Surface-Initiated Polymerization of Perfluoro-n-Alkyl-Norbornenes

The controlled growth of polymer films with tunable properties can be achieved using surface-initiated polymerizations (SIP). Fluorocarbon-containing polymers have applications as protective coatings, biomaterials, membranes, and dielectrics due to their low critical surface energies, dielectric constants, frictional coefficients, and chemical reactivities. However, SIP of fluorinated polymers is difficult due to the steric hindrance of the fluorocarbon group. To circumvent this issue, polymer films are typically fluorinated with additional processing steps. In contrast, the research described in this presentation focuses on the surface-initiated ring-opening metathesis polymerization (SI-ROMP) of perfluoro-n-alkylnorbornenes (pNBFn) to form partially fluorinated polymer films with tunable thicknesses ranging from tens of nanometers to microns. The growth, structure, and properties of the pNBFn films on 2 D gold and 3-D graphitic fiber electrodes will be discussed. The close proximity of the fluorocarbon and hydrocarbon components of the polymers yields unique phase-separated structures and conformations throughout the polymer films as shown by scanning electron microscopy images. Dielectric and interfacial properties are comparable to those of fully fluorinated polymer films and are dependent on the length of the fluorocarbon chains.