• Title/Summary/Keyword: Metal Nanoparticle

Search Result 196, Processing Time 0.024 seconds

Toxicity Evaluation of Metals and Metal-oxide Nanoparticles based on the Absorbance, Chlorophyll Content, and Cell Count of Chlorella vulgaris (Chlorella vulgaris의 흡광도, 클로로필 및 개체수 통합 영향에 근거한 중금속 및 나노입자 독성 조사)

  • Jang, Hyun Jin;Lee, Mun Hee;Lee, Eun Jin;Yang, Xin;Kong, In Chul
    • Clean Technology
    • /
    • v.23 no.1
    • /
    • pp.27-33
    • /
    • 2017
  • In this study, toxicities of seven metals (Cu, Cd, Cr, As(III), As(V), Zn, Ni) and five metal oxide nanoparticles (NPs: CuO, ZnO, NiO, $TiO_2$, $Fe_2O_3$) were evaluated based on the growth of Chlorella vulgaris. Effect on algae growth was evaluated by integrating the results of absorption, chlorophyll content, and cell count. The toxicity rankings of metals was observed as Cr ($0.7mgL^{-1}$) > Cu ($1.7mgL^{-1}$) > Cd ($3.2mgL^{-1}$) > Zn ($3.9mgL^{-1}$) > Ni ($13.2mgL^{-1}$) > As(III) ($17.8mgL^{-1}$) ${\gg}$ As(V) (> $1000mgL^{-1}$). Slightly different orders and sensitivities of metal toxicity were examined depending on endpoints of algal growth. In case of NPs, regardless of endpoints, similar toxicity rankings of NPs ($TEC_{50}$) were observed, showing ZnO ($2.4mgL^{-1}$) > NiO ($21.1mgL^{-1}$) > CuO ($36.6mgL^{-1}$) > $TiO_2$ ($62.5mgL^{-1}$) > $Fe_2O_3$ ($82.7mgL^{-1}$). These results indicate that an integrating results of endpoints might be an effective strategy for the assessment of contaminants.

Wettability of SAC305-coated Cu Fabricated by Low Temperature Process Using Ultrafine SAC305 Nanoparticles (초미세 SAC305 나노입자를 사용한 저온 코팅법으로 제조된 SAC305 코팅 Cu의 솔더 젖음성)

  • Shin, Yong Moo;Choi, Tae Jong;Cho, Kyung Jin;Jang, Seok Pil;Lee, Jong-Hyun
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.22 no.3
    • /
    • pp.25-30
    • /
    • 2015
  • SAC-coated Cu specimens were fabricated by novel pad finish process using a phenomenon that metal nanoparticles less than 20 nm in diameter melted at a temperature lower than the melting point of bulk metal, and their wettabilities were evaluated. The thickness of SAC305 layer coated at low temperature of $160^{\circ}C$ using SAC305 ink was extremely thin as the level of several nanometers. It was analyzed by Auger electron spectroscopy that $Cu_6Sn_5$ intermetallic layer with a thickness of 10~100 nm and $Cu_3Sn$ intermetallic layer with a thickness of 50~150 nm were sequentially formed under the SAC305 coating layer. The thickness of formed intermetallic layers was thicker in electroplated Cu than rolled Cu, which attributed to improved surface roughness in the electroplated Cu. The improved surface roughness induces the contact, melting, and reaction of a larger number of SAC305 nanoparticles per the unit area of Cu specimen. In the wetting angle test using SAC305 solder balls, the Cu coated with SAC305 through the low temperature process presented evidently low wetting angles than those in non-coated Cu, indicating that only a few nanometer-thick SAC305 coating layer on Cu could also cause the enhancement of wettability.

