• Bulletin of the Korean Chemical Society
• /
• 제25권2호
• /
• pp.167-171
• /
• 2004

The electroless deposition of copper on the hydrogen-terminated Si(111) surface was investigated by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, scanning tunneling microscopy (STM), and energy-dispersive spectroscopy (EDS). The hydrogen-terminated Si(111) surface prepared was stable under air atmosphere for a day or more. It was found from ATR-FTIR that two bands centered at 2000 and 2260 $cm^{-1}$ appeared after the H-Si(111) surface was immersed in 40% $NH_4F$ solution containing 10 mM $Cu^{2+}$. On the other hand, STM image included the copper islands with a height of 5 nm and a diameter of 10-20 nm. The EDS data displayed the presence of copper, silicon and oxygen species. The results were rationalized in terms of the redox reaction of surface Si atoms and $Cu^{2+}$ ions in solutions, which are changed into $Si(OH)_x(F)_y$ containing $SiF_6^{2-}$ ions and neutral copper islands.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
• /
• pp.77-77
• /
• 2003

디스플레이 소재나 자동차 글레이징 소재에 있어서 경량화나 충격성을 향상시키기 위하여 플라스틱소재를 기재로 응용하는 연구가 진행되고 있다. 본 연구에서는 폴리에틸렌테레프탈레이트(PET)와 폴리카보네이트(PC) 고분자 필름의 내마모성, Haze 성, 내수증기 차단성 등을 향상시키기 위하여 유기실리콘 전구체인 HMDSO 모노머와 산소를 사용하여 플라즈마 도움화학증착(PECVD) 하였다. RF출력과 HMDSO 투입량, 산소투입량을 변화시키면서 각 증착조건에 따른 생성된 필름의 화학결합구조와 표면조도, 헤이즈 특성에 미치는 영향을 FTIR-ATR, AFM, Hazemeter를 이용하여 알아보았다. HMDSO와 산소를 사용한 박막의 증착은 100 nm/min이상의 높은 증착속도를 가졌고, 증착실험에서 얻은 증착필름의 원소조성을 XPS를 이용하여 구한 결과, 종전의 다른 유기실리콘계 모노머를 사용했을 때보다 효과적으로 박막에 존재하는 탄소잔류물을 감소시키는 것을 확인하였으며, FTIR-ATR결과로 부터 플라스틱 기재의 차이로 인한 생성박막의 결합구조가 다름을 알 수 있었다. 본 연구로부터 HMDSO/02 시스템이 탄소함량이 낮은 박막을 형성시키고 내마모도가 좋은 박막을 증착시키는데 효과적인 것을 알 수 있었다.

• Macromolecular Research
• /
• 제15권6호
• /
• pp.560-564
• /
• 2007

The photostabilization and cure kinetics of UV-curable, optical resins containing various formulations of photostabilizers were investigated to determine the system with the highest cure conversion and durability. Photo-DSC analysis revealed that increasing the concentration of a UV absorber (UVA) decreased both the crosslink density and the cure rate due to competition for the incident photons between the photoinitiator and the UVA, whereas including a hindered amine light stabilizer (HALS) hardly affected either the cure conversion or the cure rate due to its very low absorption of 365 nm. This result was confirmed by FTIR-ATR spectroscopy and UV-visible spectroscopy analyses. QUV ageing experiments showed that the cure conversion and durability were the highest for the UVA/HALS formulation at a ratio of 1 : 2, which is due to their synergistic action.

• Fibers and Polymers
• /
• 제5권1호
• /
• pp.52-58
• /
• 2004

Previous investigation results revealed that after the Low Temperature Plasma (LTP) treatment, the hydrophilicity of wool fiber was improved significantly. Such improvement enhances the wool dyeing and finishing processes which might be due to the changes of the wool surface to a more reactive one. In this paper, wool fibers were treated with LTP with different gases, namely, oxygen, nitrogen and gas mixture (25 % hydrogen/75 % nitrogen). Investigations showed that chemical composition of wool fiber surface varied differently with the different plasma gas used. The surface chemical composition of the different LTP-treated wool fibers was evaluated with different characterization methods, namely FTIR-ATR, XPS and saturated adsorption value. The experimental results were thoroughly discussed.

• Elastomers and Composites
• /
• 제50권1호
• /
• pp.1-6
• /
• 2015

Polybutadiene rubber (BR) has been well known that its physical and chemical properties are changed when it is exposed to ultraviolet light undergoing photooxidation. In this study, photooxdiation process of BR vulcanizate was investigated using a high pressure mercury lamp used as an outdoor lighting, which has high UV radiation efficiency and reasonable cost. Discoloration and crack formation of photooxdized BR vulcanite surface were examined using an image analyzer. Change of chemical functional groups of BR vulcanite surface by photooxidation was investigated using ATR-FTIR, and variation of the crosslink density with the UV irradiation time was investigated. By increasing the UV irradiation time, the crosslink density steeply increased after a period of time and did not increase any more. Formation of hydroxyl (~OH) and carbonyl (~C=O) groups on the BR vulcanizate surface increased and the1,4-cis unit was converted to the 1,4-trans unit as the photooxidation was proceeded.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
• /
• pp.62-65
• /
• 2001

