• Title, Summary, Keyword: Ceramic-polymer composite

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고충전 polymer/ceramic composite에서 유전 특성의 mixing rule

  • Lee, Ji-Ae;Sin, Hyo-Sun;Hong, Yeon-U;Yeo, Dong-Hun;Kim, Jong-Hui;Yun, Ho-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.309-309
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    • 2008
  • 전자 산업의 발달로 인해 전자기기에 소형화, 경량화 및 다기능화가 요구되면서 고밀도화, 고집적화가 필요하게 되었다. 이와 같은 부품의 고집적화 기술로 최근 제시되고 있는 방법 중 하나는 ceramic powder로 구성된 유전층에 polymer를 infiltration시키고 cure 과정을 거쳐 소결공정 없이 유전층을 완성하는 것이다. 그리고 이 유전층을 layer 단위로 build up하는 방법을 이용하여 반복적으로 형성하는 기술이 연구되고 있다. 그러나 고충전된 polymer/ceramic composite에서 유전 특성은 기존에 알려진 저충전 구조에서의 mixing 이론을 따를 것인지에 대한 실증적인 연구는 이루어지지 않았다. 본 연구에서는 ceramic powder $Al_2O_3$를 이용하여 polymer의 함량을 최소화하여 paste 를 제조하고, 스크린 프린팅 방법으로 인쇄하여 ceramic layer를 제작하였다. 그리고 이 위에 polymer infiltration 과정을 동하여 고충전 ceramic/polymer composite layer를 제작하였다. 또한, $Al_2O_3$를 filter로 사용한 저충전 polymer/ceramic composite에서의 mixing rule과 비교하여 복합체의 유전 특성을 설명하였다.

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Effects of Interface Porosity on Dielectric and Piezoelectric Properties of BaTiO3-Polymer Composites of O-3 Type Connectivity (O-3형 BaTiO3-폴리머 복합체의 계면기공율 변화에 따른 유전 및 압전특성)

  • 이형규;김호기
    • Journal of the Korean Ceramic Society
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    • v.26 no.5
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    • pp.617-624
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    • 1989
  • Piezoelectric composites of O-3 connectivity were prepared by thermosetting barium titanate-phenolic resin composite under various cruing pressure. Among three kinds of pore in O-3 type ceramic-polymer composite, such as matrix pores, particle pores, and ceramic-polymer interface pores, the effect of interface porosity on the dielectric and piezoelectric constant was investigated. In pure barium titanate ceramics, the porosity factor of dielectric and piezoelectric constants were 5.7 and 5.0, respectively. However, in BaTiO3-polymer composite, the interface porosity factor of the piezoelectric constant was greater than that of the dielectric constant, interface porosity factor b in d33 was 9.8 and in r 4.6. On the other, piezoelectric voltage constant g33 was independent of the porosity of barium titanate ceramics. But in composite system, the piezoelectric voltage constant g33 was decreased with interface porosity.

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Dielectric and Mechanical Properties of BNT-LCP Composites

  • Park, Myoung-Sung;Cho, Jeong-Ho;Kim, Byung-Ik;Chun, Myoung-Pyo;Nahm, Sahn
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.7
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    • pp.547-553
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    • 2011
  • We investigated the dielectric and mechanical properties of ceramic polymer composite xBNT - (1-x)LCP (x= 0, 10, 20, 30, 40 vol.%). The disk shaped BNT ($BaNd_2Ti_4O_{12}$) - LCP (liquid crystal polymer) composite samples were prepared by compression molding method. With increasing the BNT content in composites from 10 to 40 vol.%, the dielectric constant increased but the dielectric loss as well as bending strength of composites reduced. These composites were well described with modified Lichtenecker's model having k = 0.392 and 0.303 for the first and second ball milled BNT filled composites, which means that the BNT filler in composites are well dispersed. The dielectric constant of the composite comprised of the second milled BNT ($D_{50}$ = 1.39 um) was higher that of the composite of the first milled BNT ($D_{50}$= 2.45 um), which seems to be related with the different particle size and dispersion of BNT fillers in LCP matrix. The bending strength of the composite containing the second milled BNT was superior to that of the composite of the first milled BNT.

Electrical Properties of PVdF/PVP Composite Filled with Carbon Nanotubes Prepared by Floating Catalyst Method

  • Kim, Woon-Soo;Song, Hee-Suk;Lee, Bang-One;Kwon, Kyung-Hee;Lim, Yun-Soo;Kim, Myung-Soo
    • Macromolecular Research
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    • v.10 no.5
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    • pp.253-258
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    • 2002
  • The multi-wall carbon nanotubes (MWNTs) with graphite crystal structure were synthesized by the catalytic decomposition of a ferrocene-xylene mixture in a quartz tube reactor to use as the conductive filler in the binary polymer matrix composed of poly(vinylidene fluoride) (PVdF) and poly(vinyl pyrrolidone) (PVP) for the EMI (electromagnetic interference) shielding applications. The yield of MWNTS was significantly dependent on the reaction temperature and the mole ratio of ferrocene to xylene, approaching to the maximum at 800 $^{\circ}C$ and 0.065 mole ratio. The electrical conductivity of the MWNTs-filled PVdF/PVP composite proportionally depended on the mass ratio of MWNTs to the binary polymer matrix, enhancing significantly from 0.56 to 26.7 S/cm with the raise of the mass ratio of MWNTs from 0.1 to 0.4. Based on the higher electrical conductivity and better EMI shielding effectiveness than the carbon nanofibers (CNFs)-filled coating materials, the MWNTs-filled binary polymer matrix showed a prospective possibility to apply to the EMI shielding materials. Moreover, the good adhesive strength confirmed that the binary polymer matrix could be used for improving the plastic properties of the EMI shielding materials.

