• Title/Summary/Keyword: film properties

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Properties and Structure of High Frequency Soft Magnetic Nano-composite Films

  • Ohnuma, Shigehiro;Masumoto, Hiroshi
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.403-407
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    • 2011
  • Metal-insulator type, nano-granular soft magnetic films have been reviewed from the viewpoint of high frequency magnetic materials. The formation of nano-granular structure is related to the magnitude of heat of formation of intergranule materials. Variation of the ratio of granule phase to intergranule phase in the film is found to produce various characteristics in the magnetic properties of the film. The HRTEM observation reveals that neighboring granules in the film with above 60 at.% Co, contact at considerable points and the films show soft magnetic properties which are explainable in terms of the random anisotropy model for nano-crystalline materials. Addition of Ni group elements in Co-O based films enhances their anisotropy field up to 400 Oe and they exhibit excellent frequency response of permeability. Also, large electromagnetic noise suppression effect is demonstrated as one of their potential applications.

Mechanical Properties of Polyethylene Films Containing Hydroxypropylated Potato Starch (하이드록시프로필화 감자 전분을 함유한 Polyethylene 필름의 기계적 특성)

  • 김미라;이선자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.2
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    • pp.423-428
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    • 1999
  • Potato starches were hydroxypropylated with 2.5, 5.0, 7.5, and 10.0% propylene oxide(PO) to improve mechanical properties of starch polyethylene film. Starch polyethylene cast films were prepared that contained 5% or 10% of the hydroxypropylated potato starch. Mechanical properties of these films were measured and compared to those of the films containing native potato starch. DS(degree of substitution) increased proportionally as propylene oxide concentration increased. Relative crystallinity in X ray diffraction patterns was decreased and starch granule observed by scanning electron micro scopy was destroyed by severe hydroxypropylation. In color properties of films, b value was not significantly different in the films but 5% starch polyethylene films with 2.5 PO starch showed the lowest L and a value. Tensile strength and strain energy of the films except the film containing 10.0 PO starch were higher than those of the containing native starch.

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Ferroelectirc Properties of Eu-doped PZT Thin Films (Eu 첨가에 따른 PZT 박막의 강유전 특성)

  • 김창일;손영훈;김경태;김동표;이병기
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.7
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    • pp.611-615
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    • 2003
  • Eu-doped lead zirconate titanate(Pb$\sub$1.1/(Zr$\sub$0.6/Ti$\sub$0.4/)O$_3$; PZT) thin films on the Pt/Ti/SiO$_2$/Si substrates prepared by a sol-gel method. The effect on structural and electrical properties of PZT thin films measured according to the Eu content. Eu-doping altered significantly dielectric and ferroelectric properties. The remanent polarization and the coercive field decreased with the increasing Eu content. The dielectric constant and the dielectric loss of PZT thin films decreased with the increasing Eu content. The 0.5 mol% of Eu-doped PZT thin film showed improved fatigue characteristic comparing to the undoped PZT thin film.

Preparation of Carrageenan-based Antimicrobial Films Incorporated With Sulfur Nanoparticles

  • Saedi, Shahab;Shokri, Mastaneh;Rhim, Jong-Whan
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.26 no.3
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    • pp.125-131
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    • 2020
  • Carrageenan-based functional films were prepared by adding two different types of sulfur nanoparticles (SNP) synthesized from sodium thiosulfate (SNPSTS) and elemental sulfur (SNPES). The films were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and thermal gravimetric analysis (TGA). Also, film properties such as UV-visible light transmittance, water contact angle (WCA), water vapor permeability (WVP), mechanical properties, and antibacterial activity were evaluated. SNPs were uniformly dispersed in the carrageenan matrix to form flexible films. The addition of SNP significantly increased the film properties such as water vapor barrier and surface hydrophobicity but did not affect the mechanical properties. The carrageenan/SNP composite film showed some antibacterial activity against foodborne pathogenic bacteria, L. monocytogenes and E. coli.

