Novel Synthetic Approach to Tune the Surface Properties of Polymeric Films: Ionic Exchange Reaction between Sulfonated Polyarylethersulfones and Ionic Liquids

ABSTRACT

Currently, no studies dealing with the role played by ionic liquids on tailoring surface features of polymer films are available. In this work, ionic liquids influence on the surface of sulfonated polyarylethersulfones was investigated. Sulfonated polyarylethersulfones with different degrees of sulfonation were synthesized; their surface properties were modulated through an ionic exchange reaction between the K⁺ cation of sulfonated polyarylethersulfones and ionic liquids, synthesized changing the length of cation of apolar groups. Hydrophobic properties of sulfonated polyarylethersulfones–ionic liquids films improve with both an increase in degrees of sulfonation and the length of ionic liquids alkyl chains due to higher surface roughness, as shown by scanning electron microscopy and atomic force microscopy.

GRAPHICAL ABSTRACT

KEYWORDS:

• Cation-exchange reaction
• hydrophobic film
• ionic liquid
• sulfonated polyarylethersulfone
• surface roughness

Acknowledgments

The authors wish to express their gratitude to Professor Giuseppe Di Silvestro (CRC Materiali Polimerici (LaMPo), Dipartimento di Chimica, Università degli Studi di Milano) for stimulating discussion and scientific projects. V.S. wish to express her gratitude to both Dr. Stefano Malacrida and Dr. Mirko Zappa for their experimental contributes.