• 한국고분자학회지:고분자과학과기술
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• 제8권3호
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• pp.316-325
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• 1997

• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.503-506
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• 1998

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2008년도 Asian Magnetics Conference
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• pp.228.2-228.2
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• 2008

• Current Applied Physics
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• 제18권11호
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• pp.1410-1414
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• 2018

Magnetic nanoparticles (MNP) have attracted considerable interest in many fields of research and applied science due to their impressive properties. In the past, especially biomedical problems have promoted the development of MNPs. For technical applications e.g. wastewater treatment and absorption of electromagnetic waves, the existing synthesis approaches are too expensive and/or the producible quantities are too low. In this work we present a method for simple preparation of size-controlled magnetic iron oxide nanoparticles by electroerosion dispersion (EED) of carbon steel in water. We describe the synthesis method, the laboratory installation and discuss the structural, chemical and electromagnetic properties of the synthetized EED powders as well as their applicability for microwave absorption compared to other available ferrite powders.

• 한국재료학회지
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• 제25권2호
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• pp.95-99
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• 2015

$NiAl_2O_4$ nanoparticle was synthesized by a reverse micelle processing for inorganic pigment. $Ni(NO_3)_2{\cdot}6H_2O$ and $Al(NO_3)_3{\cdot}9H_2O$ were used for the precursor in order to synthesize $NiAl_2O_4$ nanoparticles. The aqueous solution, which consisted of a mixing molar ratio of Ni/Al, was 1:2 and heat treated at $800{\sim}1100^{\circ}C$ for 2h. The average size and distribution of synthesized $NiAl_2O_4$ powders are in the range of 10-20 nm and narrow, respectively. The average size of the synthesized $NiAl_2O_4$ powders increased with an increasing water-to-surfactant molar ratio and heating temperature. The crystallinity of synthesized $NiAl_2O_4$ powder increased with an increasing heating temperature. The synthesized $NiAl_2O_4$ powders were characterized by X-ray diffraction analysis(XRD), a field emission scanning electron microscopy(FE-SEM), and a color spectrophotometer. The properties of synthesized powders were affected as a function such as a molar ratio and heating temperature. Results indicate that synthesis using a reverse miclle processing is a favorable process to obtain $NiAl_2O_4$ spinels at low temperatures. The procedure performed suggests that this new synthesis route for producing these oxides has the advantage of being fast and simple. Colorimetric coordinates indicate that the pigments obtained exhibit blue colors.

• 한국세라믹학회지
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• 제56권2호
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• pp.111-129
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• 2019

Recently, all-solid-state batteries (ASSBs) have attracted increasing interest owing to their higher energy density and safety. As the core material of ASSBs, the characteristics of the solid electrolyte largely determine the performance of the battery. Thus far, a variety of inorganic solid electrolytes have been studied, including the NASICON-type, LISICON-type, perovskite-type, garnet-type, glassy solid electrolyte, and so on. The garnet Li₇La₃Zr₂O₁₂ (LLZO) solid electrolyte is one of the most promising candidates because of its excellent comprehensively electrochemical performance. Both, experiments and theoretical calculations, show that cubic LLZO has high room-temperature ionic conductivity and good chemical stability while contacting with the lithium anode and most of the cathode materials. In this paper, the crystal structure, Li-ion transport mechanism, preparation method, and element doping of LLZO are introduced in detail based on the research progress in recent years. Then, the development prospects and challenges of LLZO as applied to ASSBs are discussed.

• 한국세라믹학회지
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• 제38권10호
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• pp.921-927
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• 2001

카올린으로부터 알루미나를 추출 노는 한성에 미치는 초음파 효과를 조사하기 위하여 반응시간, 반응온도 및 산농도의 동일한 조건하에서 알루미나 추출 및 합성에 초음파 조사법과 재래식법을 사용하였다. 재래식법에 비하여 초음파 조사법은 $60{\sim}80^{\circ}C$, $1{\sim}6\;h$ 및 $1{\sim}5\;M$ ${H_2}{SO_4}$와 같은 다양한 조건하에서 알루미나 추출을 촉진시켰다. 초음파 조사법 및 재래식법에 의해 합성된 침전물과 하소된 시료들의 특성들이 DTA/TG, XRD, SEM, PSA, BET 등에 의해 분석되어졌다. 특히, 재래식법으로 합성된 하소시료들에 비하여 초음파 조사법으로 합성된 시료들은 상대적으로 입자 크기는 작고, 비표면적이 큰 특성을 자지고 있었다.

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1523-1524
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• 2006

• Bulletin of the Korean Chemical Society
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• 제20권8호
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• pp.875-878
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• 1999

A new concept ？？soft solution processing？？ has been introduced to fabricate advanced solid state materials in an economical, environmentally friendly, and energy and material efficient way. The prepared films show the desired and prospective properties despite of low temperature synthesis and no post-synthesis annealing. Successful examples demonstrate that soft solution processing is capable of preparing advanced materials with planned properties through the easy control of reaction conditions in a suitable aqueous solution in a single synthetic step without huge energy consumption and without any sophisticated equipment.

• 한국세라믹학회지
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• 제25권4호
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• pp.357-363
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• 1988

Ccompaction and sintering behavior of highly pure PSZ powders were investigated by laying the stress on the granulation processes. The particle size of coprecipitated PSZ powder was so fine that the agglomeration was severely formed during drying and calcing step and by this agglomeration differential sinering was occurred. The methanol dispersion of precipitates was the good method of avoiding severe agglomeration formed during drying process because of small surface tension than water. But perfect deagglomeraton was not possible due to high surface area of powders. So homogenization by granulation was needed, and among the method spray granulation was the most desirable to obtain homogeneous compacts and subsequent flaw-free ceramics.