• 제목/요약/키워드: Au seed

검색결과 33건 처리시간 0.026초

Seed-Mediated Growth of Au Nanoparticles

  • Nguyen, Dung The;Kim, Dong-Joo;Kim, Kyo-Seon
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 추계학술대회 초록집
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    • pp.239-239
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    • 2009
  • We prepared Au nanoparticles by seed-mediated method and investigated the effects of process variables on the seed-mediated growth of Au nanoparticles. The monodispersed Au seed nanoparticles in the size range from 14.3 nm to 20.3 nm were prepared by the reduction reaction between $HAuCl_4$ and citrate. We added the $HAuCl_4$ precursors with citrates into the Au seed solution and prepared the Au nanoparticles in the size range from 16.8 and 37.8 nm with monodisperse distribution and could control the size of Au nanoparticles by changing the amount of $HAuCl_4$ precursor.

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Post-Annealing Effects on Properties of ZnO Nanorods Grown on Au Seed Layers

  • Cho, Min-Young;Kim, Min-Su;Choi, Hyun-Young;Yim, Kwang-Gug;Leem, Jae-Young
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.880-884
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    • 2011
  • ZnO nanorods were grown by hydrothermal method. Two kinds of seed layers, Au film and island seed layers were prepared to investigate the effect of seed layer on ZnO nanorods. The ZnO nanorod on Au island seed layer has more unifom diameter and higher density compared to that of ZnO nanorod on Au film seed layer. The ZnO nanorods on Au island seed layer were annealed at various temperatures ranging from 300 to $850^{\circ}C$. The pinholes at the surface of the ZnO nanorods is formed as the annealing temperature is increased. It is noted that the pyramid structure on the surface of ZnO nanorod is observed at $850^{\circ}C$. The intensity of ZnO (002) diffraction peak in X-ray diffraction pattern and intensity of near band edge emission (NBE) peak in photoluminescence (PL) are increased as the ZnO nanorods were annealed at the temperature of $300^{\circ}C$.

Electrochemical Synthesis of Dumbbell-like Au-Ni-Au Nanorods and Their Surface Plasmon Resonance

  • Park, Yeon Ju;Liu, Lichun;Yoo, Sang-Hoon;Park, Sungho
    • Journal of Electrochemical Science and Technology
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    • 제3권2호
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    • pp.57-62
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    • 2012
  • In this report, we demonstrate that the longitudinal localized surface plasmon resonance mode can be suppressed when the nanorods were in dumbbell shape. The seed nanorods were synthesized by electrochemical deposition of metals into the pores of anodic aluminum oxide templates. The dumbbell-like nanorods were grown from seed Au-Ni-Au nanorods by a rate-controlled seed-mediated growth strategy. The selective deposition of Au atoms onto Au blocks of Au-Ni-Au nanorods produced larger diameter of Au nanorods with bumpy surface resulting in dumbbell-like nanorods. The morphology of nanorods depended on the reduction rate of $AuCl_4^-$, slow rate producing smooth surface of Au nanorods, but high reduction rate producing bumpy surface morphology. Through systematic investigation into the UV-Vis-NIR spectroscopy, we found that the multiple localized surface plasmon resonance (LSPR) modes were available from single-component Au nanorods. And, their LSPR modes of Au NRs with bumpy surface, compared to the smooth seed Au NRs, were red-shifted, which was obviously attributed to the increased electron oscillation pathways. While the longitudinal LSPR modes of smoothly grown Au NRs were blue-shifted except for a dipole transverse LSPR mode, which can be interpreted by decreased aspect ratio. In addition, dumbbell-like nanorods showed an almost disappeared longitudinal LSPR mode. It reflects that the plasmonic properties can be engineered using complex nanorods structure.

강원도 중왕산 지역에서 부게꽃나무의 개화, 결실, 종자낙하량 및 종자활력 (Flowering, Fruiting, Seed Fall and Seed Viability of Acer ukurunduense in Mt. Jungwang, Gangwondo)

