• 제목/요약/키워드: Nano Oxide

검색결과 1,163건 처리시간 0.063초

AC전압 인가에 따른 알루미늄 양극산화 공정 및 박막 특성

  • 이정택;최재호;김근주
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
    • /
    • pp.242-242
    • /
    • 2009
  • Fabrication of Anodic aluminum oxide under DC vias condition has been studied. When bias and time of anodic aluminum oxide process change, the hole distance and diameter size change. Comparison of fabricated AAO between AC vias and DC vias condition has been studied in this experiment. The first and second anodization of one aluminum is done by using DC and AC power supplier. And first and second anodization of another aluminum is done by DC power supplier. The size of the aluminum is $1cm{\times}3cm$, and second anodic aluminum oxide process takes about 45min. It is found that the hexagonal shape appears on the surface of the AAO. AC power source can fabricate aao which have a nano hole array. We can see that the hole on the surface of the AC vias has a better rounded hole than DC vias AAO. we need more data so we can get characteristic about AC power generated AAO.

  • PDF

Hydrophilic Modification of Poly(ethylene oxide) by UV Irradiation

  • Koo, Gwang-Hoe;Jang, Jin-Ho
    • 한국염색가공학회지
    • /
    • 제21권5호
    • /
    • pp.16-20
    • /
    • 2009
  • Films of Poly(ethylene oxide), PEO, were modified to impart hydrophilicity via UV irradiation. The UV irradiation treatment produced new photo-oxidized groups of carbonyl and ether groups as indicated in ATR and ESCA analysis. It was found that water contact angle decreased from $15^{\circ}C$ to $10^{\circ}C$ and total surface energy of PEO increased from 54.2 mN/m to 76.6 mN/m with increasing UV energy, which was attributed to significant contribution of acid base interaction of the photo-oxidized PEO rather than nonpolar interaction originating from the dominant increase in Lewis acid parameter. The increased hydrophilicity and surface energy were also proved by the decreased water wetting time.

Facile and Ecofriendly Fluorination of Graphene Oxide

  • Yadav, Santosh Kumar;Lee, Jin Hong;Park, Hun;Hong, Soon Man;Han, Tae Hee;Koo, Chong Min
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권7호
    • /
    • pp.2139-2142
    • /
    • 2014
  • A one-pot, facile and ecofriendly approach to the fabrication of covalently fluorinated graphene using mild reaction conditions is reported. This straightforward and efficient strategy allows fluorine groups to be covalently and stably anchored onto graphene to produce single-layer functionalized graphene sheets from a graphene oxide precursor.

수열처리에 의한 세리아가 코팅된 실리카 연마재의 제조 및 Oxide Film의 연마특성 (Preparation of Ceria Coated Silica Abrasive by Hydrothermal Treatment and Polishing Rate on Oxide Film)

  • 유대선;김대성;이승호
    • 한국재료학회지
    • /
    • 제15권12호
    • /
    • pp.818-823
    • /
    • 2005
  • Sub-micron colloidal silica particles coated with nano-sized ceria were prepared by mixing of its silica and cerium salts hydrolysis, and modified by hydrothermal reaction. By using the slurries with and without hydrothermal modification containing above particles, oxide film coated on silicon wafer was polished. The modified slurries had higher polish rate due to increase of ceria fraction to silica through hydrothermal reaction. They revealed higher stability in wide range of pH $2\~10$ than ceria coated silica slurries without its modification.

상온에서 RF 스퍼터링 방법으로 증착한 Hafnium Oxide 박막의 저항 변화 특성 (Resistive Switching Characteristics of Hafnium Oxide Thin Films Sputtered at Room Temperature)

  • 한용;조경아;윤정권;김상식
    • 한국전기전자재료학회논문지
    • /
    • 제24권9호
    • /
    • pp.710-712
    • /
    • 2011
  • In this study, we fabricate resistive switching random access memory (ReRAM) devices constructed with a Al/$HfO_2$/ITO structure on glass substrates and investigate their memory characteristics. The hafnium oxide thin film used as a resistive switching layer is sputtered at room temperature in a sputtering system with a cooling unit. The Al/$HfO_2$/ITO device exhibits bipolar resistive switching characteristics, and the ratio of the high resistance (HRS) to low resistance states (LRS) is more than 60. In addition, the resistance ratio maintains even after $10^4$ seconds.

Physicochemical properties of a calcium aluminate cement containing nanoparticles of zinc oxide

  • Amanda Freitas da Rosa;Thuany Schmitz Amaral;Maria Eduarda Paz Dotto;Taynara Santos Goulart;Hebert Luis Rossetto;Eduardo Antunes Bortoluzzi;Cleonice da Silveira Teixeira;Lucas da Fonseca Roberti Garcia
    • Restorative Dentistry and Endodontics
    • /
    • 제48권1호
    • /
    • pp.3.1-3.14
    • /
    • 2023
  • Objectives: This study evaluated the effect of different nanoparticulated zinc oxide (nano-ZnO) and conventional-ZnO ratios on the physicochemical properties of calcium aluminate cement (CAC). Materials and Methods: The conventional-ZnO and nano-ZnO were added to the cement powder in the following proportions: G1 (20% conventional-ZnO), G2 (15% conventional-ZnO + 5% nano-ZnO), G3 (12% conventional-ZnO + 3% nano-ZnO) and G4 (10% conventional-ZnO + 5% nano-ZnO). The radiopacity (Rad), setting time (Set), dimensional change (Dc), solubility (Sol), compressive strength (Cst), and pH were evaluated. The nano-ZnO and CAC containing conventional-ZnO were also assessed using scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Radiopacity data were analyzed by the 1-way analysis of variance (ANOVA) and Bonferroni tests (p < 0.05). The data of the other properties were analyzed by the ANOVA, Tukey, and Fisher tests (p < 0.05). Results: The nano-ZnO and CAC containing conventional-ZnO powders presented particles with few impurities and nanometric and micrometric sizes, respectively. G1 had the highest Rad mean value (p < 0.05). When compared to G1, groups containing nano-ZnO had a significant reduction in the Set (p < 0.05) and lower values of Dc at 24 hours (p < 0.05). The Cst was higher for G4, with a significant difference for the other groups (p < 0.05). The Sol did not present significant differences among groups (p > 0.05). Conclusions: The addition of nano-ZnO to CAC improved its dimensional change, setting time, and compressive strength, which may be promising for the clinical performance of this cement.