• 제목/요약/키워드: Chemical bonding

검색결과 1,186건 처리시간 0.024초

지르코니아와 레진 시멘트의 결합 (Bonding to zirconia with resin cements)

  • 임범순;허수복
    • 대한치과의사협회지
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    • 제49권5호
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    • pp.265-278
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    • 2011
  • The introduction of zirconia-based materials to the dental field broadened the design and application limits of, all-ceramic restorations. Most ceramic restorations are adhesively luted to the prepared tooth, however, resin bonding to zirconia components is less reliable than those to other dental ceramic systems. It is important for high retention, prevention of microleakage, and increased fracture resistance, that bonding techniques be improved for zirconia systems. Strong resin bonding relies on micromechanical interlocking and adhesive chemical bonding to the ceramic surface, requiring surface roughening for mechanical bonding and surface activation for chemical adhesion. In many cases, high strength ceramic restorations do not require adhesive bonding to tooth structure and can be placed using conventional cements which rely only on micromechanical retention. However, resin bonding is desirable in some clinical situations. In addition, it is likely that strong chemical adhesion would lead to enhanced long-term fracture and fatigue resistance in the oral environment.

IPA 저온 접합법을 이용한 PMMA Micro CE Chip의 제작 (Fabrication of PMMA Micro CE Chip Using IPA Assisted Low-temperature Bonding)

  • 차남구;박창화;임현우;조민수;박진구
    • 한국재료학회지
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    • 제16권2호
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    • pp.99-105
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    • 2006
  • This paper reports an improved bonding method using the IPA (isopropyl alcohol) assisted low-temperature bonding process for the PMMA (polymethylmethacrylate) micro CE (capillary electrophoresis) chip. There is a problem about channel deformations during the conventional processes such as thermal bonding and solvent bonding methods. The bonding test using an IPA showed good results without channel deformations over 4 inch PMMA wafer at $60^{\circ}C$ and 1.3 bar for 10 minutes. The mechanism of IPA bonding was attributed to the formation of a small amount of vaporized acetone made from the oxidized IPA which allows to solvent bonding. To verify the usefulness of the IPA assisted low-temperature bonding process, the PMMA micro CE chip which had a $45{\mu}m$ channel height was fabricated by hot embossing process. A functional test of the fabricated CE chip was demonstrated by the separation of fluorescein and dichlorofluorescein. Any leakage of liquids was not observed during the test and the electropherogram result was successfully achieved. An IPA assisted low-temperature bonding process could be an easy and effective way to fabricate the PMMA micro CE chip and would help to increase the yield.

고분자 절연체를 이용한 칩투칩 본딩 (Chip-to-chip Bonding with Polymeric Insulators )

  • 오예진;전성우;신진수;류기윤;윤현식
    • 마이크로전자및패키징학회지
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    • 제31권3호
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    • pp.87-90
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    • 2024
  • 현재 3D 집적을 위한 하이브리드 본딩 공정에서 산화물을 절연체로 사용하는 경우 박리가 일어나거나 RC 지연이 증가하는 문제가 발생한다. 본 연구에서는 유전율을 제어할 수 있는 고분자 절연체를 이용한 하이브리드 본딩을 연구하였다. 고분자 계면의 de-wetting 방식의 가능성을 확인하기 위해 기존의 마이크로 범프(micro bump)에 고분자를 코팅 후 열 압착 본딩을 진행하여 금속 사이의 고분자가 빠져나가도록 하였다. 본 연구에서 수행된 하이브리드 본딩의 절연체로 고분자를 도입할 경우, 고분자의 저유전율 특성과 미세 피치 금속 본딩으로 RC 지연을 줄여 신호 전달 속도가 향상될 것으로 사료된다. 또한 차후 이 기술을 하이브리드 본딩에 적용하여 I/O 단자 수가 증가되어 상용화될 것을 기대한다.