  • 김갑태;김회진
    • 한국산림과학회지
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    • 제103권2호
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    • pp.153-158
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    • 2014
  • 천연활엽수림의 천연갱신 가능성을 파악하고자, 부게꽃나무(Acer ukurunduense Trautv. & C.A. Mey.)의 개화 결실, 종자낙하, 종자활력을 강원도 평창군 중왕산 지역에서 2009년부터 2013년까지 조사하였다. 부게꽃나무 꽃은 총 상화서(드물게 원추화서)에 양성화와 웅성화가 많이 달렸으며, 꽃의 배열은 화서마다 서로 달랐다. 화서 내에서 성형태간 개화시기가 달랐다. 양성화로 암술이 수분되어 자라기 시작한 꽃에서는 수술은 더 이상 성숙하지 않고 소실되었으며, 수술이 발달한 꽃에는 암술은 흔적으로만 존재하였다. 부게꽃나무는 꿀벌, 깜둥이창나방, 하늘소류, 애꽃벌류, 대모각다귀류 등이 수분하며, 자가수분을 회피하는 기작을 가지고 있다고 사료된다. 화서당 꽃의 수는 6월 8일에 189개였다가, 6월 21에는 과수당 시과?의 수는 41.2개였으며, 9월 5일에는 과수당 33.4개로 줄어들었다. 시과낙하량은 670~17,930 ea/ha의 범위로 평균은 6,720 ea/ha이었다. 건전배를 가진 것이 43.2%로 가장 많았고, 다음으로 피해 부후인 것이 41.8%, 미발육 10.2%, 쭉정이배 4.8%로 나타났다. 건전종자 생산량을 좌우하는 요인은 개화기인 6월 초순에 화분매개충의 활동과 어린 자방이 자라는 6월 초 중순 흡즙성 해충의 밀도와 활동성이 가장 중요한 요인이라 사료된다. 부게꽃나무의 천연갱신은 종자다산해에 발아와 생장에 유리한 조건을 갖춘 갭에서 이루어질 것으로 사료된다. 단풍나무류의 천연갱신을 이해하기 위해서 종자결실과 비산전 후 종자피식 문제에 대한 장기간의 연구가 필요할 것이라 사료된다.

Synthesis of Trimetallic Au@Pb@Pt Core-shell Nanoparticles and their Electrocatalytic Activity toward Formic Acid and Methanol

  • Patra, Srikanta;Yang, Hae-Sik
    • Bulletin of the Korean Chemical Society
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    • 제30권7호
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    • pp.1485-1488
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    • 2009
  • A facile, seed-mediated preparation method of trimetallic Au@Pb@Pt core-shell nanoparticles is developed. Au nanoparticles are the template seeds onto which sequentially reduced Pb and Pt are deposited. The trimetallic core-shell structure is confirmed by UV-Vis spectroscopy, TEM and EDS analysis, and cyclic voltammetry. The trimetallic Au@Pb@Pt core-shell nanoparticles show high electrocatalytic activity for formic acid and methanol electrooxidation.

천연갱신과 관련된 한국산 단풍나무속 6종의 종자특성과 종자활력에 관한 연구 (Studies on the Seed Characteristics and Viabilities of Six Acer Species in Relation to Natural Regeneration in Korea)

  • 김갑태;김회진
    • 한국환경생태학회지
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    • 제25권3호
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    • pp.358-364
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    • 2011
  • 단풍나무류의 활력있는 종자의 공급량을 파악해 보고자, 2009년과 2010년의 초가을에 단풍속 6수종, 복장나무, 고로쇠나무, 우산고로쇠, 부게꽃나무, 당단풍 및 단풍나무 종자를 채취하여 종자특성과 종자활력을 조사하였다. 화서형태는 복장나무, 당단풍과 단풍나무는 산방화서(corymb), 고로쇠나무와 우산고로쇠는 위가 편평한 원추화서(flat-topped panicle), 부게꽃나무는 총상화서(raceme)였다. 화서당 종자�V의 개수는 부게꽃나무가 38.5개로 가장 많았고, 당단풍이 2.4개로 가장 적었다. 종자직경은 우산고로쇠가 13.5mm로 가장 크고, 당단풍이 4.7mm로 가장 작았다. 시과의 각도는 당단풍이 $130.05^{\circ}$로 가장 크고, 부게꽃나무가 $48.60^{\circ}$로 가장 작았다. 20 시과�V의 건조중량은 우산고로쇠가 3,900mg으로 가장 무거웠고, 부게꽃나무가 404mg으로 가장 가벼웠다. 채종한 단풍나무류 종자의 건전종자의 비율은 단풍나무는 50%, 다음으로 부게꽃나무는 43.2%로 나타났다. 나머지 4 수종은 8.6~22.2% 정도로 나타나, 낙하종자에 대한 설치류의 피식량, 건조의 피해, 낙엽층의 발아방해 등을 고려하면 고로쇠, 우산고로쇠 복장나무, 당단풍나무 등의 천연갱신이 잘 이루어지지 않는 것이 건전종자의 공급량 부족이 하나의 원인일 수 있을 것이라 사료된다. 고로쇠, 우산고로쇠, 부게꽃나무 및 당단풍나무의 종피에서 벌레에 의한 천공피해가 관찰되었으며, 고로쇠나무와 우산고로쇠의 종자에서는 검정긴꽃바구미(Bradybatus sharpi)가 공통적으로 관찰되었다. 단풍나무류의 천연갱신을 이해하기 위해서 종자결실과 비산전 후 종자피식 문제에 대한 장기간의 연구가 필요할 것이라 사료된다.

