| Aluminum nanoparticles(Al NPs)are valuable for many energy related applications because of it’s low atomic number,low density,high abundance,low cost and the high heat of reaction to form aluminum oxide(?Hr=31 kJ/g)via reaction with water and oxygen,processes which involve the evolution of a large amount of hydrogen gas and heat.But the presence of surface oxide layer hinders its applications.How to synthesis the particles with uniform morphology and avoid generating the oxide on the surface,enhance the mass fraction of active aluminum elemental is particularly important.In this paper we focus on two kinds of chemical synthesis methods of Al NPs,they are redox reaction and decomposition of precursor.Also we explore the diameter tendency of Al NPs with the changes of experimental conditions and dispersion into the hydrocarbon fuels.The preparation of the Al NPs is based on Haber method with the presence of the organic solvent and organic capping agent.The Al NPs will be capped as soon as it generated.It demonstrates that when oleyl amine is regarded as capped agent,the diameter of Al NPs prepared with Toluene as solvent is less than Al NPs prepared with 1,3,5-Trimethylbenzene as solvent.When the capping agent is changed from oleyl amine to oleic acid,the morphology of Al NPs is nanowires under mechanical stirring.With the increase of reaction time,the morphology of Al NPs can be transformed from nanowires to plate.In order to synthesis the particles with much smaller diameter,we attempted that the Al NPs prepared from the titanium-catalyzed thermal decomposition of a precursor solution.We explored Al NPs capped with oleyl amine,1,2-epoxyhexane,trioctylphosphine oxide and oleic acid.Those Al NPs have different particle diameter distribution.In the consideration of TGA and TEM,oleic acid is selected as the capping agent.Al NPs capped with oleic acid can be stable and have no oxidation when it is exposed in air at least seven months.with the increase of the ratio of oleic acid,the geometric mean diameters of the Al NPs capped with oleic acid decrease first and then increase.The minimum geometric mean diameter size of 16 nm are prepared by capped with oleic acid agents at the optimal synthetic conditions.This work infers that Al NPs maybe have special chemical bonds with capping agents.Al NPs which prepared from the titanium-catalyzed thermal decomposition of a precursor were dispersed in fuel JP-10.In the case of dispersant,we respectively used the ultrasonic treatment and magnetic stirring for the dispersion.With the increase of the amount of dispersant and ultrasonic time,the absorbance of suspension become larger,the stability can be improved and the diameter of nanoparticles in JP-10 is decreased. |
