Investigations of variations in surface state of polymer films under structural rearrangements in air and during contact with water

Abstract

Films of methyl methacrylate–styrene copolymers with the different composition ratios were synthesized; the relaxation processes in a surface film layer were studied when it was in an air environment and during a long-term contact with an aqueous phase. It was shown by analyzing the contact angle and the surface tension of a droplet that the surface structural rearrangement in air after the film deposition was a timeconsuming process developing over tens of days. At the same time, the surface chains in contact with the aqueous phase reoriented in tens of hours. These structural variations observed owing to contact with the aqueous phase were reversible and could be remedied by a subsequent drying in air.