• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.4113-4116
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• 2011

• Macromolecular Research
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• 제16권2호
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• pp.178-181
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• 2008

Polystyrene (PS) nanospheres with a monodisperse size distribution, positive surface charge and high molecular weight were successfully synthesized using various types of metal stearates in an aqueous NaOH medium. The diameter of the PS nanospheres was controlled from 80 to 450 nm by changing the type of metal stearate. It was also found that controlling the NaOH concentration in solution was important for producing monodisperse PS nanoparticles. The nanospheres prepared with zinc stearate possessed a positive surface charge of 60 to 80 mV, confirming that PS particles were functionalized with metal stearates. It is believed that the metal stearates provide PS particles with not only colloidal stability but also a positive surface charge.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.159-166
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• 2012

We have introduced the Pickering emulsion systems to generate novel confining geometries for the selforganization of monodisperse polymer microspheres using nanoparticle-stabilized emulsion droplets encapsulating the building block particles. Then, through the slow evaporation of emulsion phases by heating, these microspheres were packed into regular polyhedral colloidal clusters covered with nanoparticle-stabilizers made of silica. Furthermore, polymer composite colloidal clusters were burnt out leaving nonspherical hollow micro-particles, in which the configurations of the cluster structure were preserved during calcination. The selfassembled porous architectures in this study will be potentially useful in various applications such as novel building block particles or supporting materials for catalysis or gas adsorption.

• 공업화학
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• 제21권1호
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• pp.34-39
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• 2010

${\gamma}-Methacryloxypropyl$이 가진 기능성 그룹으로 silica nanoparticle의 유기변형은 silica의 표면개질로 성공적으로 준비했다. 또한 ethanol 용매에서 AAm을 사용하는 radical 침전중합을 통해서 polyacrylamide를 MPSN nanosphere에 'raft from'방법으로 microsphere가 성공적으로 graft중합되었다. FTIR과 XPS는 ultra-fine silica particle의 표면에서 실리카개질이 공유결합하는 것을 보여주며 SEM분석은 ultra-fine particle과 유기변형된 입자는 각각 25, 30, 35 nm의 크기로 응집작용을 효과적으로 막아주고 나누어줌을 증명할 수 있다는 것을 보여준다.

• 대한기계학회논문집B
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• 제25권9호
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• pp.1175-1182
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• 2001

Chemical compositions of polydisperse SiO$_2$/TiO$_2$multicomponent aggregates were measured for different heights from the burner surface and different mobility diameters of aggregates. SiO$_2$/TiO$_2$multicomponent particles were generated in a hydrogen/oxygen coflow diffusion flame from two sets of precursors: TTIP(titanium tetraisopropoxide), TEOS(tetraethylorthosilicate). To maintain 1:1 mole ratio of TTIP:TEOS vapor, flow rate of carrier gas $N_2$was fixed at 0.6lpm for TTIP, at 0.1lpm for TEOS. In-situ sampling probe was used to supply particles into DMA(differential mobility analyzer) which was calibrated with using commercial DMA(TSI, model 3071A) and classifying monodisperse multicomponent particles. Classified monodisperse particles were collected with electrophoretic collector. The distributions of composition from particles to particle were determined using EDS(energy dispersive spectrometry) coupled with TEM(transmission electron microscope). The chemical(atomic) compositions of classified monodisperse particle were obtained for different heights; z=40mm, 60mm, 80mm. The results suggested that the chemical(atomic) composition of SiO$_2$decreased with the height from burner surface and the composition of SiO$_2$and TiO$_2$approached to the value of 1 to 1 fat downstream. It is also found that the composition of SiO$_2$decreases as the mobility diameter of aggregate increases.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.441-446
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• 2000

