Porous, membrane-like structures with different supramolecular organisation are prepared from solutions of syndiotactic polystyrene in cyclohexanol. Liquid-liquid (L-L) demixing leads to the formation of amorphous materials. They transform into the helix or gamma-phase on heating above T-g. Further heating leads to a melting-recrystallisation process that transforms the gamma-phase into the zigzag or beta-phase. This structure formation prevents re-dissolution of the polymer and maintains the demixed state at temperatures far above the Theta-temperature of the polymer-solvent system. Elimination of the solvent at different temperatures leads to amorphous porous materials or porous materials with the polymer in the gamma- or beta-phase.