8.8.1 Electrokinetic phenomenon of colloid (I)Electropho the motion of colloidal particles under the action of an electric field sands (2) Electro-osmosis the motion of dispersion medium The experiments done by PeNce in 1809 under electric field demonstrated that both colloidal particles and dispersion medium are charged and can move under electric fields The colloidal particles of clay is negatively charged A colloidal particle may has hundreds of chargeThe experiments done by PeNcc in 1809 demonstrated that both colloidal particles and dispersion medium are charged and can move under electric fields. The colloidal particles of clay is negatively charged. A colloidal particle may has hundreds of charge. 8.8.1 Electrokinetic phenomenon of colloids (1) Electrophoresis: the motion of colloidal particles under the action of an electric field. (2) Electro-osmosis: the motion of dispersion medium under electric field