수처리 목적의 대기압플라즈마를 이용한 유사 폴리도파민 필름 증착

  • Mun, Mu-Gyeom;Yeom, Geun-Yeong
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2018.06a
    • /
    • pp.124-124
    • /
    • 2018
  • Polydopamine은 수중 접착력, 친환경 접착제, nanoparticle absorption 등 다양한 특성으로 많이 연구되고 있는 소재이다. 본 연구에서는 dopamine을 이용하여 수중 금속을 흡착시키는 thin film을 제작하였다. 종래의 Polydopamine coating 방법으로 wet coating 이 사용되고 있다. 하지만 wet 방식의 경우 시간이 오래 걸릴 뿐만 아니라 in-line, roll to roll 방식을 적용하는 것이 어렵기 때문에 생산적이지 않다. 이에 본 연구에서는 Atmospheric Pressure Plasma(APP)를 이용 하여 Polydopamine-like film을 coating 하였다. APP의 경우 vacuum system, solution tank가 필요 없고 in-line, roll to roll 방식을 적용 할 수 있기 때문에 더 경제적이고 생산적인 공정이다. 또한 기존의 Plasma polymerization 방법은 Plasma energy가 높기 때문에 source의 분자구조가 바뀌거나 atom 단위로 분해된다. source의 분자구조가 바뀌는 "Atomic polymerization", Neiswender-Rosskamp Mechanism이 적용되면 wet 방식 coating한 film과는 다른 특성을 갖게 된다. 하지만 APP polymerization은 Plasma energy가 vacuum plasma 보다 매우 낮기 때문에 stile polymerization mechanism을 구현 하는데 적합 하다. stile polymerization mechanism은 Plasma 내부에서 polymer source를 분해 성장 시켜서 Polymer film 얻는 것이 아닌 source의 분자구조가 깨지지 않으면서 polymer growing 시키는 방법이다. dopamine source의 분자구조를 최대한 유지하려고 하는 이유는 metal absorption과 같은 특성이 dopamine chemical structure에 영향을 받기 때문이다. 많은 논문들에서 dopamine의 catechol group이 metal absorption, adhesion force에 영향을 주는 주요 인자라고 주장하고 있기 때문이다. 그래서 본 논문에서는 Dopamine source의 형태를 보존하면서 Polymerization 하는 방법으로 APP process를 사용 하여 낮은 전압에서 Polydopamine-like film을 제작 하였다. APP system 의 Plasma 방전부 에 Dopamine source를 유입하기 위하여 본 논문에서는 Piezo Spray 방식을 사용 하였다. Dopamine을 evaporator 하는 것이 어렵고 chemical composition이 유사한 monomer를 사용해서 Plasma Polymerization으로 Dopamine 분자 구조를 재현하는 것도 어렵다. 그래서 본 연구에서는 Dopamine을 water에 immerse 하고 Dopamine solution을 mist 상태로 만들어서 Plasma discharge area에 유입하였다. 이러한 방법으로 만들어진 film은 Polydopamine film은 아니지만 Polydopamine film과 유사한 Chemical composition, chemical structure, metal absorption을 갖는 것을 FT-IR, SEM, XPS을 이용 하여 확인 하였다. Dopamine source의 보존에 대하여 명확하게 확인하기 위하여 FT-IR을 측정 하였다. 전압에 따른 Benzene ring, hydroxyl group의 비율을 확인 하였다. 낮은 전압으로 coating 된 Polydopamine-like film 일수록 hydroxyl group peak($3400{\sim}3000cm^{-1}$)과 비교하여 Benzene ring peak($1600{\sim}1580cm^{-1}$ and $1510{\sim}500cm^{-1}$)이 흡수를 더 많이 하는 것을 확인 할 수 있다. 이것은 Benzene ring이 파괴되지 않고 보존되는 것을 보여준다. Dopamine에서 Benzene ring은 absorption main factor인 catechol에 있는 chemical structure이다. 즉 Benzene ring peak이 높을수록 Catechol이 잘 보존 되었다는 의미 이다. Catechol의 보존은 absorption main factor가 보존 된다는 의미 이다. 이러한 Polydopamine-like film으로 As, Cr, Mg, Cu 200ppm solution에 대한 filtration 능력을 확인 하였다. As, Cr, Cu, Mg 의 제거율이 각각 약25%, 35%, 45%, 65%인 것을 확인 하였다. 이 수치는 시중에 판매되는 제품들과 비교했을 때 300%~500% 향상된 수치 이다.

  • PDF

Fabrication of Label-Free Biochips Based on Localized Surface Plasmon Resonance (LSPR) and Its Application to Biosensors (국소 표면 플라즈몬 공명 (LSPR) 기반 비표지 바이오칩 제작 및 바이오센서로의 응용)

  • Kim, Do-Kyun;Park, Tae-Jung;Lee, Sang-Yup
    • KSBB Journal
    • /
    • v.24 no.1
    • /
    • pp.1-8
    • /
    • 2009
  • In the past decade, we have observed rapid advances in the development of biochips in many fields including medical and environmental monitoring. Biochip experiments involve immobilizing a ligand on a solid substrate surface, and monitoring its interaction with an analyte in a sample solution. Metal nanoparticles can display extinction bands on their surfaces. These charge density oscillations are simply known as the localized surface plasmon resonance (LSPR). The high sensitivity of LSPR has been utilized to design biochips for the label-free detection of biomolecular interactions with various ligands. LSPR-based optical biochips and biosensors are easy to fabricate, and the apparatus cost for the evaluation of optical characteristics is lower than that for the conventional surface plasmon resonance apparatus. Furthermore, the operation procedure has become more convenient as it does not require labeling procedure. In this paper, we review the recent advances in LSPR research and also describe the LSPR-based optical biosensor constructed with a core-shell dielectric nanoparticle biochip for its application to label-free biomolecular detections such as antigen-antibody interaction.

