Self-assembled colloid and solvent-responsive property of amphiphilic fluoropolymer for protein-resistance coatings

Amphiphilic fluorocopolymer P (PEGMA)-co-P (DFHM) is prepared by hydrophobic dodecafluorohrptyl methacrylate (DFHM) and hydrophilic poly (ethylene glycol) methyl ether methacrylate (PEGMA) monomers via atom transfer radical polymerization (ATRP). The self-assembled colloids of P (PEGMA)-co-P (DFHM) in ethanol, dimethylformamide (DMF), tetrahydrofuran (THF), and chloroform (CHCl₃) solutions are discussed according to solvent dielectric constants (ε = 38.3–4.8). The hydrophilic/hydrophobic property, protein resistance, and adhesive strength of films formed by these colloids are evaluated based on the surface morphologies and chemical compositions. P (PEGMA)-co-P (DFHM) can self-assembly into core-shell micelles composed of P (PEGMA) shell and P (DFHM) core (~130 nm) as 500–600 nm in DMF, 300–400 nm in ethanol, and 200–250 nm in THF and CHCl₃ solutions. These colloids provide the film surfaces with high fluorine content (39.40–41.70 wt%) to indicate the migration of fluorine-containing groups onto the film surface during the film formation and therefore the obvious hydrophilic/hydrophobic properties (94.3°–102.4° water contact angles and 58.5°–60.2° cetane contact angles). Comparatively, DMF-casted film gains the highest surface roughness (Ra = 0.98 nm), the lowest fluorine content (39.40 wt%), and the highest surface free energy (20.41 mN m⁻¹) due to its large size of colloids, but CHCl₃-casted film gives the lowest surface free energy (17.82 mN m⁻¹). The adhesive strength for DMF- and ethanol-casted films (210 and 168 N) proves higher than THF- and CHCl₃-casted films (105 and 63 N), while DMF-casted film shows much better protein resistance (Δf = −15.0 Hz) than other three films (Δf = −17–20 Hz). It is believed that the obtained P (P EGMA)-co-P(DFHM) could have a promising application as solvent-dependent and protein-resistance coatings.