L1 /
4
CH1012
LYOPHOBIC COLLOIDS
I
1. Lyophobic (in H2O
hydrophobic)
• lyophobic means
‘solvent hating’
• 2 phase colloidal
system (eg.
mud)
• particles are aggregates of small molecules or ions which are insoluble
in the medium.
• do not form spontaneously – special techniques needed,
are not thermodynamically stable w.r.t. separation into 2 separate phases
are not thermodynamically stable w.r.t. separation into 2 separate phases
(although
the reverse kinetics may be slow)
eg. As2O3 dilute+ 3H2S ® As2S3 ¯ colloid + 3H2O