Abstract

Fluoropolymer films were deposited on pristine and N₂ plasma-pretreated copper foil surfaces by plasma polymerization of allylpentafluorobenzene (APFB) under different glow discharge conditions and using argon as the carrier gas. The effect of the radio-frequency (RF) plasma power on the surface composition and chemical structure of the plasma-polymerized APFB (pp-APFB) films was studied by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS) and water contact angle measurements. The XPS, ToF-SIMS and FTIR results suggested that the fluorinated aromatic structure in the deposited polymer films had been preserved to various extents, depending on the input RF power used for the plasma polymerization. The roughness of the APFB plasma-polymerized copper (pp-APFB-Cu) surface increased substantially with the RF power, as revealed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Ultra-hydrophobic pp-APFB-Cu surfaces with water contact angles greater than 140° were obtained at RF powers above 50 W. The solvent extraction and the Scotch^® tape peel test results revealed that the pp-APFB layers were strongly bonded to the N₂ plasma-pretreated copper surfaces.