Methacrylic polymers containing aromatic groups at the water—air interface

Abstract

Listen

Translate article

Monolayers of polymethacrylates containing either aromatic or linear side groups were studied at the air—water interface. The aims of the work were as follows: (1) to define the role of the aromatic group in determining the interfacial distribution and orientation of these polymers and (2) to define the extent to which geometrical orientation and aromatic interactions affected surface compatibility in ordered two-dimensional systems. Surface pressure and surface potential measurements were performed in the 288–303 K temperature range on both the pure components and their mixtures. Further information was obtained from ellipsometric measurements of polymers that can easily be transferred from liquid to solid supports and from scanning electron microscopy of the collapsed materials. The experimental results showed that all the polymers give stable expanded monomolecular films and suggested that both aromatic and aliphatic polymers are in an almost horizontal conformation at the liquid—air interface. A comparison of the experimental isotherms with Huggins' theory showed that no preferential interactions existed between the benzene rings in the film. In contrast, preferential attractive energies were observed for n-alkylmethacrylates. A study of the two-dimensional mixtures led to the conclusion that both polymers containing aromatic groups were almost ideally miscible, whereas mixtures of aliphatic and aromatic polymers were completely immiscible.