Surface-Initiated Ring-Opening Metathesis Polymerization: A Versatile Route to Produce Novel Materials and Biomimetic Coatings
Escobar, Carlos Andres
The modification of materials and surfaces with fluorocarbons enables ultralow surface energies in the development of numerous applications of cutting-edge science and technology. The use of partially fluorinated materials offers advantages in terms of cost and synthetic flexibility, and in some cases, performance, when compared to all–fluorocarbon materials. This research employs a surface-initiated polymerization (SIP), namely surface-initiated ring-opening metathesis polymerization (SI-ROMP), to grow partially fluorinated coatings with critical surface tensions as low as 9 mN/m that establish new standards in thickness with tremendous control over microscale surface texturing. SIP techniques provide robust chemisorption, diverse chemical functionality, control over film growth, and the ability to uniformly coat planar and non-planar surfaces. Although SIP methods have been previously used to deposit partially fluorinated films, the ability to grow such films with thicknesses above a few micrometers, with controlled textures, or within nanoporous materials has not been demonstrated prior to this work. Accordingly, this dissertation focuses on: (1) the fabrication and characterization of novel partially fluorinated/inorganic composites by employing SI-ROMP within nanoporous architectures to create membranes with tunable wettability and ion transport; (2) the amplification of the SIP of partially fluorinated polymer films to fabricate specialty coatings that yield thicknesses from 4 – 12 µm in as little as 15 min of polymerization. Remarkably, these films exhibit resistance against ion transport in excess of 10 GΩ•cm^2, which is the highest value ever reported for SIP films; and the development of a new SIP-based approach to (3) fabricate microscale surface features with height modulation and to (4) reproduce the complex surface topographies of superhydrophobic natural surfaces onto solid supports. This process enables the preparation of microtextured films and novel biomimetic coatings that reproduce superhydrophobic plant leaves, and could radically impact applications such as self-cleaning surfaces and chemical- and corrosion-resistant coatings.