Synthesis and Characterization of Cu(In,Ga)Se2 Nanostructures by Top-down and Bottom-up Approach

  • Lee, Ji-Yeong;Seong, Won-Kyung;Moon, Myoung-Woon;Lee, Kwang-Ryeol;Yang, Cheol-Woong
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2012.08a
    • /
    • pp.440-440
    • /
    • 2012
  • Nanomaterials have emerged as new building blocks to construct light energy harvesting assemblies. Size dependent properties provide the basis for developing new and effective systems with semiconductor nanoparticles, quantized charging effects in metal nanoparticle or their combinations in 2 and 3 dimensions for expanding the possibility of developing new strategies for photovoltaic system. As top-down approach, we developed a simple and effective method for the large scale formation of self-assembled Cu(In,Ga)$Se_2$ (CIGS) nanostructures by ion beam irradiation. The compositional changes and morphological evolution were observed as a function of the irradiation time. As the ion irradiation time increased, the nano-dots were transformed into a nano-ridge structure due to the difference in the sputtering yields and diffusion rates of each element and the competition between sputtering and diffusion processes during irradiation. As bottom-up approach, we developed the growth of CIGS nanowires using thermal-chemical vapor deposition (CVD) method. Vapor-phase synthesis is probably the most extensively explored approach to the formation of 1D nanostructures such as whiskers, nanorods, and nanowires. However, unlike binary or ternary chalcogenides, the synthesis of quaternary CIGS nanostructures is challenging because of the difficulty in controlling the stoichiometry and phase structure. We introduced a method for synthesis of the single crystalline CIGS nanowires in the form of chalcopyrite using thermal-CVD without catalyst. It was confirmed that the CIGS nanowires are epitaxially grown on a sapphire substrate, having a length ranged from 3 to 100 micrometers and a diameter from 30 to 500 nm.

  • PDF

Nano Convergence Systems for Smart Living

  • Yeo, Jong-Souk
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2015.08a
    • /
    • pp.55-55
    • /
    • 2015
  • Today, engineers are facing new set of challenges that are quite different from the conventional ones. Information technologies are rapidly commoditizing while the paths beyond the current roadmaps became uncertain as various technologies have been pushed to their limits. Along with these changes in IT ecosystems, grand challenges such as global security, health, sustainability, and energy increasingly require trans-disciplinary solutions that go beyond the traditional arenas in STEM (Science, Technology, Engineering and Mathematics). Addressing these needs is shifting engineering education and research to a new paradigm where the emphasis is placed on the consilience for holistic and system level understanding and the convergence of technology with AHSD (arts, humanities, social science, and design). At the center of this evolutionary convergence, nanotechnologies are enabling novel functionalities such as bio-compatibility, flexibility, low power, and sustainability while on a mission to meet scalability and low cost for smart electronics, u-health, sensing networks, and self-sustainable energy systems. This talk introduces the efforts of convergence based on the emerging nano technology tool sets in the newly launched School of Integrated Technology and the Yonsei Institute of Convergence Technology at Yonsei International Campus. While the conventional devices have largely depended upon the inherent material properties, the newer devices are enabled by nanoscale dimensions and structures in increasingly standardized and scalable fabrication platform. Localized surface plasmon resonance in 0 dimensional nano particles and structures leads to subwavelength confinement and enhanced near-field interactions enabling novel field of metal photonics for sensing and integrated photonic applications [1,2]. Unique properties offered by 1 dimensional nanowires and 2 dimensional materials and structures can enable novel electronic, photonic, nano-bio, and biomimetic applications [3-5]. These novel functionalities offered by the emerging nanotechnologies are continuously finding pathways to be part of smart systems to improve the overall quality of life.

  • PDF

Review: Magnetite Synthesis using NanoFermentation (Review: NanoFermentation을 이용한 자철석 합성연구)

  • Moon, Ji-Won;Roh, Yul;Phelps, Tommy J.
    • Economic and Environmental Geology
    • /
    • v.45 no.2
    • /
    • pp.195-204
    • /
    • 2012
  • Biomineralization has been explored for geochemical cycles and microbial tolerance mechanisms to metal toxicity. Here, we are introducing NanoFermentation which enables economic, environmentally friendly, requiring low input energy, and scalable manufacturing of nano-dimensioned magnetite. We are also focusing on controlling factors of crystallite size which can determine superparamagnetism and ferrimagnetism. Controlling factors are such as microbial species, temperature, incubation time, medium composition, substituted elements and their concentration, precursor type, reaction volume, precursor concentration density and their combinations. Crystallite size distribution of biomagnetite depends on the balance between nuclei generation and crystal growth. Biomineralization will elucidate elemental cycles on earth crust and microbial ecology as well as it will be applied to material sciences and devices via massive production of nanomaterials.

