초임계 메탄올을 이용한 표면개질된 세리아 나노입자의 합성

안기호 ( Ki He Ahn ),신내철 ( Nae Chul Shin ),김민수 ( Min Soo Kim ),윤용석 ( Yong Sak Youn ),홍기영 ( Gi Young Hong ),이윤우 ( Youn Woo Lee ) 한국화학공학회 2012 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.50 No.4

Ceria is one of the most important catalytic materials which can be used in three-way catalysts, waste water treatment, petroleum refining, etc. So far, many methods have been studied to produce ceria nanoparticles. In this study, ceria nanoparticles were prepared via solvothermal synthesis using supercritical methanol in short reaction time using a batch reactor. The size of synthesized ceria nanoparticles in supercritical methanol is 6 nm without capping agent, which is smaller than that made in supercritical water at the same conditions of 400 oC and 30 MPa. Size difference results from density and critical point difference between water and methanol and slow reaction rate at the surface of ceria particles in supercritical methanol which reduces crystal growth rate. Several organic compounds were added to modify the surface of ceria nanoparticles, and in-situ surface modification was confirmed by FT-IR and TGA analysis. Surface modified ceria nanoparticles have excellent dispersibility in organic solvent. Size and shape of surface modified ceria particles can be controlled by adjusting molar ratio of modifier to precursor and selection of modifier.

Ceria-Zirconia Nanoparticles as an Enhanced Multi-Antioxidant for Sepsis Treatment

소민,현택환 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

The two oxidation states of ceria nanoparticles, Ce³⁺ and Ce⁴⁺, play a pivotal role in scavenging reactive oxygen species (ROS). In particular, Ce³⁺ is greatly responsible for eliminating O₂ ^- and ㆍOH that are associated with inflammatory response and cell death. Here, we report the synthesis of 2 nm ceria-zirconia nanoparticles (CZ NPs) possessing a higher ratio of Ce³⁺-to-Ce⁴⁺ and faster shifting from Ce⁴⁺ to Ce³⁺ than those exhibited by ceria nanoparticles. The obtained Ce_0.7Zr_0.3O₂ (7CZ) NPs markedly enhance their ROS scavenging performance, thus regulating inflammatory cells in a very low dose which is not possible with ceria nanoparticles. Furthermore, 7CZ NPs are demonstrated to be powerful for reducing mortality and systemic inflammation in two sepsis models. These findings suggest that 7CZ NPs have the potential as a therapeutic nanomedicine for treating ROS-related inflammatory diseases.

Drug-Loaded Modified Ceria-Zirconia Nanoparticles as an Enhanced Efficiency for Liver Disease Treatment

홍상은,김옥희,홍하은,김세준,윤국로 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Chemotherapy is one of the significant approach for in vivo disease includes cancer treatment but has important challenges, such as cancer cell resistance and various side effect to normal tissue. Here, we have designed and synthesized an effective liver disease treatment agent based on monodisperse ceria-zirconia nanoparticles, which are loaded with drug (which was a typically drug for hepatocellular carcinoma (HCC)) and modified with binding to the hepatocarcinoma A54 peptide (sequence AGKGTPSLETTP) and poly(ethylene glycol) on their surface (S-A54/P-CeZr). The physicochemical properties were confirmed by FE-TEM (Field-emission Transmission Electron Microscope), EDS (Energy-Dispersive X-ray Spectroscopy), DLS(Dynamic Light Scattering), TGA(Thermogravimetric Analysis), 1H-NMR(1H Nuclear Magnetic Resonance) analyses.

Structural and electrochemical properties of the catalytic CeO₂ nanoparticles-based PEO ceramic coatings on AZ91 Mg alloy

Ur Rehman, Zeeshan,Uzair, Muhammad,Lim, Hyung Tae,Koo, Bon Heun Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.726 No.-

<P><B>Abstract</B></P> <P>CeO<SUB>2</SUB> nanoparticles are highly recognized for their catalytic role in various energy applications. The phenomenon of switching between the stable oxidation states (+4, +3) of cerium is considered as the main cause of its catalytic activity. In this report cerium rich ceramic coating was prepared on AZ91D magnesium alloy. From the EDS analysis, it was confirmed that CeO<SUB>2</SUB> particles were preferentially sited in the pores, cracks and the radial zones around the pores. The presence of ceria and cerium based intermetallic species in the XRD pattern established the generous involvement of the ceria nanoparticles in the PEO reactions. The Raman results showed particular bands related to the catalytic ceria and supported the XRD outcomes. Due to the compact and cerium-rich inner layer due to its optimum catalytic role, the coating prepared for 30 min was found to have the highest corrosion resistance measured through EIS and potentiodynamic polarization experiments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PEO coatings were produced on AZ91 Mg alloy in CeO<SUB>2</SUB> nanoparticle based solution. </LI> <LI> XRD, EDS and Raman results confirmed the chemical involvement of CeO<SUB>2</SUB> particles. </LI> <LI> Increasing the processing time ∼30 min, revealed the benign catalytic role of CeO<SUB>2</SUB>. </LI> <LI> Enhanced corrosion resistance ∼706.4 × 10<SUP>3</SUP> Ω/cm<SUP>2</SUP> and nobility ∼ −0.36 V was achieved. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The involvement of various electrolyte species in the PEO process.</P> <P>[DISPLAY OMISSION]</P>