Silicon wafer via 상의 기능성 박막층 종류에 따른 Cu filling 특성 연구 (Study of Cu filling characteristic on Silicon wafer via according to seed layer)

  • 김인락;이왕구;이영곤;정재필
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 추계학술대회 초록집
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    • pp.171-172
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    • 2009
  • TSV(through via silicon)를 이용한 Via의 Cu 충전에서 Seed 층의 역할은 전류의 흐름을 가능하게 하는 중요한 역할을 하고 있다. Via에 각각 Ti/Au, Ti/Cu를 증착한 후 Ti/Cu가 Ti/Au를 대체 할 수 있는지를 알아보기 위해 먼저 실리콘 웨이퍼에 via를 형성하고, 형성된 via에 기능성 박막층으로 절연층(SiO2) 및 시드층을 형성하였다. 전해도금을 이용하여 Cu를 충전한 결과 Ti/Au 및 Ti/Cu를 증착한 두 시편 모두 via와 seed층 접합면에 박리 등의 결함이 없었고, via 내부 또한 void나 seam 등이 관찰되지 않고 우수하게 충전된 것을 확인할 수 있었다.

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Growth Behavior of Ga-Doped ZnO Thin Films on Au/SiNx/Si(001) Substrate Grown by RF Sputtering

  • 김주현;이무성;강현철
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.463-463
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    • 2013
  • This paper reports the synthesis and characterization of ZnO:Ga nano-structures deposited on Au/SiNx/Si(001) by radio-frequency sputtering. The effect of the temperature on the microstructure of the as-grown ZnO:Ga thin films was examined. The growth mode of ZnO:Ga nano-structures can be explained by the profile coating, i.e. the ZnO nano-structures were formed with a morphological replica of Au seeds. Initially, the ZnO:Ga nano-structures were overgrown on top of Au nano-crystals. Small ZnO:Ga nano-dots were then nucleated on hexagonal ZnO:Ga discs.

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Mirepoix Au Maigre 함량 수준에 따른 포도씨유 드레싱의 수용도 변화 (Changes in Preference for Grape Seed Oil Dressing according to Mirepoix au Maigre Content Level)

  • 유승석;서민석
    • 한국식품조리과학회지
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    • 제23권5호
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    • pp.685-695
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    • 2007
  • The purpose of this study was to develop an excellent salad dressing using grape seed oil, which contains high levels of unsaturated fatty acids. First, a vinaigrette was made with grape seed oil and vinegar and divided into five portions. Then, five types of mirepoix au maigre ($M_1,M_2,M_3,M_4,M_5$) were made with apple, onion, carrot, garlic, tomato puree, and tomato ketchup by mixing in a main material vessel. The samples were then allowed to ripen for three days. The control group $M_1$ was named $GD_1$, and the experimental groups $M_2,\;M_3,\;M_4,\;and\;M_5$ were named $GD_2,\;GD_3,\;GD_4,\;and\;GD_5$. respectively. To measure receptiveness, a sensory test was conducted using a 7 point category scale. The test concentrated on flavor, taste, color, agreeability, aftertaste, and overall acceptability: the panel consisted of 15 subjects According to the results, $GD_4$ had the best flavor, color and agreeability. The samples with the most preferred taste and aftertaste were $GD_4\;and\;GD_5$. Between $GD_4\;and\;GD_5$, there were no noticeable differences in taste, aftertaste, or overall acceptability, but differences in color and agreeability did exist. Thus, $GD_4$ proved to be the most favorable product. To determine the best complementing vegetables for $GD_4$ yam($VE_1$), broccoli sprouts($VE_2$), mustard leaves($VE_3$), beet leaves($VE_4$), cucumber($VE_5$), and lettuce(VE6) were selected as samples, and a sensory test was conducted. Each vegetable has its own peculiarities. According to the results, $VE_2$ had the nicest vegetable fragrance recording the highest mean value. The vegetable with the most preferred taste, aftertaste, and agreeability were $VE_2\;and\;VE_6$. $VE_1\;and\;VE_6$ had the nicest color and contained the brightest color as well. The highest overall acceptability was awarded to $VE_2\;and\;VE_6$ and there was no remarkable difference between thorn at a level of 0.05. In conclusion, $VE_2\;and\;VE_6$ were the best complementing vegetables with grape seed oil dressing. However, to commercialize such a dressing, many follow-up studies must be conducted.

LIFT 방법에 의한 전도성 미세 패터닝 공정 연구 (Micro patterning of conductor line by laser induced forward transfer(LIFT))

  • 이제훈;한유희
    • 한국레이저가공학회지
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    • 제2권3호
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    • pp.52-61
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    • 1999
  • The laser induced forward transfer(LIFT) technique employs a pulsed laser to transfer parts of a thin metal film from an optically transparent target onto an arbitrary substrate in close proximity to the metal film on the target. In this work, a two-step method, the combination of LIFT process, in which a Au film deposited on the $Al_2$O$_3$ substrate by Nd:YAG laser and subsequent Au electroless metal plating on the by LIFT process generated Au seed, was presented. The influence of laser parameters, wavelength, laser power, film thickness and overlap ratio of pulse tracks, on the shapes of deposit and conductor line after electroless plating is experimentally studied. As a results, the threshold power densities for ablation, deposition and metallization were determined and comparison of threshold value between the wave length 1064nm and the second harmonic generated 532nm. In odor to determine a possible application in the electronic industry, a smallest conduct spot size, line width and isolated line space were generated.

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