Stable hydrophobic surfaces created by self-assembly of poly(methyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate units

Poly(methyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate units (PMMA-ec-FMA) have been synthesized by ATRP. Hydrophobic surfaces having contact angles of water and paraffin oil of 120° and 84°, respectively, were prepared using the end-capped PMMA with 0.38 mol% FMA (PMMA857-ec-FMA3.30). However, more than 13.63 mol% FMA was necessary for random copolymer PMMA-r-PFMA to obtain similar values. The end-capped PMMA with such a low FMA content also has better resistance to surface reconstruction than the PMMA-r-PFMA with 13.63 mol% FMA. The surface properties and structures for both polymers were investigated using contact angle measurement, X-ray photoelectron spectroscopy, and X-ray diffraction. It was found that this increased resistance was attributed to the structure of the end-capped polymer, which favors the longer -(CF2)7CF3 moieties self-assembling on the polymer surface during film formation on glass slides, resulting in better chain alignment and packing of the longer -(CF2)7CF3 moieties.