Bruinsma PJ, Wang Y, Li XS, Liu J, Smith PA, Bunker BC
Materials Sciences Department, Pacific Northwest National Laboratory2, Batelle Boulevard, Richland, Washington, 99352
J Colloid Interface Sci. 1997 Aug 1;192(1):16-25. doi: 10.1006/jcis.1997.5013.
Bimodal suspensions of nanometer-sized boehmite particles and micron-sized gibbsite particles in 0.10 M NaNO3 are used as models to gain insight into the physical properties of agglomerating colloidal suspensions containing bimodal distributions of primary particles. Results on the gibbsite-boehmite mixtures show that the presences of small particles in a suspension can have a dramatic impact on the rheological, sedimentation, and filtration characteristics of suspensions of larger particles. Transmission electron micrographs show that boehmite forms a coating on the larger gibbsite particles. The coating provides steric repulsion and reduces the attractive interactions between the larger particles, leading to viscosity decreases and greater densification of sediments and filter cakes. A model has been developed to rationalize observed property changes based on the range of agglomerate structures that can form in mixtures of large and small particles. Results are discussed in the content of the processing of nuclear waste sludges, but are applicable to a wide range of bimodal suspensions.
在0.10 M硝酸钠中，纳米级勃姆石颗粒和微米级三水铝石颗粒的双峰悬浮液被用作模型，以深入了解含有初级颗粒双峰分布的团聚胶体悬浮液的物理性质。三水铝石-勃姆石混合物的结果表明，悬浮液中小颗粒的存在会对大颗粒悬浮液的流变学、沉降和过滤特性产生显著影响。透射电子显微镜照片显示，勃姆石在较大的三水铝石颗粒上形成涂层。该涂层提供空间排斥作用，减少较大颗粒之间的吸引相互作用，导致粘度降低，沉积物和滤饼的致密化程度更高。基于大小颗粒混合物中可能形成的团聚体结构范围，已经开发了一个模型来合理化观察到的性质变化。结果在核废料污泥处理的背景下进行了讨论，但适用于广泛的双峰悬浮液。