Properties Characterization of the Hydrophilic Inorganic Film as Function of Coating Thickness (코팅 두께에 따른 친수성 무기 필름의 특성 분석)

  • Joung, Yeunho;Choi, Won Seok;Shin, Yongtak;Lee, Minji;Kim, Heekon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.6
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    • pp.425-428
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    • 2013
  • In this paper, we present a novel hydrophilic coating material (Wellture Finetech, Korea) which can be utilized as a coating layer for anti-contamination for electrical and electronic system. The coating material was deposited on 4 inch silicon wafer with several different film thickness. The film thickness was controlled by spin coating speed. After curing of the film, we have scratched by permanent marker to check self-cleaning property of the film. Also we have executed several mechanical tests of the films. As the spin coating speed is increased, the film thickness was thinned from 230 nm to 125 nm. Contact angle of the film was lowered from $30^{\circ}$ to $12^{\circ}$ as the spin coating speed is increased from 700 to 2,500 rpm. On permanent marker scratched film surface coated at 1,000 rpm, we have poured regular city water to investigate self cleaning property of the film. The scratches were gradually separated from the film surface due to super-hydrophilicity of the film. Hardness of spin coated film was 9H measured by ASTM D3363 method. and adhesion of all film was 5B tested by ASTM D3359 method. Also, to get exact hardness value of the film, we have utilized a nano-indenter. As spin speed is increased, the hardness of film was increased from 3 GPa to 5 GPa.

Effect of Substrate Bias Voltage on the Electrical Properties of ZnO:Al Transparent Conducting Film Deposited on Organic Substrate (유기물 기판 위에 증착된 ZnO:Al 투명전도막의 전기적 특성에 미치는 기판 바이어스 전압의 효과)

  • Kwak, Dong-Joo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.1
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    • pp.78-84
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    • 2009
  • In this paper, ZnO:Al thin film was deposited on polyethylene terephthalate(PET) substrate by capacitively coupled r. f. magnetron sputtering method from a ZnO target mixed with 2wt[%] Al2O3 to investigate the possible application of ZnO:Al film as a transparent conducting electrode for film typed DSCs. The effect of substrate bias on the electrical properties and film structure were studied. The results showed that a positive bias applied to the substrate during sputtering contributed to an improvement of electrical properties of the film by attracting electrons in the plasma to bombard the growing films. These bombardments provided additional energy to the growing ZnO:Al film on the substrate, resulting in significant variations in film structure and electrical properties. Electrical resistivity of the film decreases significantly as the positive bias increases up to +30[V] However, as the positive bias increases over +30[V], the resistivity decreases. The transmittance varies little as the substrate bias is increased from 0 to +60[V], and as r. f. powers increases from 160[W] to 240[W]. The film with electrical resistivity as low as $1.8{\times}10^{-3}[{\Omega}-cm]$ and optical transmittance of about 87.8[%] were obtained for 1,012[nm] thick film deposited with a substrate bias of +30[V].

Preparation, structure, and properties of cellulose nanofibril/silk sericin composite film

  • Jang, Mi Jin;Park, Byung-Dae;Kweon, HaeYong;Jo, You-Young;Um, In Chul
    • International Journal of Industrial Entomology and Biomaterials
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    • v.31 no.1
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    • pp.1-6
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    • 2015
  • Recently, sericin has attracted increasing attention in biomedical and cosmetic research because of its useful properties including acceleration of wound healing, improvement of cell attachment, and inhibition of ultraviolet-B induced apoptosis. However, sericin films have poor mechanical properties, which restricts the application to those fields. In this study, cellulose nanofibril (CNF)/sericin composite films were fabricated by solvent casting, and the effects of ultrasonication time and CNF content on the solution turbidity, molecular conformation, and film mechanical properties of sericin film were examined. As the ultrasonication time increased, the turbidity of the CNF/sericin suspension decreased. Conversely, as the CNF content increased, the turbidity increased. However, ${\beta}$-sheet crystallization and mechanical properties remained almost unchanged by varying the ultrasonication time and CNF content, indicating that CNF is not effective to improve the mechanical properties of sericin films.

