Raşa M, Philipse A P, Meeldijk J D
Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
J Colloid Interface Sci. 2004 Oct 1;278(1):115-25. doi: 10.1016/j.jcis.2004.05.020.
We report a study of mixtures of initially oppositely charged particles with similar size. Dispersions of silica spheres (negatively charged) and alumina-coated silica spheres (positively charged) at low ionic strength, mixed at various volume ratios, exhibited a surprising stability up to compositions of 50% negative colloids as well as spontaneous repeptization of particles from the early-stage formed aggregates. The other mixtures were found to contain large heteroaggregates, which were imaged using cryogenic electron microscopy. Electrophoretic mobility, electrical conductivity, static and dynamic light scattering and sedimentation were studied as a function of volume fraction of the mixed dispersions to investigate particle interactions and elucidate the repeptization phenomenon.
我们报告了一项关于初始带相反电荷且尺寸相似的粒子混合物的研究。在低离子强度下，将二氧化硅球（带负电荷）和氧化铝包覆的二氧化硅球（带正电荷）以不同体积比混合形成的分散体，在负性胶体组成高达50%时表现出惊人的稳定性，并且早期形成的聚集体中的粒子会自发再分散。发现其他混合物含有大的异质聚集体，使用低温电子显微镜对其进行了成像。研究了电泳迁移率、电导率、静态和动态光散射以及沉降与混合分散体体积分数的关系，以研究粒子间的相互作用并阐明再分散现象。