The effects of accelerated UV radiation on EPDM used for a polymeric insulator were investigated by contact angle, surface voltage decay after corona charging, SEM-EDX, ATR-FTIR and XPS. EPDM occurs as loss of hydrophobicity by UV treatment, which followed by surface cracking and chalking. The surface voltage decay on UV-treated EPDM show that the shorter decay time corresponded to the treated samples with a longer UV exposure time. The surface oxygen and aluminum content were found to increase and carbon decrease, as is observed in EDX analysis. The ATR-FTIR and XPS indicated that C-C and C-H groups decreased and the highly oxidized carbon bonds such as C-O, C=O and O-C=O increase with time. Also, the effects of surface charges on hydrophobicity based on our results is discussed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.248-250
• /
• 2004

We have investigated the surface state of 154kV polymeric insulators exposed to in-service conditions for about five years. In order to evaluate surface aging of silicone rubber exposed to real field environments, we used various analytic methods such as contact angle, ATR-FTIR, SEM-EDS. Although contaminants were accumulated on weathershed surface, polymeric insulator has retained its intrinsic surface hydrophocity. In addition, ATR-FTIR confirmed the diffusion layer of a low molecular weight silicone fluid on surface layer and no surface cracking and chalking were Indicated by SEM. Polymeric insulators have still retained their improved pollution performance over porcelain insulators. That will lead to very low frequency of flashovers throughout their useful life, often under contaminated conditions.

• 멤브레인
• /
• 제6권1호
• /
• pp.37-43
• /
• 1996

키토산용액을 다공성폴리술폰 한외여과막에 코팅을 하여 투과증발용 키토산 복합막을 제조하였다. 제조한 키토산 복합막을 디알데히드를 이용하여 화학적으로 가교하여 물-에탄올 혼합물의 투과증발 분리 실험을 행하였다. 화학적가교를 위하여 사용한 알데히드는 글리옥살, 테레프탈알데히드, 글루탈알데히드였으며, 이중 글루탈알데히드가 가장 우수한 가교효과를 나타내었다. 글루알데히드로 표면가교한 키토산 복합막에 대해서 조작온도와 가교조건에 따른 투과증발 성능을 관찰하였다. ATR-FTIR을 이용하여 글루탈알데히드로 표면가교한 키토산 못합막의 가교메카니즘의 고찰과 주사각도를 변화시키면서 표면으로부터의 가교정도 및 열처리에 의한 free 알데히드의 반응을 관찰하였다. 글루탈알데히드로 표면가교를 하는 경우 가교제의 사슬이 유동성을 가지고 있어서 가교시간의 증가에 따라서 선택도는 점차로 증가하다가 감소하여 최적치를 나타내고, 투과유량은 감소하였다.

• 폴리머
• /
• 제35권6호
• /
• pp.605-609
• /
• 2011

전기방사법과 열처리 공정을 통하여 PVDF-$SiO_2$ 복합나노섬유를 제조하였으며, 얻어진 나노섬유는 서로 연결된 기공으로 이루어진 적층 구조를 하고 있었다. 즉, 전기방사로 제조된 나노섬유는 직경이 380 nm, 기공도가 80% 이상인 다공성막을 형성하였다. TEM 사진과 EDX 스펙트라의 분석 결과로부터 $SiO_2$가 나노섬유에 균일하게 분산되어 존재한다는 것이 확인되었다. 또한 전기방사법의 도입에 의해 나노섬유의 기공도가 현저히 개선되었다. ATR-FTIR 및 XRD 분석 결과 복합나노섬유 상에서 PVDF는 ${\alpha}$-phase와 ${\beta}$-phase가 혼재되어 있는 결정구조를 가지고 있었으며, 열처리에 의해서 PVDF의 ${\alpha}$-phase가 증가하였으며, 이로 인해 결정화도가 증가하였다. 특히, 기계적 강도, 열적 특성 및 소수성은 열처리 공정에 의해서 매우 증가되는 것을 확인할 수 있었다.

• 한국수소및신에너지학회논문집
• /
• 제34권3호
• /
• pp.307-315
• /
• 2023

The physical and chemical changes exhibited by high density polyethylene (HDPE) after treatment with hydrogen at a pressure of 90 MPa followed by rapid release of the hydrogen were studied. X-ray diffraction, differential scanning calorimetry, thermo gravimetric analysis, and attenuated total reflectance (ATR)-fourier transform infrared (FTIR) were used for this purpose. As a result, it was found that the degree of crystallinity of HDPE decreased after hydrogen pressure treatment, while the average thickness of lamellae that constitute the crystals and the melting temperature of the crystalline region actually increased. The decomposition temperature also increased by about 3℃. In addition, it was found that the hydrogen bonding network between -OH groups in the HDPE sample was strengthened and partial chain scission occurred. These cut chains were found to be terminated by oxidative degradation such as cross-linking between chains, -C=O, -C-O, and -CHO, or by the formation of -CH₃ at the chain ends, as confirmed by ATR-FTIR.