Study On Kerosene Gelation Using Nanometer Silica Or Cellulose Deriative As Gelator

Conventional propellants mainly include liquid propellants and solid propellants.Liquid propellants are mostly flammable,explosive,and thus the maintenance and use safety are poor.However,they have higher impulse performance,the adjustable thrust,can be ignited and started for many times,and the thrust is easy to control.Solid propellants have high maintenance and use safety,but in general,their energetic characteristics and impulse performance are unsatisfactory,multiple restart is difficult and the thrust controllability is poor.To solve the above shortcomings,in recent years,some countries have sequentially turned their research interests to the gel propellants those have the advantages of both liquid and solid propellants.As a new generation of liquid propellant fuel,the aviation kerosene is promising in future.In this study,with either nano-SiO₂ or cellulose derivative as the gelator,the formula and preparation conditions of the kerosene gel have been studied based on common kerosene instead of aviation kerosene.The rheological properties of the gels have been evaluated.First,the effects of surface hydrophobicity,particle size,stirring rate,surfactant and polar solvent on the formation of SiO₂/kerosene gel were investigated.The rheological properties of the gels were measured by a rotary rheometer.It was found that the gel could be formed when the loading amount of hydrophilic SiO₂ was5%-8%.Within a certain range,higher agitation rate and smaller particle size will help to shorten the gelation time.Polyoxyethylene octylphenol ether-10?OP-10?and ethanol are not conducive to the gelation.When the loading amount of hydrophobic SiO₂ is4%-6%,the kerosene turned into the gel,however it had no thixotropy.With the addition of 5%-7%hydrophilic SiO₂,the kerosene gel exhibited pseudoplasticy under high-speed shear,and the rheological performance conformed to H-B equation.With the increase in the amount of the gelator,both K and?_yield value increased.The sample S30-1 and S30-3 exhibited good shear thixotropy.With the shear rate increased,the viscosity of the gel decreased rapidly.After the removal of the shear force,the structural recovery rate reached 68.7%and 81.3%,respectively.Second,the kerosene was gelated using cellulose derivative such as carboxymethylcellulose?CMC?,hydroxypropylcellulose?HPC?,hydroxyethylcellulose?HEC?or methylcellulose?MC?as the gelator.The effects of the concentration and dosage of the aqueous solution of the gelator,the type and amount of the surfactant and polar solvent,and the temperature on the gelation properties of the kerosene were studied.The shear thixotropy and dynamic viscoelasticity of the gels were characterized.The results show that several kinds of cellulose derivatives studied can make the kerosene form the gel.The temperature and the dosage of the gelator had great influences on the gelation time of HEC/kerosene system,and it took only 0.5h to form the gel at 30?.As the loading amount of HEC increased,the gel time was shortened.CMC/kerosene,HEC/kerosene,HPC/kerosene gel systems showed pseudoplasticy and the viscosity decreased rapidly under high-speed shear,and the gel could be reformed once the shear force was withdrawn.The viscoelastic region of the three gel systems falled in the range of 0.1%-1.5%of the strain and the loss coefficient tan?was less than 1,proving that the elastic behavior was more obvious than the internal friction.