纳米材料改性沥青的制备及分散稳定机理

采用纳米CaCO3、纳米ZnO和纳米TiO2复配纳米材料对SBS沥青进行改性，并优化了制备工艺条件；研究了表面活性剂纳米材料在SBS沥青中的改性机理。结果表明：纳米CaCO3、纳米ZnO和纳米TiO2质量分数比为1∶2∶1、总添加质量分数为4%时，对SBS沥青的改性效果和经济性最好；在反应温度170~180 ℃、反应时间40 min、最高剪切速率为7000 r/min、剪切次数为2次时，制备的纳米改性沥青的综合性能最优。纳米材料提高了沥青的热稳定性，增强了沥青的抗老化性能；非离子表面活性剂在纳米粒子表面形成反胶束，改变了纳米粒子表面性质，使得纳米材料在沥青中可以均匀分散和稳定存在。

Preparation of Nano-Materials Modified Asphalt and the Dispersion Stabilization Mechanism

SBS asphalt was modified by nano-CaCO3, ZnO and TiO2, and the preparation conditions were optimized. The mechanism of surfactant-modified nano-materials in SBS asphalt was studied. The results show that when the mass fraction ratio of nano-CaCO3, ZnO and TiO2 is 1∶2∶1 and the addition mass fraction is 4%, the modification effect of SBS asphalt and the economy are the best. Furthermore, it is found that when the reaction temperature is 170-180 ℃, the reaction time is 40 min, the highest shear rate is 7000 r/min, and the shear times is two, the performance of nano-modified asphalt is the best. The above-mentioned results demonstrate that nano-materials could improve the thermal stability of asphalt and enhance the aging property of asphal. Lastly, the mechanistic studies reveal that nonionic surfactants form reverse micelles on the surface of nano particles, which change the surface properties of nano particles. As a result, nano-materials can be dispersed and stabilized in the asphalt.