Surface-induced layer formation in polyelectrolytes
  We analyze, by means of an RPA calculation, the conditions under which a mixture of oppositely charged polyelectrolytes can micro-segregate in the neighborhood of a charged surface creating a layered structure. A number of stable layers can be formed if the surface is sufficiently strongly charged even at temperatures at which the bulk of the mixture is homogeneous. 
F. J. Solis and M. Olvera de la Cruz