• 센서학회지
• /
• 제22권6호
• /
• pp.400-403
• /
• 2013

The piezoelectric composite film of ferroelectric PZT ceramic ($PbZr_xTi_{1-x}O_3$) and polymer (PDMS, Polydimethylsiloxane) was prepared to improve the flexibility of piezoelectric material. The bar coating method was applied to fabricate flexible nanocomposite film with large surface area by low cost process. In the case of using metal electrode on the composite film, although there is no problem by bending process, the electrode is usually broken away from the film by stretching process. However, the well-attached, flexible CNT electrode on PZT/PDMS film improved flexibility, especially stretchability. PZT particles was usually settled down into polymer matrix due to gravity of the weighty particle, so to improve the dispersion of PZT powder in polymer matrix, small amount of additives (CNT powder, Carbon nanotube powder) was physically mixed with the matrix. By stretching the film, an output voltage of PZT(70 wt%)/PDMS with CNT (0.5 wt%) was measured.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
• /
• pp.182-183
• /
• 2008

본 연구에서는 유전 손실이 낮고, 고분자(LCP)의 유전율을 높이기 위하여 (100-x)LCP(polymer)-xNPO(ceramic) 복합체 (x= 0, 10, 20, 30, 40, 50)의 유전 특성 및 미세구조를 연구하였다. LCP와 ceramic filler(NPO)는 Brabender Mixer를 사용하여 $300^{\circ}C$에서 혼합한 후, Hot press 사용하여 $300^{\circ}C$, 7ton 성형 압력으로 pellet 형태 $(2.5cm\times2.5cm\times0.1cm)$로 제조 하였다. LCP-NPO 복합 소재를 SEM을 통해 미세구조를 관찰하였고, 복합체의 유전 특성을 조사하였다.

• 세라미스트
• /
• 제22권2호
• /
• pp.110-121
• /
• 2019

Triboelectric nanogenerators and piezoelectric nanogenerators are a spotlighted energy harvesting method that converts the wasted mechanical energy from the environment into usable electrical energy. In the case of triboelectric nanogenerators, researches have been mainly focused on high permittivity and flexible polymer materials, and in the case of piezoelectric nanogenerators, researches have been focused on ceramic materials exhibiting high polarization characteristics. Recently, many researches have been conducted to improve durability and power in various environments by using composite materials which have flexible properties of polymer, high permittivity, thermal resistance and high polarization properties of ceramics. This article reviews the energy harvesting studies reported about composites materials using ceramics and polymers.

• 마이크로전자및패키징학회지
• /
• 제11권1호
• /
• pp.87-96
• /
• 2004

폴리머/세라믹 복합체는 유기기판용 내장형 커패시터의 가장 유망한 재료다. 폴리머/세라믹 복합체의 유효유전상수를 예측하는 것은 복합재료의 설계에 있어 매우 중요하다. 본 논문에서는 크기가 다른 5가지 $BaTiO_3$ 분말을 이용하여 분말함량에 따른 에폭시/$BaTiO_3$ 복합 내장형 커패시터 필름의 유전상수를 측정하였다. 그 측정 결과를 여러 가지 이론식들에 최소 자승법을 이용해 fitting하여 폴리머/세라믹 복합체의 유효유전상수를 예측하는데 가장 유용한 식을 찾고 BaTiO$_3$ 분말의 유전상수를 추정하고자 하였다. Lichtenecker식과 Jayasundere-Smith식이 에폭시/$BaTiO_3$ 복합 내장형 커패시터 필름의 유전상수 예측에 유용한 것으로 나타났다. 피팅을 통해 계산된 $BaTiO_3$ 분말의 유전상수는 분말의 크기에 따라 100 에서 600 사이였는데 이는 다결정 세라믹 $BaTiO_3$의 유전상수보다 작은 값이다.

• 한국전기전자재료학회논문지
• /
• 제22권11호
• /
• pp.935-940
• /
• 2009

In this research, the composites (100-x)LCP-xBNT (x = 0, 10, 20, 30, 40 vol.%) were fabricated with thermoplastic LCP(Liquid Crystal Polymer) and BNT($BaNd_2Ti_4O_{12}$) which is a high frequency dielectric material. Their dielectric properties, mechanical strength and microstructure were investigated by Impedance analyser, Instron and SEM. In order to fabricate LCP-BNT composites, LCP resin was put into the twin screw type mixer($310^{\circ}C$), melted by keeping for 10 min. After that, BNT filler was dispersed with melted LCP resin for 15 min. in the mixer. For measuring the dielectric properties and mechanical strength, Composite specimens were made by pressing composite granule (LCP-BNT) with 7 ton in the mold at $310^{\circ}C$. With increasing the BNT content (0~40 vol.%) of the composite, Its dielectric constant increased, dielectric loss and flexural strength decreased. The dielectric constant and flexural strength of composites with 20~30 vol.% of BNT filler are 4.1~6.0 and 35~55 MPa respectively. BNT/LCP composite is the potential substrate material for the high frequency application.

