• 한국전기전자재료학회논문지
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• 제25권3호
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• pp.224-228
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• 2012

We have developed new materials that lead to methyl meth acrylate monomer and styrene monomer to using polymerization method. The materials have a powder form and show liquid behavior. We call the "Electronic Bead". An our experiment, a positive-charged particle has $TiO_2$, polymer and CCA(-), while a negative-charged particle consists of carbon black, polymer and CCA(+). The charged particles have electrical characteristic of white -10 uC/g and black 10 uC/g, respectively. Also, these particles have good fluidity by additive of nano-sized silica. Using these materials, we demonstrated prototype displays that have $320{\times}320$ array of pixels and 6-in-diagonal viewable image size, driven by passive-matrix addressing. The reflectivity shows about 30% even though our experiment is at the beginning point. Also, the panel has contrast ratio 6:1. We think there are many chances to improve reflectivity through modifying components of particle resin, mixture ratio of each particle, panel structure and so on.

• 한국주조공학회지
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• 제13권5호
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• pp.450-461
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• 1993

AC4C alloy casts in the metallic mold, zircon sand mold, silica sand mold and shell mold with the pouring temperatures of 680, 710 and $740^{\circ}C$ have been investigated. The tensile strength, elongation and hardness of AC4C alloy castings have been influenced by the kind of molds used. The mechanical properties in zircon sand mold castings were greater than those in other sand mold castings, but were inferior to the properties in metallic mold castings. Eutectic Si particle size and DAS were increased in the order of metallic mold, ziron sand mold, silica sand mold and shell mold. Also, they were increased with the increase of pouring temperatures. DAS, eutectic Si particle size and grain size decreased with the increase of mechanical properties as the cooling rate increased. The eutectic Si particle size and DAS of AC4C alloy castings after T6 treatment were decreased in as-cast. The variation of eutectic Si particle size has been effected on the tensile strength, elongation and fractured surface.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.571-572
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• 2006

Tungsten CMP needs interconnect of semiconductor device ULSI chip and metal plug formation, CMP technology is essential indispensable method for local planarization. This Slurry development also for tungsten CMP is important, slurry of metal wiring material that is used present is depending real condition abroad. It is target that this research makes slurry of efficiency that overmatch slurry that is such than existing because focus and use colloidal silica by abrasive particle to internal production technology development. Compared selectivity of slurry that is developed with competitor slurry using 8" tungsten wafer and 8" oxide wafer in this experiment. And removal rate measures about density change of $H_2O_2$ and Fe particle. Also, corrosion potential and current density measure about Fe ion and Fe particle. As a result, selectivity find 83:1, and expressed similar removal rate and corrosion potential and current density value comparing with competitor slurry.

• 공업화학
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• 제26권5호
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• pp.549-556
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• 2015

한약재에서 추출한 해충기피용액과 실리카를 혼합하여 해충기피 실리카 졸을 제조하고, 분무건조법을 이용하여 마이크로 단위의 해충기피용액이 포함된 다공성 구형 분말을 제조하였다. 분무건조법을 통해 제조된 해충기피 분말의 특성분석을 위해 해충기피 졸의 농도(해충기피용액, 실리카) 및 분무 건조 장비의 조건에 따라 분말 모폴로지, 입자크기별 입경분포, 열적 안정성 분석을 실시하였다. 해충기피 졸의 농도가 4, 7 wt% 및 10 wt%일 때 각각 평균 입자 크기가 8.3, $9.5{\mu}m$ 및 $11.7{\mu}m$ 순으로 농도가 증가할수록 분말의 직경이 커졌다. 반면에 빠른 가스 주입속도 상태에서 노즐입구온도 및 용액주입속도 증가에 의한 분말 입경의 증가는 미미하였다. 또한, 열중량 분석법을 통하여, 구형의 다공성 분말 안에 해충기피 용액이 담지 되어있고, 이들은 $200^{\circ}C$까지 열적 안정성이 확보됨을 확인하였다. 분무건조를 통한 해충기피 분말은 평균 $9{\sim}10{\mu}m$이고, 열적 안정성을 가지므로 컴파운딩 및 필름제조공정에 응용이 가능할 것으로 기대된다.

• Tribology and Lubricants
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• 제25권4호
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• pp.261-264
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• 2009

Environmental factors affect parts of the automobile. When dust particles are embedded, specially, friction and wear of the rubber-seal in automobile chassis system are increased. Increase in friction and wear leads to weakness of component and reduction of mechanical life. In this study, the wear characteristics of rubber-seal for inflow of dust particles are investigated. Silica($SiO_2$) and alumina($Al_2O_3$) particles are used as a dust particle because these particles are main elements of dust particles. The sliding wear tester are used for investigate the wear characteristics of rubber-seal. If the single dust particle($SiO_2$) is embedded in the rubber-seal component, the influence of dust particle size is more than that of inflow rate on the wear characteristics of rubber-seal. If the mixed dust particles are embedded in the rubber-seal component, the wear rate is increased as the rate of alumina that has a bigger hardness is increased. If the mixed dust particles that have different hardness are embedded in the rubber-seal component, the influence of particle size is more than that of particle hardness.

