Files
Abstract
Post-polymerization modification of reactive polymer brushes serves as a way to fabricate and design polymeric thin films that can be precisely tuned for desired applications. When combined with click chemistry (reactions that are fast, high yielding, and react with high fidelity), post-polymerization modification is further simplified, allowing for the design of even more complex surfaces. Herein, a new click reaction, sulfur fluoride exchange (SuFEx) chemistry, is studied for post-polymerization of reactive polymer brushes, and aminolysis of well-studied poly(pentafluorophenyl acrylate) (Poly(PFPA)) brushes are used for the generation of complex morphologies and self-sorting multi-functional surfaces.First, the conditions, reactivities, and limitations of SuFEx chemistry in polymer brush systems are extensively studied with variations of the brush systems, catalysts, and reactants. Studies on the kinetics of the reaction as well as product identification provide guidance for using this reaction in polymer brush systems as well as give further evidence for elucidation of the reaction mechanism.Complex morphological features and surfaces are also generated and studied in poly(PFPA) brush films. Surface creasing, a failure mechanism of soft materials when exposedto substantial stress, is induced through the confined reaction of Jeffamine M-2070, an amine bearing copolymer of poly(ethylene oxide) and poly(propylene oxide), with the brush surface. The variables governing and controlling crease formation in poly(PFPA) polymer brushes as well as the underlying mechanism are investigated in order to better control, understand, and ultimately expand this phenomenon to other polymer brush systems.Poly(PFPA) brushes are additionally used to fabricate a self-sorting surface with three orthogonal click reactions. Using poly(PFPA) as a scaffold, an amine-bearing strained alkyne and an amine-bearing sulfonyl fluoride were patterned onto the surface and reacted with complementary functionalities for aminolysis, strain-promoted alkyne azide cycloaddition, and SuFEx chemistry in one reaction vessel. This results in a surface that can self-sort three orthogonal reactions to pattern chemical functionalities as well as differing morphologies.Finally, poly(PFPA) polymer networks are fabricated using a photoactive cross-linker in order to create dense reactive polymer films that can be fabricated simply, scaled for industrial use, and expanded to other surfaces with no surface pretreatment required.