• Elastomers and Composites
• /
• 제45권1호
• /
• pp.7-11
• /
• 2010

본 논문에서는 polyethyleneimine (PEI)를 커플링제로 사용하여 간단한 공정을 통하여 아세틸렌 블랙/실리카 복합체 입자를 제조하였다. 복합체 입자는 PEI를 아세틸렌 블랙 표면에 흡착시키고 졸-겔 합성공정을 통하여 실리카를 아세틸렌 블랙 위에서 합성하는 두단계 공정을 통하여 제조되었다. 복합체 입자의 모폴로지 분석 결과 실리카가 아세틸렌 블랙위에 존재하는 core-shell 구조를 확인하였으며, 표면에 상당한 미세기공이 존재함을 알 수 있었다.

• 한국산학기술학회논문지
• /
• 제12권11호
• /
• pp.5365-5369
• /
• 2011

실리카-골드 복합체 입자를 함침법에 의하여 합성하였고, 용매와 전구체가 실리카-골드 입자 합성에 미치는 영향이 연구되었다. 구형 실리카 입자를 지지체로 하여 PVP, hydrogentetrachloroaurate(III) hydrate 수용액을 전구체로 사용했을 때, 연한 분홍색 색상을 띄는 실리카-골드 입자가 성공적으로 합성되었다. 합성된 복합체의 특성은 FE-SEM, FE-TEM과 XRD를 통하여 분석하였다.

• 접착 및 계면
• /
• 제11권3호
• /
• pp.112-119
• /
• 2010

PMMA와 PBA core 제조 시 개시제는 APS를, 유화제 SDBS의 농도를 0.01에서 0.03 wt% 일 때 전환율이 95.8과 92.3%로 가장 우수하였으며, core-shell 복합입자의 제조 시에는 SDBS의 농도 0.02 wt% 일 때 PMMA/PBA core-shell 복합입자는 전환율이 90.0%, PBA/PMMA core-shell 복합입자는 89.0%가 되었다. FT-IR 분석과 GPC에 의한 평균분자량 측정을 통해 core와 shell 단량체들이 중합되어 있음을 확인하고, 복합입자의 형태는 상온에서의 필름형성정도와 TEM 분석으로 확인하였다. DSC에 의해 유리전이온도를 측정함으로써 일반 공중합체와는 달리 2개의 유리전이온도가 존재하여 core-shell 복합입자가 형성되었음을 알 수 있고, 각각의 core-shell 복합입자의 인장강도와 신율의 측정을 통해 고기능성 접착바인더로서의 사용가능성을 확인하였다.

• 한국표면공학회지
• /
• 제25권2호
• /
• pp.73-81
• /
• 1992

The composite coating of suspended inert particles $\alpha$-Al2O3 and copper from acid sulphate bath was investigated at the Rotating Disk Electrode. Effects of rotation speeds of electrode, physical properties of electrolyte, the size and concentration of suspended particles on the codeposition ratio of Al2O3 and the enhancement of mass transfer of copper ions were examined. Particularly, new experimental method for the measurement of the codeposition ratio was suggested and also the characteristics of the composite coating layer were measured by Rutherford Backscattering Spectrometry. Mass transfer of suspended particles system were increased up to 40% more than those of without suspended particles system. Optimum conditions of current density, hydrodynamics of RDE, and particles concentration showing maximum codeposition ratio were appeared in our experimental ranges. It was shown that the suspended inert particles were codeposited mainly near the surface of the composite coating layer.

• Bulletin of the Korean Chemical Society
• /
• 제35권11호
• /
• pp.3303-3306
• /
• 2014

A facile and effective approach has been developed to prepare hybrid hollow microspheres, via consecutive processes of pickering mini-emulsion polymerization for core-shell formation, and calcination of the sacrificial core. The resulting hollow composite particles have mono-layered shells. The morphology and size characteristics of synthesized composite particles were investigated, using dynamic light scattering (DLS) and scanning electron microscopy (SEM) measurements.