• 공업화학
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• 제16권5호
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• pp.672-676
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• 2005

치아수복용 고분자 복합체(polymeric dental restorative composite, PDRC)의 전치부와 구치부에의 응용 가능성을 높이고자 PDRC를 구성하는 실리카 충진재를 다양한 온도에서 열처리시켜 siloxane 기로 연결된 구조의 개질된 실리카를 제조하고 이를 PDRC 제조에 사용하였다. 제조된 PDRC의 중합 특성을 중합전환률, 중합깊이, 그리고 체적 중합수축률 등을 분석하여 고찰하였다. 실험 결과, 사용된 실리카의 열처리 온도가 높아짐에 따라 제조된 PDRC의 중합깊이는 감소하였고 체적 중합수축률과 중합전환률 값은 실리카 입자의 평균크기 감소에 따른 PDRC 내 resin matrix의 상대적 양의 증가로 인해 일정하게 증가함을 알 수 있었다.

• 한국세라믹학회지
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• 제42권6호
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• pp.399-404
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• 2005

Anti-reflection film was coated by using spherical silica nano colloidal particles and fumed silica particles. Silica colloid sol was reserved between two inclined slide glasses by capillary force, and particles were stacked to form a film onto the substrate as the upper glass was sliding. The deposition processes were studied to enhance the wavelength dependency of the light transmittance and to control the effective refractive index of the film. Both of the spherical and fumed silica particles showed an enhancement of $4.0-4.4\%$ in light transmittance by one step coating. The dependence of the transmittance on wavelength was largely improved at the longer wavelength by partial coating of fumed particles on the film of spherical particles. The effective refractive index of the film was controlled by removing latex particles that were co-deposited with silica particles. Using this process the light reflectance from one side of the glass substrate could be reduced from $4.2\%$ to $0.6\%$ although zero reflectance was not achieved due to the agglomeration of the latex particles.

• 한국분말재료학회지
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• 제21권1호
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• pp.21-27
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• 2014

In this study, diatomite based materials were investigated as a support filter for silica particle coating. The silica sol for coating was synthesized by a st$\ddot{o}$ber process. The diatomite support was dry-pressed at 10 MPa and sintered at $1200^{\circ}C$ for 1 hour. The coating sol was prepared as a mixture of EtOH and silica sol. The diatomite support was coated by a dip-coating process. Silica coated diatomite filter was sintered at $1000{\sim}1200^{\circ}C$ for 1 hour. The largest pore size was decreased with increasing concentration ratio of coating sol. The gas and water permeability of silica coated diatomite decreased with increasing of concentration ratio of the coating sol.

• 콘크리트학회논문집
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• 제25권3호
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• pp.305-312
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• 2013

이 연구는 물-결합재(W/B) 비에 따른 실리카 퓸이 알칼리 활성화 슬래그 시멘트(AASC)에 미치는 유동성과 강도 특성에 대한 연구이다. W/B비는 0.50에서 0.60까지 0.05 단위로 일정하게 변화시켰다. 실리카 퓸은 고로슬래그 중량의 0%에서 50%까지 치환시켰다. 활성화제는 수산화나트륨(NaOH)를 사용하였고, 농도는 3M로 하였다. W/B 비에 따른 강도는 1, 3, 7 그리고 28일을 측정하였다. 유동성 측정 결과는 실리카 퓸의 치환율이 증가할수록 감소하였다. 압축강도는 실리카 퓸의 치환율이 증가할수록 증가하였다. 또한 W/B 비가 증가할수록 모든 재령에서 강도는 감소하였다. 실리카 퓸은 W/B 비와 실리카 퓸의 치환율에 따라서 활성화 반응을 증대시켜 강도를 증가시키는 것을 알 수 있었다.

• 방사성폐기물학회지
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• 제9권1호
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• pp.1-11
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• 2011

에멀션 기반의 계면활성제를 이용한 주형합성법을 이용하여 산촉매로서 염산과 실리카의 전구체인 테트라에톡시실란을 사용함으로써 메조다공성 실리카 마이크로스피어를 합성하였다. 테트라에톡시실란의 농도 증가에 의해 구형의 입자 형태가 파괴되었고, 기공구조도 크게 변하였다. 산촉매 농도 증가에 의한 구형의 입자형태 파괴 현상은 적었지만 상대적으로 작은 크기의 구형의 마이크로입자가 더 많이 생성되었다. 하지만, 산성조건에서 입자들 간의 강한 응집현상이 나타남에 따라 낱개의 분리되어 있는 단일입자를 얻기 위해서는 초음파 등의 후처리 과정이 필요하였다.