. The imperfection of the star-polymers seemed to be originated from restricted participation of sterically hindered hydroxyl groups of initiator. The synthesized star-polymers had narrow molecular weight distributions. Various reaction conditions to control the imperfection were studied.

• 한국염색가공학회지
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• 제34권2호
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• pp.77-92
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• 2022

Natural colorants are regarded as substitutes for synthetic colorants in the fields of fiber dyeing, hair dyeing, cosmetic, and food industries. The use of natural colorants has been increased in view of global environment and sustainability. However, scientific approach to the production is required because the supply of natural colorants depends on the climate, soil, and cultivation methods. This brief review contains the advances in science and technology related to natural colorants including characterization, analysis, CIEL^*a^*b^* and Munsell color systems, and future prospects. For the characterization and the analysis of natural colorants, chromatography, some spectroscopic techniques (UV-Vis, FT-IR, NMR), mass spectrometry, and X-ray diffraction are generally used.