• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.673-674
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• 2006

The influence of several experimental parameters on the formation of stable Alloy 625 nanoparticles dispersion in ethanol was investigated. Several analyzing methods were applied, like transmission profiles measured by Turbiscan, transmission electron microscopy, X-ray diffraction, gas chromatography, and particle size analyzer. The correlation among the increase of particle sizes, caused by nanoparticle coalescence and collision, concentration of dispersant and time was presented and discussed. The optimum conditions for the formation of stable dispersion are evaluated.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.462-463
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• 2006

Monodispersed and nano-sized Ni powders were synthesized from aqueous nickel sulfate hexahydrate $(NiSO_4{\cdot}6H_2O)$ inside nonionic polymer network by using wet chemical reduction process. The sucrose was used as a nonionic polymer network source. The effect of reaction conditions such as the amount of sucrose and a various reaction temperature, nickel sulfate hexahydrate molarity. The influence of a nonionic polymer network on the particle size of the prepared Ni powders was characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and particle size analysis (PSA). The results showed that the obtained Ni powders were strong by dependent of the reaction conditions. In particular, the Ni powders prepared inside a nonionic polymer network had smooth spherical shape and narrow particle size distribution.

• 한국재료학회지
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• 제16권12호
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• pp.739-742
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• 2006

The ${\gamma}-Fe_2O_3$ nano particles in the size range of $5{\sim}30$ nm were prepared by a chemical coprecipitation method. The nano particles were coated with 2nd surfactants for obtaining the water-based. The size effect of ${\gamma}-Fe_2O_3$ nano particles for the ultraviolet protection was investigated. The variation of the UV-Vis transmittance spectra as a function of wavelength for a ${\gamma}-Fe_2O_3$ nano particles were showed red-shifted increase with the particle size. The protective effects of UVA onset at near 469, 494, 591 nm for a particle size of 8.7, 9.1 and 12 nm. It is shown that the ${\gamma}-Fe_2O_3$ nano particles was good materials for protect of UV.

• 한국재료학회지
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• 제17권10호
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• pp.532-537
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• 2007

A series of wet grinding experiments have been carried out using a stirred ball mill to systematically investigate consideration of grinding characteristics. The particle size distribution and median diameter of the grinding consumption power for a given grinding time were considered. Also, the effect of grinding aids on particle size and grinding consumption energy defined as the summation of grinding power was investigated. The grinding aids had influence on the smaller products size and decrease grinding consumption energy because the function of grinding aids were to be attribute to the prevention of agglomeration and ball and grinding chamber wall coating of sample powder. The grinding process seemed to be controlled by the force of agglomeration of the ground products. It was demonstrated that the particle size and grinding consumption energy could be more decreased by the addition of grinding aids.

• 대한의용생체공학회:의공학회지
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• 제43권2호
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• pp.94-101
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• 2022

Recent advancement of micro/nano technology enables the development of diverse micro/nano particle-based delivery systems. Due to the multi-functionality and engineerability, particle-based delivery system are expected to be a promising method for delivery to the target cell. Since the particle-based delivery system should be delivered to the various kinds of target cell, including the cardiovascular system, cancer cell etc., it is frequently decorated with multiple kinds of targeting molecule(s) to induce specific interaction to the target cell. The surface decorated molecules interact with the cell surface expressed molecule(s) to specifically form a firm adhesion. Thus, in this study, the probability of adhesion is estimated to predict the possibility to form a firm adhesion for the multi-ligand decorated particle-based delivery system.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1678-1683
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• 2003

DBD(Dielectric Barrier Discharge) plasma in air is well established for the production of large quantities of ozone and is more recently being applied to aftertreatment processes for HAPs(Hazardous Air Pollutants). Although DBD high electron density and energy, its potential use as nano and sub-micron sized particle charging are not well known. Aim of this work is to determine design and operating parameters of a two-stage ESP with DBD. DBD and ESP are used as particle charger and precipitator, respectively. We measured particle precipitation efficiency of two-stage ESP and estimated ozone decomposition of both pelletized $MnO_2$ catalyst and pelletized activated carbon. To examine the particle precipitation efficiency, nano and sub-micron sized particles were generated by a tube furnace and an atomizer. AC voltage of $7{\sim}10$ kV(rms) and 60 Hz is used as DBD plasma source. DC -8 kV is applied to the ESP for particle precipitation. The overall particle collection efficiency for the two-stage ESP with DBD is over 85 % under 0.64 m/s face velocity. Ozone decomposition efficiency with pelletized $MnO_2$ catalyst or pelletized activated carbon packed bed is over 90 % when the face velocity is under 0.4 m/s in dry air.