지르코니아 수복물의 접착을 위한 임상 가이드 (Clinical Guide for Adhesion of Zirconia Restoration)

  • 황성욱
    • 대한심미치과학회지
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    • 제23권2호
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    • pp.58-69
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    • 2014
  • In case of esthetic restorative procedure with zirconia restoration, we have to use resin cement because of not only just for retention but also esthetic reason. In such a clinical situation, we have to consider two bonding interfaces, one is tooth surface to resin cement and the other is zirconia surface to resin cement. There is well established bonding protocol between tooth surface to resin cement, but bonding protocol of zirconia surface to resin cement is still controversial. In scientific point of view, there are two mechanism for bonding of zirconia restoration.. One is mechanical retention and the other is chemical adhesion. However, we have three different options for bonding of zirconia restoration in clinical situation; 1) Tribo-chemical coating with silica and silane coupling agent 2) Zirconia primer with phosphate chemistry 3) Self-adhesive resin cement with phosphate chemistry.

도재브라켓 접착면의 처리방식이 전단결합강도에 미치는 영향 (EFFECTS OF THE DIFFERENT CERAMIC BRACKET BASES ON SHEAR BOND STRENGTH)

  • 김진오;이기수
    • 대한치과교정학회지
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    • 제24권4호
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    • pp.957-967
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    • 1994
  • The purpose of this study was to evaluate the effects of different bases of ceramic brackets on shear bond strength and to observe failure patterns of bracket bondings. Lower bicuspid brackets whose bases designed for the macromechanical and silane treated chemical bonding those for silane treated chemical bonding, those for micromechanical bonding, and those for macromechanical bonding were tested as experimental groups, and foil mesh-backed metal brackets as a control group. All the brackets were bonded with $Mono-Lok\;2^{(TM)}$ on the labial surface of extracted human lower bicuspids after etching the enamel with $38\%$ phosphoric acid solution for 60 seconds. The shear bond strengths were measured on the universal test machine after 24 hours passed in the $37^{\circ}C$ water bath. The gathered data were evaluated and tested by ANOVA and Duncan's multiple range test, and those results were as follows. The shear bond strengths of brackets for macromechanical and chemical bonding, those for chemical bonding, and those for micromechanical bonding were not different (p>0.05), but showed statistically higher than those of metal bracket and those of ceramic bracket for micromechanical bonding(p<0.05). The shear bond strengths of ceramic bracket for micromechanical bonding showed statistically lower than those of metal bracket(p<0.05). The enamel fractures and/or ceramic bracket fractures were observed in the cases of higher bond strength than that of metal bracket. These results supported that silane treated base of ceramic bracket show higher shear bond strength than that of metal bracket, and suggested that micromechanical form of ceramic bracket bases show higher shear bond strength than that of macromechanical form.

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The Bonding of Interstitial Hydrogen in the NiTi Intermetallic Compound

  • Kang, Dae-Bok
    • Bulletin of the Korean Chemical Society
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    • 제27권12호
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    • pp.2045-2050
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    • 2006
  • The interstitial hydrogen bonding in NiTi solid and its effect on the metal-to-metal bond is investigated by means of the EH tight-binding method. Electronic structures of octahedral clusters $Ti_4Ni_2$ with and without hydrogen in their centers are also calculated using the cluster model. The metal d states that interact with H 1s are mainly metal-metal bonding. The metal-metal bond strength is diminished as the new metal-hydrogen bond is formed. The causes of this bond weakening are analyzed in detail.

Aziridine계 Bonding agent 합성 및 특성연구 (The Synthesis of Aziridine bonding agent and the Study of Characteristics)

  • 양의석;류희진;유광호;손원중;임정온
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2004년도 제23회 추계학술대회 논문집
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    • pp.215-222
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    • 2004
  • 본 논문에서는 고분자의 바인더와 고체불질 사이의 결합력을 증진시켜 물성을 향상시키는 역할과 화학결합에 의한 두 재질간의 접착력을 향상시킬 목적으로 사용되는 Aziridine계 bonding agent를 합성하여 이화학 특성을 분석하고 이를 라이너에 적용하였을 때 불성 및 접착력 특성에 관한 연구를 하였다. 비교 실험을 진행하기 위해 미국 3M사에서 제조한 HX-868을 통일한 조건에서 사용했고 미국규격에 규정된 항목과 각 항목에 대한 표준화된 방법으로 분석하였다. 그 결과 국내기술로 합성한 HX-868이 미국에서 제조된 HX-868과 통일한 품질 수준으로 갖는 것으로 평가되었다.

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