SiO2凝胶干水粉体性能研究

Study on Properties of SiO 2 Gel Dry Water Powders

本研究在高速剪切搅拌的条件下制备了以SiO2水凝胶为芯材、纳米疏水SiO2为壁材的凝胶干水粉体,测定了粉体的流动性、稳定性、粒度分布、松密度、斥水性等性质参数并进行了对比分析。与普通干水粉体相比,SiO 2凝胶干水粉体的休止角小、流出速度较大,具有更好的流动性。干水粉体在2000 r/min离心转速下就会被破坏,而凝胶干水粉体在离心转速达到6000 r/min时才会出现结块现象。凝胶干水粉体的松密度比干水粉体小。由于采用了疏水性SiO 2作为壁材,该粉体具有较好的斥水性。

In this paper,a gel dry water was prepared using SiO 2 gel as the core and hydrophobic nano SiO2 particle as the shell under high-speed shear.Powder parameters like fluidity,stability,particle size distribution,bulk density and water repellency were studied.The results show that compared with the traditional dry water powder,SiO 2 gel dry water powder shows smaller repose angle,larger outflow velocity and better fluidity.The traditional dry water powder can be destroyed at the centrifuge speed of 2000 r/min,while SiO 2 gel dry water powder only agglo-merate when the centrifuge speed reaches 6000 r/min.The bulk density of SiO2 gel dry water powder is smaller than dry water powder.For the existence of hydrophobic nano SiO2 shell,the as-prepared SiO 2 gel dry water powder presents excellent water repellency.