Low temperature synthesis of ultrafine α-Al2O3 powder by a simple aqueous sol–gel process

Li, Jiang; Pan, Yubai; Cheng, Xuesen; Ge, Qiming; Guo, Jingkun

doi:10.1016/j.ceramint.2005.04.015

Cited by 221 publications

(92 citation statements)

References 11 publications

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“…These powders can be synthesized by various routes. 3,4,[6][7][8][9][10] We have shown that the use of M 2+ -doped γ-aluminas synthesized through a polyhydoroxoaluminum (PHA) sol-gel process were very effective for obtaining a fine grain size upon sintering due to an intimate mixing of dopants at an atomic level. 3,11 Among the divalent cation dopants reported in our previous study, Ca 2+ is by far the best dopant for suppressing the grain growth of α-alumina upon heating.…”

Section: Introductionmentioning

confidence: 99%

Densification of Ca-doped alumina nanopowders prepared by a new sol–gel route with seeding

Odaka

Yamaguchi

Fujita³

et al. 2008

Journal of the European Ceramic Society

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This paper demonstrates that the Ca-doped alumina nanopowders prepared by a new sol-gel route using polyhydoxoaluminum (PHA) and CaCl 2 solutions under α-alumina seeding represent a viable option for producing fine-grained ceramics. Appropriate conditions for producing Ca-doped alumina nanopowders suitable for low-temperature finer-grained densification were 0.10 mol% Ca-doping, 5 mass% α-alumina seeding and a calcination temperature of 900˚C. These conditions led to the formation of new nano-sized alumina powders, which consisted of ~80 nm α-alumina particles and γ-alumina nanoparticles. Using these Ca-doped nanopowders, fully densified alumina ceramics with a uniform microstructure composed of fine grains with an average grain size of 0.66 μm could be obtained at 1375˚C.Clearly, the Ca-doped nanopowders obtained here through the proposed sol-gel route are very suitable for fabricating dense, fine-grained alumina ceramics because an undoped sample with 5 mass% seeds led to a microstructure with an average grain size of 1.39 μm at 1375˚C.

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Section: Introductionmentioning

confidence: 99%

Densification of Ca-doped alumina nanopowders prepared by a new sol–gel route with seeding

Odaka

Yamaguchi

Fujita³

et al. 2008

Journal of the European Ceramic Society

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“…Various chemical methods such as spray pyrolysis, 4 precipitation, 5 sol-gel, 6 hydrothermal 7 and combustion synthesis have been employed to synthesize ultrafine Al 2 O 3 powders. 8 Combustion synthesis is particularly a simple, safe and rapid production process wherein the main advantages are energy and time saving. This quick, straightforward process can be used to synthesize homogeneous, high-purity, crystalline oxide ceramic powders including ultrafine alumina powders with a broad range of particle sizes.…”

Section: Introductionmentioning

confidence: 99%

Taguchi Optimization for Combustion Synthesis of Aluminum Oxide Nano‐particles

Edrissi

Norouzbeigi

2008

Chin. J. Chem.

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Nano-structured aluminum oxide powders were prepared by a combustion synthesis method utilizing serine as a new fuel. The product was sonicated to obtain nano powders. A Taguchi L-4 statistical design of combustion synthesis was utilized to optimize the production of γ-alumina powder. The product was characterized by XRD, BET, SEM, EDX and LLS. Nano crystalline γ-alumina with crystal sizes between 4.26 and 5.47 nm and α-Al 2 O 3 powders with crystal sizes 24.51 and 28.62 nm were obtained by the combustion synthesis. The specific surface area was measured by a BET method to be 75.21 m 2 /g. The average particle size after sonication of product, observed by LLS, was 79.32 nm.

