Rapid Deposition of Layered Polymer Films by Ring-Opening Metathesis Polymerization during Spin Coating

The surface composition of a polymer thin film determines the interactions of the film with its environment and equips the film for specific applications, such as a coating, sensor, adhesive, antifoulant, or membrane. We report a rapid and versatile method to tailor the surface properties of polymer films by growing functional top layers on top of inexpensive bottom layers through sequential depositions of different monomer solutions onto a catalyst-coated surface. This method of synthesizing layered films formally expands spin coating ring-opening metathesis polymerization (scROMP), which efficiently integrates polymer film synthesis and deposition into one rapid process, converting the sequential monomers into layered polymer films in under 3 min with less than 600 μL of solvent for a 2.25 cm² film. The scROMP approach is shown here to synthesize films with polymers of >500 kDa molecular weights and <1.15 dispersities and to effectively stack two or more layers of distinct functionalities that constitute the bulk and surface regions of the film. Thicknesses of the top layers can be dramatically altered by monomer concentration, and the top layer can be extremely thin (within the nanometer range) or as thick as 3× the bottom layer (>15 μm) for certain compositions. As potential applications, we demonstrate the syntheses of unique layered films with specialized properties such as omniphobicity, superhydropilicity, and protein resistance.