Surface Characteristics and Electrical Properties of Perfluoroalkane and Perfluorodiacetylene Langmuir-Blodgett Films

Abstract

Surface pressure-area curves for perfluoroalkanes (C₁₆F₃₄, C₂₀F₄₂ and C₂₄F₅₀) and novel perfluorodiacetylene (C₂₄F₄₂) showed monolayers to form on the surface of water. Monolayers of perfluorocompounds were deposited on various substrates by Langmuir-Blodgett (LB). A comparison of reflection-absorption and transmission IR spectra indicated difluoromethylene chains in LB film to be oriented perpendicularly to the substrate. Perfluoroalkane LB film (C₂₀F₄₂ and C₂₄F₅₀) on hydrophobized mica showed excellent water repellency with contact angles of water, 155° and 153°. Perfluorodiacetylene LB film on a KRS-5 plate demonstrated excellent water repellency with a contact angle of 162° and that on a quartz plate, after polymerization by UV irradiation, was highly electroconductive, with no need for doping or further treatment.