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“…Alumina nanoparticles were synthesized by sol-gel method using a 1M solution of nonahydrate aluminium nitrate Al(NO 3 ) 3 ·9H 2 O in distilled water (Li, Pan, Xiang, Ge, & Guo, 2006). In a typical procedure, 200 mL of 1M citric acid were added to 200 mL of 1M Aluminium Nitrate solution.…”

Section: Synthesis and Characterization Of Oleic Acid-coated Alumina mentioning

confidence: 99%

Evaluation of colloidal stability, kinematic viscosity and flash point of B10 Diesel/Biodiesel blends using nanostructured additives based on Al2O3 and oleic acid

Herrera

Ojeda

Peñaloza

et al. 2017

CT&F Cienc. Tecnol. Futuro

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A lumina nanoparticles were synthesized by sol-gel method and submitted to thermal treatment at 750 and 1000 °C. X-ray diffraction was used to determine crystal formation with sizes up to 280 nm. To achieve stable suspensions, a nano-additive was mixed with the diesel/biodiesel blends along with oleic acid surfactant to obtain concentrations of nano-additives at 10 and 20 ppm. For this, alumina nanoparticles were firstly mixed with 20 mL of oleic acid by using an ultrasonicator. Then, this mixture was heated at 80°C under constant agitation for 1 hour, and it was subsequently submitted to ultrasound for 30 minutes. Colloidal stability was evaluated according to Deryaguin-Landau-Verwey-Oberbeek (DLVO) theory by analyzing the total interaction energy of the system. Effects on the kinematic viscosity and flash point of the B10 blend were determined according to ASTM D-445 and ASTM D-93 regulations. The application of nano-additives in biodiesel blends showed an increase of the kinematic viscosity from 2.75 cSt to 3.33 cSt at 40°C with 20 ppm of nanoparticles in the B10 blend, while flash point increased from 65 °C to 66 °C. These results could represent a beneficial effect for engines performance due to their better lubricant capacity. On the other hand, fuels with high enough flash point are easy to handle for transportation and storage. Then, the implementation of nano-additives represents a good opportunity for the biofuels industry. ABSTRACTHow to cite: Herrera, Adriana., Ojeda, K.A., Peñaloza, A.D. Rincón, A. Evaluation of Colloidal Stability, Kinematic Viscosity and Flash Point of B10 Diesel/Biodiesel Blends using Nano-structured Additives based on Al2O3 and Oleic Acid (2017 72L as nanopartículas de Alúmina fueron sintetizadas por el método de sol-gel y sometidas a un tratamiento térmico a 750 y 1000 °C. Se utilizó la técnica de difracción de rayos-X para determinar la formación de cristales con tamaños de hasta 280 nm. Con el propósito de producir suspensiones estables, el nano-aditivo fue mezclado con una solución de diesel/biodiesel usando ácido oleico como un surfactante, obteniendo concentraciones de nano-aditivos de 10 y 20 ppm. Para esto, las nanopartículas de Alúmina se mezclaron primero con 20 mL de ácido oleico usando un baño de ultrasonido. Luego, la mezcla se calentó a 80°C bajo agitación constante por 1 hora, y subsecuentemente se llevó al ultrasonido por 30 minutos. La estabilidad coloidal se evaluó de acuerdo a la teoría de Deryaguin-Landau-Verwey-Oberbeek (DLVO) analizando la energía total de interacción del sistema. Los efectos sobre la viscosidad cinemática y el punto de inflamación de las mezclas B10 fueron determinados de acuerdo a las normas ASTM D-445 y ASTM D-93. La aplicación de los nano-aditivos a las mezclas de biodiesel mostraron un incremento en la viscosidad cinemática desde 2.75 cSt hasta 3.33 cSt a 40°C con una concentración de 20 ppm de nanopartículas en la mezcla B10, mientras que el punto de inflamación incrementó desde 65 °C hasta 66 °C. Estos resultados pueden representar ...

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Low temperature synthesis of ultrafine α-Al2O3 powder by a simple aqueous sol–gel process

Cited by 221 publications

References 11 publications

Densification of Ca-doped alumina nanopowders prepared by a new sol–gel route with seeding

Densification of Ca-doped alumina nanopowders prepared by a new sol–gel route with seeding

Taguchi Optimization for Combustion Synthesis of Aluminum Oxide Nano‐particles

Evaluation of colloidal stability, kinematic viscosity and flash point of B10 Diesel/Biodiesel blends using nanostructured additives based on Al2O3 and oleic acid

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