Patterning in rapidly evaporated polymer solutions: formation of annular structures under evaporation of the poor solvent

Patterning in the intensively evaporated polymer solutions based on polystyrene and poor solvent (acetone) was investigated. SEM and AFM studies demonstrated that annular elements of the surface topography are formed in this case, in contrast to the honeycomb patterns obtained under the evaporation of the good solvent (chloroform). The authors suggest that the theory of viscous dewetting developed by de Gennes explains the phenomenon satisfactorily.