1. §8.6 Classification of dispersion system

2. 1. Dispersion system:
One or several substances disperse in another substance serving as medium.
Continuous phase: dispersion medium
Domain: dispersed phase

3. 1.2 Classification of dispersion systems
According to the size of dispersed phase
r / m
Atom number
name
Phase number
uniformity
< 10-9
< 103
Molecular dispersion
Single phase
uniform
10-7~10-9
103~109
Colloidal dispersion
multiphase
10-7~10-4
> 109
Coarse dispersion
nonuniform
Discuss the energy of highly dispersed system (of nano-scale): colloidal system !

4. You can find examples for all these types on our course website!
1.2 Classification of dispersion system according to state
Dispersion medium
Dispersed phase
name
Examples
Gas
liquid
Liquid aerosol
Fog, liquid sprays
Solid
Solid aerosol
Smoke, dust
foam
Whipped cream
Liquid
Emulsion
Milk
solid
sol
paint, mud
gas
solid foam
expanded PS
gel
jellies, opal
Solid suspension
colored glass, smoky crystal
You can find examples for all these types on our course website!

5. You can find examples for dispersion systems on our course website!

6. The colloidal particles interact strongly with the dispersion medium.
1.2 Classification of colloids
--- according to dispersion state
Lyophilic sols:
The colloidal particles interact strongly with the dispersion medium.
Solution of macromolecules (not “true” solution?)
Lyophobic sols:
The colloidal particles and the dispersion medium has no tendency to interact.
Fe(OH)3 sol

7. Semi-permeable membrane
1.3 What is colloids?
1862, Graham:
samples
Diffusion
Semi-permeable membrane
Crystalloids
salt, sugar
rapid
Permeable
Colloids
protein, Fe(OH)3
slow
Non-permeable
Fundamental concepts
Colloids, sol, gel, peptization, dialysis.

8. 1908, Weimarn: Ba(CNS)2 + MgSO4:
sol
gel
precipitation
concentration
diameter
1907, BanmapH
1908, Weimarn: Ba(CNS)2 + MgSO4:
10-4 ~ 10-5 mol dm-3, sol;
10-2 ~ 10-1 mol dm-3, precipitation, crystalline solid
2~3 mol dm-3, gel