• Elastomers and Composites
• /
• 제38권2호
• /
• pp.139-146
• /
• 2003

본 연구에서는, 오존 처리에 의한 카본블랙의 표면특성을 X-ray photo-electron spectroscopy (XPS)와 접촉각을 통하여 알아보았으며, 카본블랙/acrylonitrile butadiene rubber (NBR) 복합재료의 기계적 물성은 가교밀도와 인열 에너지 ($G_{IIIC}$)를 측정하여 관찰하였다. 본 실험결과, 오존 처리에 의해 카본블랙 표면에 도입된 산소를 함유한 관능기가 카본블랙의 표면자유에너지를 증가시켰으며, 결과적으로 고무 복합재료의 가교밀도와 인열 에너지가 향상되었다. 이러한 결과는 오존처리에 의해 카본블랙 표면에 도입된 산소를 함유한 관능기가 카본블랙과 고무사이의 계면 결합력을 증가시켜 고무 복합재료의 기계적 물성을 향상시킨 것을 확인할 수 있었다.

• Advances in materials Research
• /
• 제6권1호
• /
• pp.1-12
• /
• 2017

The aim of the work was to evaluate the effect of ultraviolet-ozone ($UV-O_3$) irradiation with different times on the structure and thermal properties of hydroxypropyl methylcellulose (HPMC) in the form of a thin film to be used as bioequivalent materials according to their important broad practical and medical applications. HPMC thin films were exposed to $UV-O_3$ radiation in air at a wavelength of 184.9 nm.The beneficial effects of this treatment on the crystallinity and amorphousity regions were followed by X-ray diffraction technique and FTIR spectroscopy. Differential scanning calorimetry, thermogravimetric and differntial thermal analyses were used in order to study the thermal properties of HPMC samples following the process of photodegradation. The obtained results indicated that the rate of degradation process was increased with increasing the exposure time. Variations in shape and area of the thermal peaks were observed which may be attributed to the different degrees of crystallinity after exposing the treated HPMC samples. This meant a change in the amorphousity of the treated samples, the oxidation of its chemical linkages on its surface and its bulk, and the formation of free radical species as well as bond formation.

• 펄프종이기술
• /
• 제44권1호
• /
• pp.65-73
• /
• 2012

Nowadays, the concern on the environmental load of bleaching process gave rise to the process of ECF(elemental chlorine free) and TCF(total clorine free). These sequences are based on oxygen-derived compounds such as oxygen, ozone, and hydrogen peroxide which is used as a typical eco-friendly bleaching agent. In this study, paper mulberry pulp was bleached with hydrogen peroxide and some bleaching process were accompanied with ultrasonication in order to increase the bleaching efficiency. The best bleaching efficiency of paper mulberry pulp was obtained in the condition of hydrogen peroxide and ultrasonication(20 kHz) bleaching system at $45^{\circ}C$ for 30 min. The brightness and kappa number of paper mulberry pulp were gained to 5.09% and 3.52 respectively. and yield was slightly loosed to 2%. Therefore, the efficiency of hydrogen peroxide and ultrasonication bleaching system of paper mulberry pulp was superior to the conventional hydrogen peroxide bleaching system. Magnesium sulfate acted as a bleaching stabilizer for the increasement of yield. As a result, the yield and viscosity were increased to 2.2% and 12% respectively.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2000년도 추계학술대회논문집
• /
• pp.108-111
• /
• 2000

Bi2212 and Bi2223 thin films are fabricated by ion beam sputtering method. Three phases of Bi2201, Bi2212 and Bi2223 appear as stable ones in spite of the condition for thin film fabrication of Bi2212 and bi2223 compositions, depending on substrate temperature(T$\sub$sub/) and ozone pressure (PO$_3$). It is found out that these phases show similar T$\sub$sub/ and PO$_3$dependence, and that the stable regions of these phases are limited within very narrow temperature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
• /
• pp.308-311
• /
• 2001

Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure( $PO_3$ ). It is found out that these phases show similar $T_{sub}$ and $PO_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 추계학술대회 논문집
• /
• pp.39-42
• /
• 2004

Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature(Tsub) and ozone pressure(PO3). It is found out that these phases show similar Tsub and PO3 dependence, and that the stable regions of these phases are limited within very narrow temperature.

• 한국안전학회지
• /
• 제13권3호
• /
• pp.67-73
• /
• 1998

The technology for neutralizing static electricity by soft X-ray radiation has been newly developed. This technology involves ionization of gas molecules in the vicinity of a charged substrate to generate ions and electrons to reduce electrostatic potential. The ULSI device substrate and liquid crystal display substrate tend to get charged instantly to a high potential level when they are handled in the manufacturing process. Soft X-ray radiation is adequate in air or $O_2$ gas at atmospheric pressure. This newly developed neutralization method is effective to be superior to the conventional technique, i.e., an ionizer by using corona discharge ,in every aspect. The new method features excellent neutralization capability and is able to completely reduce electrostatic potential to 0 V within a short time. Moreover, this is a very clean antistatic technology free from particle generation ,ozone generation, and electromagnetic noise, which are problems in using the corona discharge ionizer.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 추계학술대회 논문집
• /
• pp.308-311
• /
• 2001

Bi-2212 and Bi-2223 thin films are prepared by IBS(ion beam sputtering) technique. Three phases of Bi-2201, Bi-2212 and Bi-2223 appear as stable ones in spite of the conditions for thin film fabrication of Bi-2212 and Bi-2223 compositions, depending on substrate temperature($T_{sub}$) and ozone pressure(PO$_3$). It is found out that these phases show similar $T_{sub}$ and PO$_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 추계학술대회 논문집
• /
• pp.108-111
• /
• 2000

Bi2212 and Bi2223 thin films are fabricated by ion beam sputtering method. Three phases of Bi2201, Bi2212 and Bi2223 appear as stable ones in spite of the condition for thin film fabrication of Bi2212 and bi2223 compositions, depending on substrate temperature(T$\sub$sub/) and ozone pressure (PO$_3$). It is found out that these phases show similar T$\sub$sub/ and PO$_3$ dependence, and that the stable regions of these phases are limited within very narrow temperature.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.589-590
• /
• 2005

BSCCO:2212-2223 thin films were fabricated by using the ion beam sputter with a evaporation method at various substrate temperatures, $T_{sub}$, and ozone gas pressures, $pO_3$. The correlation diagrams of the BSCCO phases with Tsub and $pO_3$ are established in the 2212 and 2223 compositional films. In spite of 2212 compositional sputtering, Bi2201 and Bi2223 as well as Bi2212 phases come out as stable phases depending on Tsub and $pO_3$. From these results, the thermodynamic evaluation of ${\Delta}H$ and ${\Delta}S$, which are related with Gibbs' free energy change for single Bi2212 or Bi2223 phase, was performed.