High-Density Suspension Fuels Containing Oil-dispersable Nanoparticles

Liquid hydrocarbon fuels are crucial to provide power for a variety of aerospace engines, thus occupying an important position in the field of propellant. Fuel performance(especially energy and density) is one of the key determining factors of flight performance(including flight range, flpeed and payload, etc.). Development of new high-performance aircraft requires higher energy of propulsion fuel. Up to now, impressive progress has been made in high-energy liquid fuel by chemical synthesis. But it is difficult to further increase the energy by synthesizing new hydrocarbon molecules because the melting point and viscosity rise quickly with the increase of density. Therefore, new approach is necessary to prepare liquid fuel with higher density and volumetric energy.In this thesis, oil-soluble high-energy nanoparticles including boron, carbon, aluminum nanoparticles were synthesized and dispersed in high-density liquid fuels to form a new type of suspension fuel. The surface-modified nanoparticles were characterized by various methods, as well as the performance of the new fuels were tested, confirming the feasibility of this new approach to enhance the fuel density and volumetric energy.In order to make high-energy nanoparticles compatible with liquid hydrocarbon fuel, a simple, gentle, efficient method of reflux or ultrasonic dispersion was established to modify the surface of boron, carbon tubes and aluminum nanoparticles, using a variety of protective agents. It is found that tri-n-octyl phosphine oxide, oleylamine and oleic acid are the best reagents for boron, carbon tubes and aluminum nanoparticles, respectively. Then, oil-soluble nanoparticles were dispersed in high density fuel inlcuding HD-03 and HD-01 to form suspension fuel. About 15 wt% of nanoparticles could stably dispersed in the liquid fuel after six weeks.Further, the density, viscosity, fluidity, heat values of two suspension fuels(HD-01 and HD-03) containing 10 wt%, 20 wt%, 30 wt% of high-energy particle were tested and calculated. The density and volumetric energy of the suspension fuels are increased gradually with the rise of nanoparticles. When 30 wt% nanoparticles were added, the highest density could be up to 1.23 g/m L(Al/HD-03), and the highest volumetric heating value could be up to 58.1 MJ/L(B/HD-03), that is higher than RJ-5 fuel which possesses the highest of density and volumetric energy currently. At room temperature, the suspension fuels could flow like pure liquid fuel, and indicative of good low temperature viscosity. The addition of boron, carbon tubes and aluminum nanoparticles can also shorten the innition decay of quardricyclan/fuming nitric acid and quardricyclan/N2O4, and boron nanoparticles show the best effect. In the engine ignition experiments, nanoparticles dispersed in suspension fuel could combust completely, and no pipeline jam phenomenon occurred.