Heat-Treated Polyvinyl Alcohol/Cellulose Nanocrystal Film with Improved Mechanical Properties and Water Resistance (내수성 및 기계적 물성이 향상된 열처리된 폴리비닐알코올/셀룰로오스 나노결정 필름)

  • Nguyen, Son Van;Lee, Bong-Kee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.11
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    • pp.1-8
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    • 2021
  • In this study, the water resistance and mechanical properties of heat-treated polyvinyl alcohol (PVA)/cellulose nanocrystal (CNC) films were investigated. PVA is the most commonly used synthetic biodegradable polymers owing to its excellent properties. However, the water/moisture sensitivity and relatively poor mechanical properties of PVA limits its applications. Although heat treatment is a conventionally used method to improve the mechanical strength and water resistance of PVA, the effectiveness of this method is insufficient. Therefore, CNC was used to further improve the mechanical properties and water resistance of the heat-treated PVA film. PVA/CNC nanocomposites containing CNC contents of 0, 1, 3, 5, and 10 wt% were fabricated using solvent casting and subsequent heat treatment. The mechanical properties and water resistance of PVA/CNC films were significantly improved. The tensile strength and wet strength of the PVA/CNC film with a CNC content of 5 wt% (PVA/CNC 5%) were 184.5% and 136.0% higher than those of the untreated PVA, respectively. In addition, the water absorption and solubility of PVA/CNC 5% were 56.6% and 68.2% lower than those of the untreated PVA.

CharacteristicProperties of Low-k Thin Film Deposited by Sputtering (스퍼터링에 의한 Low-k 박막의 특성)

  • Oh, Teresa
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.7
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    • pp.3160-3164
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    • 2012
  • To obtain available process at low temperature, SiOC thin film was prepared with various flow rates by using the rf magnetron sputtering, and AZO thin film was also deposited on SiOC film by rf magnetron sputtering system. The optical electrical properties of the SiOC film and SiOC/AZO were analyzed by the uv visible spectrometer and PL spectra. SiOC film on n type Si showed various type emission according to the deposition condition. The SiOC film showed the blue shift with increasing the thickness in PL spectra. AZO/SiOC/Si film had a broad emission characteristic, which is enhanced the efficiency in solar cell.

Structural and Dielectric Properties of PZT(20/80)/PZT(80/20) Heterolayered Thin Films Prepared by Sol-Gel Method (Sol-Gel법으로 제작한 PZT(20/80)/PZT(80/20) 이종층 박막의 구조 및 유전 특성)

  • 심광택;이영희
    • Electrical & Electronic Materials
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    • v.10 no.10
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    • pp.983-988
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    • 1997
  • We investigated the structural and dielectric properties of PZT(20/80)/PZT(80/20) heterolayered thin films that fabricated by the alkoxide-based Sol-Gel method. PZT(20/80)/PZT(80/20) heterolayered thin films were spin-coated on the Pt/Ti/SiO$_2$/Si substrate with PZT(20/80) film of tetragonal structure and PZT(80/20) film of rhombohedral structure by turns. Each layers were dried to remove the organic materials at 30$0^{\circ}C$ for 30min and sintered at $650^{\circ}C$ for 1hr. This procedure was repeated several times to form PZT(20/80)/PZT(80/20) heterolayered films and thickness of the film obtained by one-times of drying/sintering process was approximately 80-90nm. PZt-1, 3, 5 films with top layer of PZT(20/80) film of tetragonal structure showed fine grain structure and PZT-2, 4, 6 films with top layer of PZT(80/20) film of rhombohedral structure showed the dense grain microstructure without rosette-type. Dielectric constant and dielectric loss of the PZT-6 film were approximaterly 1385 and 3.3% respectively. Increasing the number of coatings remanent polarization was increased and coercive field was decreased and the values of the PZT-6 film were 8.13$\mu$C/cm$^2$and 12.5kV/cm respectively.

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