Electrical Conductivity of Carbon Fiber-Polymer Composite (Carbon 화이버-폴리머 복합체의 전기적 특성)

  • 이재연;최경만
    • Journal of the Korean Ceramic Society
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    • v.35 no.6
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    • pp.603-609
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    • 1998
  • The composites of insulating polymer filled with conducting carbon-fiber were fabricated by molding press method. To understand the fiber aspect-ratio dependence of electrical conductivity the aspect ratio was varied from 4 to 10 The percolation thresholds of transition from the insulator to the conductor de-creased as the fiber aspect ratio increased. The percolation threshold of fiber-segregated composite in this study was smaller than that of fiber-random composite shown in other study. When the electrical con-ductivity curves were fitted by general effective medium equation morphological variable(t) decreased as the fiber aspect-ratio increased.

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$MoSi_2$/SiC Ceramic Composites Prepared by Polymer Pyrolysis (고분자 열분해에 의한 $MoSi_2$/SiC 세라믹 복합체)

  • 김범섭;김득중;김동표
    • Journal of the Korean Ceramic Society
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    • v.37 no.8
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    • pp.805-810
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    • 2000
  • The formation, microstructure and properties of MoSi2/SiC ceramic composites by polymer pyrolysis were investigated for the application of heating element material. Polymethylsiloxanes were mixed with Si, SiC, MoSi2 as filler and ceramic composites prepared by pyrolysis in N2 atmosphere at 1320~145$0^{\circ}C$ were studied. Dimensional change, density variation and phases were analyzed and correlated to the resulting material properties. Microstructures of ceramic composite prepared by polymer pyrolysis were composed of MoSi2, SiC and silicon oxycarbide glass matrix. Depending on the pyrolysis conditions, ceramic composites with a density of 86~90 TD%, a fracture strength of 213~284 MPa, a thermal expansion coefficient of 4~7$\times$10-6 were obtained. The electrical resistivity of the specimen decreased with increasing of temperature up to 50$0^{\circ}C$.

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Dielectric and Piezoelectric of Ceramic-Polymer Composite with Ceramic Particle Size (세라믹 분말 크기가 압전 세라믹-폴리머 복합체의 유전 및 압전 특성에 미치는 영향)

  • 이형규;김호기
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.63-65
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    • 1989
  • Piezoelectric BaTiO$_3$-polymer composite were investigated for dielectric and piezoelectric properties with the barium titanate active particle size. Under the condition of the same density and ceramic volume ratio of composite, the dielectric and piezoelectric constant of composite are increasing as the ceramic particle size in composite are increasing. The surface layer model was quoted to explain these phenomena in our system and experimentally confirmed. The connectivity parameter of modified cube model of composite was calculated from the dielectric constant variation as their particle size. The connectivity parameter X and Y were 77.8% and 98.9% respectively. It means that the barium titanate particle distribution in composite nearly approach to the parallel mode. It was experimentally confirmed that the surface layer has low dielectric and nonferroelectric properties. Dielectric constant and thickness of surface layer were calculated from the equivalent circuit of composite.

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Preparation of Organic/Inorganic Siloxane Composite Membranes and Concentration of n-butanol from ABE Solution by Pervaporation (Siloxane 유-무기 복합막 제조와 투과증발법을 이용한 Acetone-Butanol-Ethanol (ABE) 용액에서 부탄올의 분리)

  • Jee, Ki Yong;Lee, Yong Taek
    • Korean Chemical Engineering Research
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    • v.51 no.5
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    • pp.580-586
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    • 2013
  • In this paper, polymer composite membranes and ceramic composite membranes were prepared in order to compare differences in pervaporation performances relative to the support layers. PVDF was used for the polymer support layers, and $a-Al_2O_3$ was used for the ceramic support layers. For active layer was coated for PDMS, which is a rubbery polymer. The characterization of membranes were analysed by SEM, contact angle, and XPS. We studied performances relative to the composite membrane support layers in the ABE mixture solutions. The results of the pervaporation, the flux of the ceramic composite membrane was shown to be $250.87g/m^2h$, which was higher than that of polymer composite membranes, at $195.64g/m^2h$. However, it was determined that the separation factor of the polymer composite membranes was 31.98 which were higher than that of the ceramic composite membranes, at 20.66.

3-D Underwater Object Restoration Using Ultrasonic Transducer Fabricated with 1-3 Type Piezoceramic/Polymer Composite and Neural Networks (1-3형 복합압전체로 제작한 초음파 트랜스듀서와 신경회로망을 이용한 3차원 수중 물체복원)

  • Jo, Hyeon-Cheol;Lee, Gi-Seong;Choe, Heon-Il;Sa, Gong-Geon
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.6
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    • pp.456-461
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    • 1999
  • In this study, the characteristics of Ultrasonic Transducer fabricated with PZT-Polymer 1-3 type piezoelectric ceramic/polymer composite are investigated. 3-D underwater object restoration using the self-made ultrasonic transducer and modified SCL(Simple Competitive Learning) neural network was presented. The ultrasonic transducer was satisfied with the required condition of commerical ultrasonic transducer in underwater. The modified SCL neural network using the acquired object data $16\times16$ low resolution image was used for object restoration of $32\times32$ high resolution image. The experimental results have shown that the ultrasonic transducer fabricated with PZT-Polymer 1-3 type piezoelectric ceramic/polymer composite could be applied for SONAR system.

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