CeO2/TiO2 코어-쉘 나노입자의 합성

문영길,박장우,김상헌 한국응용과학기술학회 2017 한국응용과학기술학회지 Vol.34 No.4

In this study, CeO2/TiO2 nanoparticle with structure of core and shell was synthesized by growing TiO2 onto the surface of CeO2 according to hydrolysis of Ti(SO4)2. Reaction time, temperature, concentration of CeO2 slurry, pH control of Ti(SO4)2 were optimized about synthesis of CeO2/TiO2 core-shell nanoparticle. It was found that optimal mole ratio range of CeO2:TiO2 was 1:0.2~1.1, the optimal concentration of CeO2 slurry was 1 %, and the optimal reaction temperature was 50oC. The optimal concentration of CeO2 slurry could be increased up to 10 % by adjusting the pH of Ti(SO4)2 to 1 using NH4OH and adding to CeO2 slurry. If reaction was carried at 80oC or higher, the separated TiO2 particles were obtained instead of CeO2/TiO2 core-shell nanoparticles. The optimal reaction temperature was 50oC at which good shaped core-shell structure of CeO2/TiO2 was obtained. 본 연구에서는 CeO2 표면에 Ti(SO4)2의 가수 분해를 이용하여 TiO2를 성장시켜 코어-쉘 구조를 가지는 세라믹 나노입자를 합성 하였다. CeO2/TiO2 코어-쉘 합성에서는 CeO2:TiO2의 몰비, 반응시간, 반응 온도, CeO2 슬러리 농도, Ti(SO4)2의 pH 조절을 통하여 코어-쉘 구조를 가지는 최적의 합성 조건을 찾았다. CeO2:TiO2의 최적의 몰비는 1:0.2~1.1, 최적의 반응 시간은 24 시간, 최적의 CeO2 슬러리 농도는 1%, 최적의 반응 온도는 50℃임을 알 수 있었다. NH4OH 수용액을 이용하여 Ti(SO4)2의 pH를 1로 맞추어 CeO2 슬러리에 적하하면 10%의 농도를 가지는 CeO2 슬러리에서도 CeO2/TiO2 코어-쉘 나노 입자를 합성할 수 있었다. 80℃이상의 높은 온도에서 반응을 시키면 CeO2/TiO2 코어-쉘 구조가 아닌 독립된 TiO2 나노 입자를 형성함을 알 수 있었다. 최적의 반응 온도는 50℃로서 가장 좋은 구조의 CeO2/TiO2 코어-쉘이 합성되었다.

Increase in Ce³⁺ Concentration of Ceria Nanoparticles for High Removal Rate of SiO₂ in Chemical Mechanical Planarization

Kim, Kijung,Yi, Dong Kee,Paik, Ungyu The Electrochemical Society 2017 ECS journal of solid state science and technology Vol.6 No.9

<P>Ceria nanoparticles (NPs) are used as abrasives for silicon dioxide (SiO<SUB>2</SUB>) chemical mechanical planarization (CMP) due to the strong chemical bonds between the Ce<SUP>3+</SUP> ions of ceria NPs and the hydrated silicate species on the surface of SiO<SUB>2</SUB> films. However, the limited concentration of Ce<SUP>3+</SUP> ions in ceria NPs remains a major challenge for this application. Herein, we report a simple strategy to synthesize ceria NPs with high concentrations of Ce<SUP>3+</SUP> ions for enhanced adsorption reactions with silicate anions. Three types of ceria NPs approximately 70 nm in size were synthesized via the aggregation of different sized primary NPs. As the particle size of the primary NPs decreased from 70 nm to 5 nm, the Ce<SUP>3+</SUP> concentration of the ceria NPs increased from 15.6 to 24.0%. The adsorption isotherm fits the Freundlich model and the constants of adsorption capacity (K<SUB>F</SUB>) and adsorption intensity (1/n) indicate that the adsorption affinity for silicate anions increased with increasing Ce<SUP>3+</SUP> concentration. The increase in Ce<SUP>3+</SUP> concentration led to an increase in the chemical adsorption between ceria NPs and silicate anions, resulting in a high removal rate of SiO<SUB>2</SUB> during CMP.</P>

