Abstract
Electrophoretic mobilities of allophane-imogolite mixtures in different proportions were determined at a fixed pH of 10.8-10.9. The absolute value of electrophoretic mobility of allophane significantly decreased by the addition of a small amount of imogolite. In a 30 % imogolite and 70% allophane mixture, allophane was flocculated perfectly with imogolite, and showed zero electrophoretic mobility. Flocculation of allophane with imogolite was also observed when alkali-dispersed allophane was mixed with imogolite which had been flocculated at pH 10.8. The flocculation of allophane with imogolite under a strong alkaline condition may be due to immobilization of allophane by newly-formed network of imogolite particles.
