Hydrophobic and superhydrophobic surfaces fabricated by plasma polymerization of perfluorohexane, perfluoro(2-methylpent-2-ene), and perfluoro(4-methylpent-2-ene)

Fluoropolymer films were deposited on silicon (100) wafers, glass, epoxy, and hierarchical dual-sized filler epoxy composite surfaces by plasma polymerization of perfluorohexane, perfluoro(2-methylpent-2-ene), and perfluoro(4-methylpent-2-ene). The procedure involved continuous wave plasma-enhanced deposition, followed by a discharge-off period, with the monomer gas feed maintained. Silanization of silicon wafers and glass surfaces with triethoxyvinylsilane was employed to improve plasma fluoropolymer bonding to these substrates. The presence of double bonds in perfluoro(2-methylpent-2-ene) and perfluoro(4-methylpent-2-ene) was found to influence fluoropolymer coating topography, thereby increasing surface roughness in modified glass and epoxy substrates. All fluorocarbons provided a similar level of hydrophobization of flat substrates, exhibited by water contact angles (WCA) of about 110 degrees. Hydrophobization of nanocomposite hierarchical surfaces by plasma polymerization provided superhydrophobic surfaces, with WCA of 160 degrees and contact angle hysteresis below 8 degrees.