The viscosity of “liquid-like” and “crystal-like” suspensions of deionized colloidal spheres
The viscosity of “liquid-like” and “crystal-like” suspensions of deionized colloidal spheres
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去离子胶体球的“液体状”和“晶体状”悬浮液的粘度
DOI：
10.1007/bf00368412
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
T. Okubo
中科院分区：
文献类型：
--
作者：
T. Okubo
最近，人们报道了去离子胶体悬浮液的各种特殊性质。典型的例子是形成“晶体状”有序结构[1]，并在X射线和中子散射的小角度曲线上出现一个宽峰，表明悬浮液的“液状”性质[2]。当胶体球被共存的离子交换树脂尽可能完全地去离一周以上时，所产生的悬浮液含有非常少量的离子物种，即来自胶体球解离基团的反离子和从水分子解离的离子。有效离子强度低至10-7M量级。在这种去电离状态下，微球周围的德拜屏蔽长度高度扩展到微米长，静电斥力占主导地位，尽管静电斥力会变得很弱。在这种通信中，测量了完全(离子浓度低至10-7M数量级)去离子悬浮液的胶体二氧化硅和聚苯乙烯乳胶球的粘度。~lSP/c与c(~/sp比粘度，c浓度[g/卷])的关系曲线表现出非常特殊的浓度依赖性，粘度下降。
Quite recently various extraordinary properties of deionized colloidal suspensions have been reported. Typical examples are the formation of a" crystal-like" ordered structure [1], and appearance of a single broad peak in the small-angle curves of X-ray and neutron scattering indicating the" liquid-like" nature of the suspensions [2]. When colloidal spheres are deionized as completely as possible by coexisting ion-exchange resins for more than a week, the resulting suspension contains very small amounts of ionic species, ie, counterions from the dissociate groups of colloidal spheres and ions dissociated from water molecules. The effective ionic strength is as low as the order of 10-7 M. In this deionized state, the Debye-screening lengths around the spheres are highly expanded as long as micrometers and the electrostatic repulsive forces prevail for a long distance, though the forces would become very weak.In this communication, viscosities of colloidal silica and polystyrene latex spheres were measured for completely (ionic concentration as low as the order of 10-7 M) deionized suspensions. The plots of~ lsp/c against c (~/sp specific viscosity, c concentration [g/roll) showed very extraordinary concentration dependence and the viscosity de-