纳米二氧化硅乳化沥青的制备与Pickering乳化机理分析

为了提高乳化沥青的路用性能,实现乳化剂与改性剂的统一,在分析Pickering乳化机理与传统乳化沥青乳化机理的基础上,制备了性质良好的新型乳化沥青——纳米SiO_2乳化沥青,并通过微观手段分析了乳液稳定机理,最后按照道路用乳化沥青检测方法对纳米SiO_2乳化沥青进行了检测.结果表明:除蒸发残留物延度有所降低外,纳米SiO_2乳化沥青基本满足道路用乳化沥青技术标准,同时乳液稳定性、蒸发残留物软化点和针入度都得到了改善;在Pickering乳液稳定机理下,用于改性沥青的纳米SiO_2可以直接作为乳化剂.

Preparation of Nano SiO2 Emulsified Asphalt and Pickering Emulsification Mechanism

In order to improve the performance of emulsified asphalt, a particle emulsifier was introduced. It served both as the emulsifier and modifier for asphalt. A new type of emulsified asphalt, the nano silicon dioxide(SiO2) emulsified asphalt, was prepared successfully. The following steps were conducted in the study. First, a comparison was made regarding the emulsification mechanism between the Pickering and traditional emulsification. Then, the stable nano SiO2 emulsified asphalt was prepared. The stability mechanism of the emulsion was examined through a microscopic approach. Finally, the engineering indexes were tested on the nano SiO2 emulsified asphalt. It is revealed that except the slightly reduced ductility, the nano SiO2 emulsified asphalt can meet the Chinese emulsified asphalt specification with improved stability, penetration, and softening point of the residual after evaporation. In summary, this study verifies the feasibility of using the nano SiO2 as asphalt emulsifier based on Pickering emulsion stability.