Electrical double layers and colloidal flocculation

Adachi, Yasuhisa*; Kobayashi, Motoyoshi*; Feng, L.*; Tsujimoto, Yoko*; Yamashita, Yuji

The electrical double layer is a well-known concept of a charged surface in an electrolyte solution. In the present article, we go back to the original history of electrokinetics to note how the concept has been established. In the first approximation, we pay attention to one dimensional plate model and discuss on the effectiveness of the DLVO theory in relation to the stability of colloidal dispersion. It is already about seventy years from the proposal of the DLVO theory and its effectiveness has been discussed in many respects. Nevertheless, there still exist unanswered important questions on the flocculation of charged colloids moving with diffusive electrical double layer. In terms of history and progress in technology, an approach using fluid mechanics will be essentially important in future.