CH1012
                                         L1 /   
‹#›
                                         L1 /   
2
hepa-diagram
>0.3mm

HEPA
 Filter
COLLOIDS
Dispersed System
• any homogeneous medium
(dispersion medium) containing
dispersed particles (disperse phase).
 Ostwald (1900):  World of Neglected Dimensions
Colloids
Coarse Disp. Colloid      Molecular Disp.
> 1 mm              1 mm - 10 nm           < 10 nm
std. filters ultrafilters not retained
optical electron scanning tunneling
microscope   micro.             micro.
IBM IBM IBM
Xe atoms
  5 nm tall