8.8.2 Dynamic properties of colloids (3 )Sedimentation and sedimentation equilibrium Mean concentration:(c-12 dc D)sedimentation equilibrium The number of colloidal particles diffusion Buoyant (c-)AchL 2 Di Diffusion force 丌=CRT Gravitational dn= rTdc orce b h The diffusion force exerting on each colloidal particle rTdc dc c-)AdhL cdhL(3) Sedimentation and sedimentation equilibrium diffusion 1) sedimentation equilibrium Gravitational force Buoyant force a a’ b b’ c dh Mean concentration: (c - ½ dc) The number of colloidal particles: AdhL dc c ) 2 ( − Diffusion force:  = cRT d = RTdc The diffusion force exerting on each colloidal particle cdhL RTdc AdhL dc c Ad f d = − = ) 2 (  8.8.2 Dynamic properties of colloids