Antifouling Properties of Poly(2-Oxazoline)s and Poly(2-Oxazine)s: Direct Comparison of Polymer-Coated Surfaces with the Same Coating Parameters

Abstract

This study presents a systematic comparison of the antifouling properties of water-soluble poly(2-oxazoline) (PAOx) and poly(2-oxazine) (PAOzi) brushes grafted to gold surfaces. PAOx and PAOzi are emerging polymer classes in biomedical sciences and are being considered superior alternatives to widely used polyethylene glycol (PEG). Four different polymers, poly(2-methyl-2-oxazoline) (PMeOx), poly(2-ethyl-2-oxazoline) (PEtOx), poly(2-methyl-2-oxazine) (PMeOzi), and poly(2-ethyl-2-oxazine) (PEtOzi), each of them in three different chain lengths, are synthesized and characterized for their antifouling properties. Results show that all polymer-modified surfaces display better antifouling properties than bare gold surfaces as well as analogous PEG coatings. The antifouling properties increase in the following order: PEtOx < PMeOx ≈ PMeOzi < PEtOzi. The study suggests that the resistance to protein fouling derives from both surface hydrophilicity and the molecular structural flexibility of the polymer brushes. PEtOzi brushes with moderate hydrophilicity show the best antifouling performance, possibly due to their highest chain flexibility. Overall, the research contributes to the understanding of antifouling properties in PAOx and PAOzi polymers, with potential applications in various biomaterials.

Keywords: antifouling coatings; poly(2-oxazine)s; poly(2-oxazoline)s; polymer brushes.