• 공업화학
• /
• 제29권4호
• /
• pp.425-431
• /
• 2018

UV 및 블루라이트를 차단하는 세륨 옥사이드 나노 입자와 다공성 실리카와의 복합입자를 건식 코팅 공정을 통해 제조하였다. 실리카와 세륨 옥사이드 간 혼합 비율과 메카노 퓨전 장치의 챔버 회전속도 등의 제조 조건을 달리하여 여러 복합입자를 만든 후, 입자 표면 형태를 SEM으로 관측 비교하고 XRF을 통해 복합입자의 조성을 분석하였다. 세륨 옥사이드를 실리카와 함께 복합입자로 만들어 물에 분산시키면 현탁 용액의 투명도가 높아지고 분산 안정성이 향상되었다. 또한 파우더의 유동성과 발림성이 개선되었다. 본 연구를 통해 세륨 옥사이드/실리카 복합입자가 자외선 및 블루라이트를 차단하는 기능성 화장품 소재로 사용 가능함을 확인하였다.

• 한국입자에어로졸학회지
• /
• 제6권2호
• /
• pp.61-67
• /
• 2010

In this paper, we describe a new method to form polymer thin films, in which carbon nanotubes (CNTs) are homogeneously distributed so that they can strengthen the mechanical property of resulting polymer film. To do so, we first homogeneously mixed CNTs with polymer in a DMF solvent. With the assistance of ultrasonic nebulizer, the polymer/CNT solution was then aerosolized into micro-sized droplets and finally turned into solidified polymer/CNT composite particles by gas-phase drying process. As the results of SEM and TEM analysis, CNTs were found to be homogeneously immobilized in the polymer matrix particles due to rapid drying process in the gas phase. For comparison purpose, (i) the polymer/CNTs composite particles prepared by aerosol processing method and (ii) polymer/CNTs sheets prepared by simple solution-evaporation method were employed to form polymer/CNTs composite thin films using a hot press. As the result, the aerosol processing of composite particles was found to be a much more effective method to form homogeneously distributed-CNTs in the polymer matrix thin film.

• 한국분말재료학회지
• /
• 제23권3호
• /
• pp.195-201
• /
• 2016

Composite materials consisting of pure aluminum matrix reinforced with different amounts of graphite particles are successfully fabricated by mechanical ball milling and spark plasma sintering (SPS) processes. The shrinkage rates of the composite powders vary with the amount of graphite particles and the lowest shrinkage value is observed for the composite with the highest amount of graphite particles. The current slopes of time increase with increase in the amount of graphite particles whereas the current slopes of temperature show the opposite trend. The highest thermal conductivity is achieved for the composite with the least amount of graphite particles. Therefore, the thermal properties of the composite materials can be controlled by controlling the amount of the graphite particles during the SPS process.

• Carbon letters
• /
• 제11권2호
• /
• pp.107-111
• /
• 2010

We prepared the amine epoxy adducts (AEA)/thin multiwalled carbon nanotubes (TWCNTs) composite particles using nonsolvent based methods including dry mechano-chemical bonding(MCB) process and supercritical fluid (SCF) process. The resulting TWCNTs/AEA composite particles have been used as curing agents for urethane modified bispheol A type epoxy resin. The thermal, thermomechanical properties of the epoxy resins cured with TWCNTs/AEA composite particles were measured by DMA and the dispersion of CNT was characterized by SEM. Because of high degree of CNT dispersion, thermal and mechanical properties of the epoxy resin cured with TWCNTs/AEA composite particles prepared by SCF process are better than those cured with mechano-chemically prepared TWCNTs/AEA composite particles.

• 대한화장품학회지
• /
• 제25권4호
• /
• pp.43-50
• /
• 1999

The planarized $SiO_2$ particles were prepared by two-step reduction method of making much smaller particles, micron-sized ones, to improve spreadability, adherence, and smoothness. Various pigments known as flaky extender usually have terrace layers on their surfaces, but $SiO_2$ particles in this study exhibit a smooth surface structure. These single $SiO_2$ particles were used as core particles to prepare the composite particles coated with ultra fine $TiO_2$ particles by a homogeneous precipitation method. The thickness and the morphology of the deposited $TiO_2$ layers could be modified by adjusting the reactant concentrations, the reaction time and the temperature. The characteristics of $SiO_2/TiO_2$ composite in the field of color cosmetics are to give an UV-cut effect and to enhance the chroma of human skin color, one of optical properties.