Page 236 - Introduction to Colloid and Surface Chemistry
P. 236

Colloid stability  225
































         Figure  8.5  Distribution  and  density  of  dispersion  medium  molecules  between
         molecuiarly smooth solid surfaces




         the  principles  developed  in  this  chapter  for  particle-particle  inter-
         actions  apply  also  to  particle-solid  substrate  interactions.  Many
         indirect  methods  involving centrifugation,  vibration,  etc., have  been
         developed  to  measure the  force required  to  detach  particles from  a
         solid  surface.


         Determination and prediction of critical coagulation
         concentrations


         The  transition  between  stability  and  coagulation,  although  in
         principle a gradual one,  usually occurs  over a reasonably  small range
         of  electrolyte concentration,  and  critical coagulation  concentrations
         can  be  determined  quite  sharply.  The  exact  value"  of  the  critical
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