不同分散条件和pH值对TiO_2悬浊液性能影响研究

TiO2悬浊液的稳定性对于光催化应用而言是非常重要的。对于不同粒径的纳米TiO2颗粒在超声分散和搅拌分散、不同pH条件下的团聚和沉降进行了考察,结果显示颗粒的团聚和沉降与分散形式、颗粒粒径、pH值密切相关。颗粒采用超声分散的稳定性较好,但仍会发生沉降,而颗粒粒径越大,团聚和沉降越明显;pH值的影响与距离等电点远近有关系,越近则越容易团聚和沉降,但酸性条件下的分散性要好于碱性条件。结合相关理论,对于其中的机理也进行了探讨。

Influence of Different Dispersion Conditions and pH on Stability of TiO2 Suspension

The stability of TiO2 suspension is very important for photocatalysis. The aggregation and settlement of TiO2 with different particle diameters was studied under ultrasonic and agitating dispersion, various pH, the result showed that the aggrega- tion and settling of particles were related to dispersion conditions, particle size and pH. The stability was better under ultrasonic dispersing although the settlement of suspension finally happened, and the aggregation and settlement were more obvious with the increase of diameter. The influence of pH is related to the distance to isoelectrie point, in which the non - stability was more re- markable with deceasing the distance, the dispersing under acid condition was better than under alkaleseeney. Based on related theory, the mechanism was also discussed .