Inorganic Printable Materials for Printed Electronics: TFT and Photovoltaic Application

  • Jeong, Seon-Ho;Lee, Byeong-Seok;Lee, Ji-Yun;Seo, Yeong-Hui;Kim, Ye-Na;More, Priyesh V.;Lee, Jae-Su;Jo, Ye-Jin;Choe, Yeong-Min;Ryu, Byeong-Hwan
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2011.05a
    • /
    • pp.1.1-1.1
    • /
    • 2011
  • Printed electronics based on the direct writing of solution processable functional materials have been of paramount interest and importance. In this talk, the synthesis of printable inorganic functional materials (conductors and semiconductors) for thin-film transistors (TFTs) and photovoltaic devices, device fabrication based on a printing technique, and specific characteristics of devices are presented. For printable conductor materials, Ag ink is designed to achieve the long-term dispersion stability and good adhesion property on a glass substrate, and Cu ink is sophisticatedly formulated to endow the oxidation stability in air and even aqueous solvent system. The both inks were successfully printed onto either polymer or glass substrate, exhibiting the superior conductivity comparable to that of bulk one. In addition, the organic thin-film transistor based on the printed metal source/drain electrode exhibits the electrical performance comparable to that of a transistor based on a vacuum deposited Au electrode. For printable amorphous oxide semiconductors (AOSs), I introduce the noble ways to resolve the critical problems, a high processing temperature above $400^{\circ}C$ and low mobility of AOSs annealed at a low temperature below $400^{\circ}C$. The dependency of TFT performances on the chemical structure of AOSs is compared and contrasted to clarify which factor should be considered to realize the low temperature annealed, high performance AOSs. For photovoltaic application, CI(G)S nanoparticle ink for solution processable high performance solar cells is presented. By overcoming the critical drawbacks of conventional solution processed CI(G)S absorber layers, the device quality dense CI(G)S layer is obtained, affording 7.3% efficiency CI(G)S photovoltaic device.

  • PDF

Alternative Sintering Technology of Printed Nanoparticles for Roll-to-Roll Process (롤투롤 인쇄공정 적용을 위한 차세대 나노입자 소결 기술)

  • Lee, Eun Kyung;Eun, Kyoungtae;Ahn, Young Seok;Kim, Yong Taek;Chon, Min-Woo;Choa, Sung-Hoon
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.21 no.4
    • /
    • pp.15-24
    • /
    • 2014
  • Recently, a variety of printing technologies, including ink jet, gravure, and roll-to-roll (R2R) printing, has generated intensive interest in the application of flexible and wearable electronic devices. However, the actual use of printing technique is much limited because the sintering process of the printed nanoparticle inks remains as a huge practical drawback. In the fabrication of the conductive metal film, a post-sintering process is required to achieve high conductivity of the printed film. The conventional thermal sintering takes considerable sintering times, and requires high temperatures. For application to flexible devices, the sintering temperature should be as low as possible to minimize the damage of polymer substrate. Several alternative sintering methods were suggested, such as laser, halogen lamp, infrared, plasma, ohmic, microwave, and etc. Eventually, the new sintering technique should be applicable to large area, R2R, and polymer substrate as well as low cost. This article reviews progress in recent technologies for several sintering methods. The advantages and disadvantages of each technology will be reviewed. Several issues for the application in R2R process are discussed.

Colorimetric Determination of pH Values using Silver Nanoparticles Conjugated with Cytochrome c

  • Park, Jun-Su;Choi, In-Hee;Kim, Young-Hun;Yi, Jong-Heop
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.9
    • /
    • pp.3433-3436
    • /
    • 2011
  • Some of metal nanoparticles have the potential for use as colorimetric assays for estimating solution properties, such as pH and temperature due to localized surface plasmon (LSP) phenomena. This report describes the use of silver nanoparticles (AgNP) conjugated with cytochrome c (Cyt c) for the colorimetric determination of solution pHs. When the pH of a solution decreases, the Cyt c immobilized on the AgNP undergoes a conformational change, leading to a decrease in the interparticle distance between Cyt c-AgNP probes and consequent red-shift in LSP. As a result, the color of the Cyt c-AgNP probe solution changes from yellow to red and finally to a grayish blue in the pH range from 11 to 3. This gradual color change can be used to determine the pH of a solution over a wide pH range, compared to other colorimetric methods that use gold nanoparticles.