• 한국분말재료학회지
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• 제11권3호
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• pp.202-209
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• 2004

In this study, nano-sized powder of Ni-ferrite was fabricated by spray pyrolysis process using the Fe-Ni complex waste acid solution generated during the shadow mask processing. The average particle size of the produced powder was below 100 nm. The effects of the reaction temperature, the inlet speed of solution and the air pressure on the properties of powder were studied. As the reaction temperature increased from 80$0^{\circ}C$ to 110$0^{\circ}C$, the average particle size of the powder increased from 40 nm to 100 nm, the fraction of the Ni-ferrite phase was also on the rise, and the surface area of the powder was greatly reduced. As the inlet speed of solution increased from 2 cc/min. to 10 cc/min., the average particle size of the powder greatly increased, and the fraction of the Ni-ferrite phase was on the rise. As the inlet speed of solution increased to 100 cc/min., the average particle size of the powder decreased slightly and the distribution of the particle size appeared more irregular. Along with the increase of the inlet speed of solution more than 10 cc/min., the fraction of the Ni-ferrite phase was decreased. As the air pressure increased up to 1 $kg/cm^2, the average particle size of the powder and the fraction of the Ni-ferrite phase was almost constant. In case of 3 $kg/cm^2 air pressure, the average particle size of the powder and the fraction of the Ni-ferrite phase remarkably decreased.

• 한국결정성장학회지
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• 제25권5호
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• pp.212-217
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• 2015

본 연구는 해상 양식장 내에 유해 조류로 인해 발생하는 수산 동, 식물의 폐사를 막고, 양식장을 주기적으로 정화하는 폰툰 시스템 내의 멤브레인 층(Membrane Layer)의 생물오손(Biofouling)을 막고자, ML에 적용되는 인공경량골재 및 골재의 구조에 따른 미생물 흡착을 비교하고자 지오폴리머에 은 나노 입자를 코팅하여 생물오손 정도를 확인하고 그 능력을 평가하였다. 이후 코팅에 따른 미생물 기능 억제 능력을 확인하고자 항균 테스트를 실시하였으며, 한국해양과학기술원 남해연구소 앞바다에 설치하여 생물오손 정도와 무게변화율을 관찰하였다. 항균 테스트 결과 은 나노 입자를 코팅한 인공경량골재에서 99.99 %의 세균 감소율을 확인하였으며, 생물오손 정도를 관찰한 결과 2개월부터 은 나노 입자의 효과에 의해 생물오손 정도가 억제되는 것을 확인하였다. 은 나노 입자 코팅에 의한 생물오손 억제기간은 인공경량골재에서 5개월, 지오폴리머에서 3개월 미만으로 나타났으며, 따라서 은 나노 입자가 코팅된 인공경량골재가 효과적으로 생물오손을 감소시킬 수 있는 친환경적이며 효과적인 방법임을 알 수 있었다.

• 자원리싸이클링
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• 제14권6호
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• pp.21-27
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• 2005

국내 은 함유 폐자원의 고부가가치 제품화를 위한 연구의 일환으로써 sodium formaldehydesulfoxy와 ascorbic acid를 각각 환원제로 사용한 Ag 나노분발의 제조실험을 수행하였다. Ag수용액은 질산은을 소정 농도로 증류수에 용해시켜 사용하였으며, Ag미립자의 응집방지를 위한 분산제로는 Tamol NN8906, PVP, SDS 및 caprylic acid를 각각 사용하었다. 환원반응을 통하여 제조한 Ag 미립자는 입도분석기 및 TEM측정을 통하여 morphology와 평균입도를 측정하였다. sodium formaldehydesulfoxylate 에 의한 은의 환원을 위해서는 이론치의 1.4배를 첨가해 주어야 하는 것으로 나타났으며, ascorbic acid와는 달리 생성된 Ag 입자가 너무 크게 성장하는 문제점이 있었다. 분산제에 따른 Ag 입자의 특성을 살펴본 결과, Tamol 및 PVP를 사용한 경우에는 bimodal distribution을 보였으나, SDS 와 caprylic acid의 경우에는 수십 nm에서 $100{\mu}m$에 이르는 매우 broad한 입도분포를 보였다.

• 공업화학
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• 제21권6호
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• pp.670-675
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• 2010

나노실리카볼 입자를 합성하고 표면에 비닐기를 부여하는 합성 연구를 통해 다양한 크기로 조절이 된 유-무기하이브리드 입자인 비닐-나노실리카볼이 합성되었다. 다양한 크기의 비닐-나노실리카볼 입자를 상업적으로 적용되고 있는 아크릴-멜라민 클리어코트에 후첨시키고 경화시켰을 때, 클리어코트의 광택도 증가 및 유지 특성에 대해 연구하였다. 실리카볼 입자가 250 nm 정도인 경우 Matting effect에 의한 광택도 감소가 관측되었으나 20~30 nm로 작아지면 광택도 유지 효과가 약 7%까지 증가하였다. 나노실리카볼 대신 상업용 친수 실리카 Aerosil 200 (Hydrophilic fumed silica, 평균입도 12 nm, Degussa)을 사용하여 비닐- fumed 실리카 화합물을 합성하여 클리어코트에 적용하면 광택도 유지 효과가 약 2% 정도만 증가하였다.