Mitochondria-Targeting Ceria Nanoparticles as Antioxidants for Alzheimer’s Disease

Kwon, Hyek Jin,Cha, Moon-Yong,Kim, Dokyoon,Kim, Dong Kyu,Soh, Min,Shin, Kwangsoo,Hyeon, Taeghwan,Mook-Jung, Inhee American Chemical Society 2016 ACS NANO Vol.10 No.2

<P>Mitochondrial oxidative stress is a key pathologic factor in neurodegenerative diseases, including Alzheimer's disease. Abnormal generation of reactive oxygen species (ROS), resulting from mitochondrial dysfunction, can lead to neuronal cell death. Ceria (CeO2) nanoparticles are known to function as strong and recyclable ROS scavengers by shuttling between Ce3+ and Ce4+ oxidation states. Consequently, targeting ceria nano particles selectively to mitochondria might be a promising therapeutic approach for neurodegenerative diseases. Here, we report the design and synthesis of triphenylphosphonium-conjugated ceria nanoparticles that localize to mitochondria and suppress neuronal death in a SXFAD transgenic Alzheimer's disease mouse model. The triphenylphosphonium-conjugated ceria nanoparticles mitigate reactive gnosis and morphological mitochondria damage observed in these mice. Altogether, our data indicate that the triphenylphosphoniuni-conjugated ceria nanoparticles are a potential therapeutic candidate for mitochondrial oxidative stress in Alzheimer's disease.</P>

Morphologically Controlled Preparation of Ceria Nanoparticles for Biomedical Applications

남세현,( Tranminhngoc ),유효종 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.-

Large-Scale Synthesis of Water Dispersible Ceria Nanocrystals by a Simple Sol–Gel Process and Their Use as a Chemical Mechanical Planarization Slurry

Yu, Taekyung,Park, Yong Il,Kang, Min-Cheol,Joo, Jin,Park, Jin Kyung,Won, Ho Youn,Kim, Jae Jeong,Hyeon, Taeghwan WILEY-VCH Verlag 2008 European journal of inorganic chemistry Vol.2008 No.6

<P>Ceria nanocrystals with a cube shape were synthesized from the hydrolytic sol–gel reaction of cerium salt in the presence of oleylamine. The overall synthetic process is very simple and readily applicable to the large-scale synthesis of tens of grams of product in a single reaction in air. These ceria nanocrystals are readily dispersible in aqueous media without the addition of any extra dispersing agent. The aqueous dispersion of the ceria nanocrystals was successfully used as a chemical mechanical polishing slurry, and it exhibited high removal selectivity between silicon oxide and silicon nitride at pH 7.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)</P> <B>Graphic Abstract</B> <P> <img src='wiley_img/14341948-2008-2008-6-EJIC200700979-fig000.gif' alt='wiley_img/14341948-2008-2008-6-EJIC200700979-fig000'> </P>

용매열 공정을 이용한 세리아(CeO₂) 나노분말의 합성 및 분산거동

임태섭,옥지영,최연빈,김봉구,손정훈,정연길,Lim, Tae Seop,Ock, Ji Young,Choi, Yeon Bin,Kim, Bong Gu,Son, Jeong Hun,Jung, Yeon Gil 한국재료학회 2020 한국재료학회지 Vol.30 No.7

CeO₂ nanoparticles, employed in a lot of fields due to their excellent oxidation and reduction properties, are synthesized through a solvothermal process, and a high specific surface area is shown by controlling, among various process parameters in the solvothermal process, the type of solvent. The synthesized CeO₂ nanoparticles are about 11~13 nm in the crystallite size and their specific surface area is about 65.38~84.65 ㎡/g, depending on the amount of ethanol contained in the solvent for the solvothermal process; all synthesized CeO₂ nanoparticles shows a fluorite structure. The dispersibility and microstructure of the synthesized CeO₂ nanoparticles are investigated according to the species of dispersant and the pH value of the solution; an improvement in dispersibility is shown with the addition of dispersants and control of the pH. Various dispersing properties appear according to the dispersant species and pH in the solution with the synthesized CeO₂ nanoparticles, indicating that improved dispersing properties in the synthesized CeO₂ nanoparticles can be secured by applying dispersant and pH control simultaneously.