• 한국세라믹학회지
• /
• 제54권6호
• /
• pp.499-505
• /
• 2017

Flexible silicon carbide fibrous mats were fabricated by a combination of electrospinning and a polymer-derived ceramics route. Polycarbosilane was used as a solute with various solvent mixtures, such as toluene and dimethylformamide. The electrospun PCS fibrous mats were cured under a halogen vapor atmosphere and heat treated at $1300^{\circ}C$. The structure, fiber morphology, thermal behavior, and crystallization of the fabricated SiC fibrous mats were analyzed via scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermal imaging. The prepared SiC fibrous mats were composed of randomly distributed fibers approximately $3{\mu}m$ in diameter. The heat radiation of the SiC fiber mats reached $1600^{\circ}C$ under microwave radiation at a frequency of 2.45 GHz.

• Elastomers and Composites
• /
• 제34권5호
• /
• pp.407-413
• /
• 1999

비세라믹 복합절연소재는 기계적 물성, 환경문제, 대량생산과 용이한 설계등의 우수한 특성으로 인해 전력산업분야에서 관심의 대상이 되어왔다. 또한 세라믹 절연체에 비하여 가볍고, 더욱 강인한 물성을 가진다는 장점이 있다. 본 연구에서는 뛰어난 전기 절연 특성과 우수한 내열, 내산화, 내오존성과 내후성을 가진 ethylene propylene diene monomer(EPDM)를 절연소재로 사용하였다. 특히, EPDM은 다른 고무 복합체에 비해 우수한 소수성을 가지기 때문에 장기간 사용이 가능하다는 점에서 본 연구에서는 EPDM 복합체의 유변학적 물성, 전기적물성, 그리고 접촉각의 측정을 통한 소수성 및 회복력에 관한 연구를 하였다. 또한 SEM을 사용하여 표면 형태학적 연구를 수행하였다.

• 한국분말재료학회지
• /
• 제10권5호
• /
• pp.310-317
• /
• 2003

Two-component ceramic (alumina-zirconia) composites were fabricated by a soft-solution process in which polyethylene glycol (PEG) was used as a polymeric carrier. Metal salts and PEG were dissolved in ethyl alcohol without any precipitation in 1:1 volume ratio of alumina and zirconia. In the non-aqueous system, the flammable solvent made explosive, exothermic reaction during drying process. The reaction resulted in formation of volume expanded, porous precursor powders by a vigorous decomposition of organic components in the precursor sol. The PEG content affected the grain size of sintered composites as well as the morphology of precursor powders. The difference of microstructure in sintered composite was attribute to the solubility and homogeneity of metal cations in precursor sol. At the optimum amount of the PEG polymer, the metal ions were dispersed effectively in solution and a homogeneous polymeric network was formed. It made less agglomerated particles in the precursor sol and affected on uniform grain size in sintered composite.

• 한국세라믹학회지
• /
• 제27권1호
• /
• pp.35-42
• /
• 1990

In the present investigation, ceramic PZT and Polymer were prepared. The former is Pb[(Sn1/2Sb1/2)0.1 Ti0.27Zr0.63]O3 including Pb(Sn1/2Sb1/2)O3 with good pyroelectric effect, and the latter PVA(Poly Vinyl Alcohol) with good plasticity. Then, they were fabricated to be flat by using 0-3 connectivity which is rather easily fabricated and capable of making thin film, extending surface area among the connectivities. Such were applied to the sample as variation of intensity of poling field, poling temperature, volume fraction between ceramic and polymer. Then dielectric constant, pyroelectric current, pyroelectric coefficient and the figure of merit were measured. And then their effects on pyroelectric characteristics were observed.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.1200-1203
• /
• 2004

We investigated the molecular aligning capability of a polymer layer containing ceramic nanoparticles which can be used as a gate insulator of organic thin-film transistors (OTFTs). Because of the enhanced dielectric properties arising from the nanoparticles and molecular aligning properties of the polymer, the composite layer provides excellent mobility characteristics of the OTFTs.