Chemical compositions of monodisperse $SiO_2/TiO_2$ multicomponent aggregates were measured for different heights from the burner surface and different mobility diameters of aggregates. $SiO_2/TiO_2$ multicomponent particles were generated in a hydrogen/oxygen coflow diffusion flame from two sets of precursors: TTIP (titanium tetraisopropoxide), TEOS(tetraethylorthosilicate). To maintain 1:1 mole ratio of TTIP:TEOS vapor theoretically, flow rate of carrier gas $N_2$ was fixed at 0.61pm for TTIP, at 0.11pm for TEOS. In situ sampling probe was used to supply particles into differential mobility analyzer(DMA) which was calibrated with using commercial DMA(TSI 3071A) and classifying monodisperse multicomponent particles. Classified particles were collected with electrophoretic collector. The distributions of composition from particle to particle were determined using EDS (energy dispersive spectrometry) coupled with TEM (transmission electron microscope). The chemical (atomic) compositions of classified monodisperse particle were obtained for different heights; z=40mm, 60mm, 80mm. The results suggested that the atomic composition of $SiO_2$ decreased with the height from burner surface and the composition of $SiO_2$ and $TiO_2$ approached to the value of 1 to 1 in far downstream. It is also found that the composition of $SiO_2$ decreases as the mobility diameter of aggregate increases.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3168-3172
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• 2007

As the minimum feature size decreases, control of contamination by nanoparticles is getting more attention in semiconductor process. Cleaning technology which removes nanoparticles is essential to increase yield. A reference wafer on which particles with known size and number are deposited is needed to evaluate the cleaning process. We simulated particle trajectories in the chamber by using FLUENT and designed a particle deposition system which consists of scanning mobility particle sizer (SMPS) and deposition chamber. Charged monodisperse particles are generated using SMPS and deposited on the wafer by electrostatic force. The experimental results agreed with the simulation results well in terms of particle number and deposition area according to particle size, flow rate and deposition voltage.

• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.49-52
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• 2007

As the minimum feature size decrease, control of contamination by nanoparticles is getting more attention in semiconductor process. Cleaning technology which removes nanoparticles is essential to increase yield. A reference wafer on which particles with known size and number are deposited is needed to evaluate the cleaning process. We simulated particle trajectories in the chamber by using FLUENT. Charged monodisperse particles are generated using SMPS (Scanning Mobility Particle Sizer) and deposited on the wafer by electrostatic force. The Experimental results agreed with the simulation results well. We calculate the particles loss in pipe flow theoretically and compare with the experimental results.

• 한국응용과학기술학회지
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• 제21권4호
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• pp.380-387
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• 2004

The preparation of $CaSO_4$ nanoparticle by vesicles formed spontaneously in cationic OTAC and anionic ADS mixed surfactant solution whose ratio is 0.3/0.7 is investigated. Added electrolytes for preparing nanoparticles reduce vesicle size about 200-300 nm comparing with that of pure vesicle whose size is 700-800 nm by DLS. The core of vesicles has 200 nm size and acts as nanoreactors which same size of monodisperse $CaSO_4$ nanopaticles are formed. Although $CaSO_4$ particles are formed at the outer of vesicles, they are very large and amorphous. The formed particles are identified with XRD analysis after separation due to coinciding with $CaSO_4$ particles.

• 폴리머
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• 제27권4호
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• pp.370-376
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• 2003

나노입자의 제조 방법인 개선된 자발적 용매 확산 방법을 이용하여 폴리(DL-락타이드-co-글리콜라이드) 나노입자를 제조하였다. 고분자 용액은 물에 잘 혼합되는 유기 용매인 에탄올과 아세톤의 이종 혼합 용매를 사용하여 제조하였다. 유화제 및 안정제는 우수한 생체적합성을 갖는 PEG-PPG 블록 공중합체를 사용하였다. 최적의 나노입자 제조 조건을 얻기 위하여 나노입자 형성에 영향을 주는 인자들인 안정제의 종류 및 농도, 교반 방법, 물/오일 상의 비, 고분자의 농도 등을 고려하였다. 나노입자 제조 후, 입자의 크기 및 분산도는 광산란 입도 분석기를 이용하여 평가하였다. 제조된 나노입자는 50~200 nm의 크기와 단분산 형태의 크기분포를 보였다. 또한, 유기상과 수용액상에서 이종 혼합 용매와 고분자의 농도에 대한 적당한 조건을 조절함으로써 PLGA 나노입자의 높은 수율과 우수한 물리적 특성을 얻을 수 있었다.