基于流变特性的含铝凝胶燃料制备工艺研究

为提升液固燃料的结构稳定性，以无机纳米颗粒为凝胶剂制备了环氧丙烷基凝胶基质，在基质中引入微米铝粉,得到含铝凝胶燃料。通过测定凝胶基质的弹性模量G′₀和线性区范围γ_c，分析了超声和热处理对纳米颗粒成胶的影响。针对不同含铝量的凝胶燃料，在不同剪切速率（0.1～2 000.0 s^-1）下，进行了旋转剪切测试，并研究了剪切历史对燃料流动曲线的影响。结果表明，超声和加热对纳米颗粒的成胶效果皆有促进作用。低剪切速率（γ<100 s^-1）下，剪切历史会使得凝胶体系黏度增高；超过100 s^-1后，黏度较无剪切历史的样品低。流动曲线显示，含铝凝胶燃料在100 s-1附近出现增稠现象，而更高的剪切速率直接导致凝胶结构在短时间内出现不可逆破坏，致使黏度迅速降低。

Preparation Process of Aluminium-Containing Gel Fuel Based on Rheological Properties

In order to improve the structural stability of liquid-solid fuel, tetrahydrofuran-based gel matrix was prepared using inorganic nanoparticles as gel agent, and aluminum-containing gel fuel was obtained by filling micron aluminum powder into the matrix. The effects of ultrasound and heat treatment on the gelation of nanoparticles were analyzed by measuring the elastic modulus G′₀ and the linear region γc of the gel matrix. Rotating shear tests at different shear rates (0.1-2 000.0 s^-1 ) were carried out for gel fuels with different aluminum contents, and the influence of shear history on the fuel flow curve was studied. The results show that ultrasound and heating can promote the gelling outcome of nanoparticles. Under low shear conditions (γ·<100 s^-1), the shear history will increase the viscosity of the gel system, and after 100 s^-1, the viscosity will be lower than that of the sample without shear history. It shows that the aluminum-containing gel fuel thickens around 100 s^-1?in the flow curves, and the higher shear conditions directly lead to the irreversible destruction of the gel structure in a short time, resulting in a rapid decrease in viscosity.