• Title/Summary/Keyword: scanning electron microscope

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Electron Microscopy for the Morphological Characterization of Nanocellulose Materials (전자현미경을 이용한 나노셀룰로오스 물질의 형태학적 특성 분석 연구)

  • Kwon, Ohkyung;Shin, Soo-Jeong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.1
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    • pp.5-18
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    • 2016
  • Electron microscopy is an important investigation and analytical method for the morphological characterization of various cellulosic materials, such as micro-crystalline cellulose (MCC), microfibrillated cellulose (MFC), nanofibrillated cellulose (NFC), and cellulose nanocrystals (CNC). However, more accurate morphological analysis requires high-quality micrographs acquired from the proper use of an electron microscope and associated sample preparation methods. Understanding the interaction of electron and matter as well as the importance of sample preparation methods, including drying and staining methods, enables the production of high quality images with adequate information on the nanocellulosic materials. This paper provides a brief overview of the micro and nano structural analysis of cellulose, as investigated using transmission and scanning electron microscopy.

Controlled Release of Retinol Containing Microcapsules Prepared by Solvent Evaporation Method (액중건조법으로 제조한 Retinol 함유 마이크로캡슐의 방출 거동)

  • Kim, Se Ra;Shin, Young Jae;Lee, Chun Il;Pyo, Hyeong Bae;Shin, Jae Sup
    • Journal of Adhesion and Interface
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    • v.9 no.2
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    • pp.1-7
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    • 2008
  • Using biodegradable polycaprolactone, the microcapsules were prepared by solvent evaporation method. Retinol was selected as a core material, which was used as an important ingredient material in cosmetic fields. Poly(vinyl alcohol) was used as a stabilizer. The shape and property of the microcapsules were characterized by scanning electron microscope and differential scanning calorimeter, and the release rate of the microcapsule was measured by UV spectrophotometer. The microcapsules were prepared, changing the concentration of wall material, the stirring rate, and the concentration of stabilizer. Under the optimum condition, the microcapsules were formed, which showd 5~6 um in diameter and got the homogeneous sphere shape.

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Effect of Sc Addition on the Microstructure Modification of Al-6Si-2Cu Alloy (Sc 첨가에 따른 Al-6Si-2Cu 합금의 미세조직 개량화)

  • An, Seongbin;Kim, Chungseok
    • Journal of the Korean Society for Heat Treatment
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    • v.35 no.3
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    • pp.150-158
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    • 2022
  • The effects of scandium addition on the Al-6Si-2Cu Alloy were investigated. The Al-6Si-2Cu-Sc alloy was prepared by gravity die casting process. In this study, scandium was added at 0.2 wt%, 0.4 wt%, 0.8 wt%, and 1.0 wt%. The microstructure of Al-6Si-2Cu-Sc alloy was investigated using Optical Microscope, Field Emission Scanning Electron Microscope, Electron Back Scatter Diffraction, and Transmission Electron microscope. The microstructure of Al-6Si-2Cu alloy with scandium added changed from dendrite structure to equiaxed crystal structure in specimens of 0.4 wt% Sc or more, and coarse needle-shape eutectic Si and β-Al5FeSi phases were segmented and refined. The nanosized Al3Sc intermetallic compound was observed to be uniformly distributed in the modified Al matrix.

Fabrication of PLA/TiO2 nanofibers using melt-electro-spinning (용융전기방사를 이용한 PLA/TiO2 나노섬유의 개발)

  • Hwang, Ji-Young;Kim, Hui-Jin;Park, No-Hyung;Huh, Hoon;Park, Choon-Keun;Yoon, Jong-Won
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.21 no.3
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    • pp.124-128
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    • 2011
  • Electrospun webs have been widely investigated for applying to drug delivery system (DDS) because of their high specific surface area and high porosity. In this study, the composite webs of PLA (poly(lactic acid)) and $TiO_2$ were fabricated by melt-electro-spinning method for applying to drug delivery system. The morphologies of PLA/$TiO_2$, webs were observed using scanning electron microscope (SEM) and field emission transmission electron microscope (FE-TEM). The crystal structures of PLA/$TiO_2$ composite webs were confirmed by X-ray diffractometer (XRD).

Mechanical Properties of Elastomer TPVs due to Injection Molding Conditions (엘라스토머 TPV의 사출성형조건에 따른 기계적 물성)

  • Han, Seong-Ryeol;Jeong, Yeong-Deug
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.1
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    • pp.27-32
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    • 2006
  • Thermoplastic elastomer(TPE) has many advantages such as high flexibility, high elasticity and high elongation, etc. TPE is easily molded as plastic materials, therefore, many TPE parts are applied as home appliances and mechanical parts. However, its mechanical properties would be changed by injection molding conditions such as melt temperature, mold temperature, injection pressure and holding pressure, etc. In this study, the influences of the injection molding condition on the mechanical properties as tensile strength, hardness of thermoplastic vulcanizates(TPVs), which is one of the TPE, were investigated. By the injection molding experiment, the molding's tensile strength and hardness was influenced on the melt temperature and composition ratio of PP and EPDM. The morphology of moldings were shown by the scanning electron microscope.

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Fabrication and Linear & Nonlinear Optical Characterization of Photonic Crystals (포토닉 밴드갭 광결정의 제작과 선형 및 비선형 광학 특성 연구)

  • Ha Na Yeong;U Yeon Gyeong;Hwang Ji-Su;Jang Hye-Jeong;Park Byeong-Ju;U Jeong-Won
    • Proceedings of the Optical Society of Korea Conference
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    • 2002.07a
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    • pp.162-163
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    • 2002
  • 1-D photonic band-gap structure is identified in a cholesteric liquid crystal system. The optical transmission spectrum is measured and compared with the theoretical analysis. Nonlinear transmission is measured near the band edge. Also 3-D photonic band-gap structures are fabricated from dielectric colloidal polystyrene beads through a centrifuge method. The fabricated photonic crystals exhibit opalescent colors under white light and show a clear diffraction peak dependent on the incident angle of the light beam. Also the scanning electron microscope image was taken to verify the face-centered cubic crystal structure. Bragg's law and Snell's law are employed to describe the position of angle resolved diffraction peaks. It was shown that the optically deduced effective refractive index and lattice constants were in good agreement with the crystal structure identified by scanning electron microscope.

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Polymerization of Tetraethoxysilane by Using Remote Argon/dinitrogen oxide Microwave Plasma

  • Chun, Tae-Il;Rossbach, Volker
    • Textile Coloration and Finishing
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    • v.21 no.3
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    • pp.19-25
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    • 2009
  • Polymerization of tetraethoxysilane on a glass substrate was investigated by remote microwave plasma using argon with portions of nitrous oxide as carrier gas. Transparent layer like a thickness of 0.5 ${\mu}m$ 3 ${\mu}m$ were obtained, differing in chemical composition, depending on plasma power and treatment time as well as on ageing time. In general the milder the treatment and the shorter the ageing was, the higher was the content of organic structural elements in the layer. We have identified that the chemical structure of our samples composed of mainly Si O and Si C groups containing aliphatics, carbonyl groups. These results were obtained by X ray photon spectroscopy, Fourier transformed infrared spectroscopy, and scanning electron microscope combined with Energy dispersive X ray spectroscopy.