Perfluoropolyether/poly(ethylene glycol) triblock copolymers with controllable self-assembly behaviour for highly efficient anti-bacterial materials

Abstract

A series of perfluoropolyether/poly(ethylene glycol) (PFPE/PEG) triblock copolymers PEG/PFPE/PEG (P1–P3) and PFPE/PEG/PFPE (P4–P5) were prepared via thiol–ene click reaction in high yields. Their chemical structures, molecular weights and thermal stability were characterized by ¹H nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA), respectively. The spin coated polymer films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and a contact angle goniometer. The polymer P1–P4 showed a wrinkle-like surface morphology in the film state, but P5 exhibited a segregated morphology due to its poor solubility in the casting solvent. Polymers P1–P4 in thin film states displayed high hydrophilicity with water contact angles in the range of 10.2–12.3° and surface energy of 52.7–55.2 mN m⁻¹ even though hydrophobic PFPE segments were present in the polymer backbone. The anti-bacterial properties of the spin-coated films (P1–P3) were tested against E. coli and S. aureus on a Si surface and remarkable anti-bacterial properties were observed for this series of polymers, particularly for P3 which almost completely prohibits the growth of E. coli and S. aureus, rendering this type of PEG/PFPE/PEG triblock polymer as high performance antimicrobial coating materials.