A medium comprises an electrolyte wherein is dissolved at least an assembly
of block copolymers characterized in that the block copolymers: are
present in the electrolyte at a concentration level to provide the medium
with the property of reversibly passing from a state of viscosity V1,
obtained at a temperature T1, to a viscosity state V2 greater by at least
100% than V1, obtained at a temperature T2, and comprise in their
structure at least: two non-contiguous polymeric segments having in the
electrolyte a lower critical solubility temperature (LCST) and having an
average number of atoms along their skeleton more than 50; and a polymeric
segment soluble in the electrolyte at temperatures T1 and T2. The
invention also concerns the use of the medium for separating analytes.
