92168.pdf

The colloidal state 19

Motor

Colloidal solution

being dialysed

Visking dialysis

tubing

Figure 1.5 A simple dialysis set-up

index of the emerging solution, and the relationship between

retention time and relative molecular mass is determined by

calibrating the apparatus with polymer fractions which have been

characterised by other methods, such as osmotic pressure (see page

37), light scattering (see page 57) or viscosity (see page 251).

A further modification of dialysis is the technique of electrodialysis,

as illustrated in Figure 1.6, The applied potential between the metal

_J

—

— Solvent -

i

•4 —

W i

==•===•"=£1= =

5 -solution ErH^1

r ^T'_: _r-z_'"ZJ'nz; zi ;

r :

L

r~i — -

\

• —f—
  F"^1 "^1 "' — —.. r-__jL.,
  1— Solvent —
  1
  1
  1

J*=-

r

Figure 1.6 Electrodialysis