The kation effect (small) is Na > K > NH4 > Mg
Other lyotrope substances raise or lower the temperature thus:—
glucose > glycerol—(H2O)—alcohol < urea
The effect on gelation is also illustrated by the change of viscosity of the sol with time. The same lyotrope order is found.
In the salting out or precipitating of gelatine with salts, the order of anions is lyotrope:
SO4 > citrate > tartrate > acetate > Cl
Also the osmotic pressure of gelatine sols is markedly lowered by neutral electrolytes in lyotrope sequence:
Cl > SO4 > NO3 > Br > I > CNS
Similarly lyotrope influences are shown in the modulus of elasticity: substances which favour gelation increase elasticity, whilst substances which favour solation decrease elasticity. The order is again lyotrope.
The permeability of the gel is affected by lyotrope influences; alcohol and glycerol reduce diffusion through gelatine (or agar); and urea, chloride and iodide increase it. (Similarly the diffusion of sols through "semipermeable" membranes is affected by lyotrope influence.) The lyotrope series also influence the optical activity of gelatine sols and the double refraction of strained gels.