Date of Award

Spring 5-2017

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

Committee Chair

Derek L. Patton

Committee Chair Department

Polymers and High Performance Materials

Committee Member 2

Sarah E. Morgan

Committee Member 2 Department

Polymers and High Performance Materials

Committee Member 3

Robson F. Storey

Committee Member 3 Department

Polymers and High Performance Materials

Committee Member 4

Sergei Nazarenko

Committee Member 4 Department

Polymers and High Performance Materials

Committee Member 5

Yoan C. Simon

Committee Member 5 Department

Polymers and High Performance Materials

Abstract

The combination of surface-initiated polymerization (SIP) and postpolymerization modification (PPM) is a powerful technique for the fabrication of functional soft surfaces. Better understanding the influence of the aforementioned factors on the PPM effectiveness is valuable for fulfilling the potential of the PPM approach for the fabrication of functional soft surfaces. Specifically, by carefully balancing modification reactivity and limitation of mass transport, polymer brush with composition heterogeneity and gradient along the normal direction of the surface otherwise unattainable by methods of direct polymerization can be fabricated via the PPM approach which opens doors to new routes to polymer brush with complex functionality and morphology (i.e. buckling). This dissertation is focused on designing and synthesizing polymer brush surfaces with complex molecular architectures and morphologies with specific emphasis on improving the understanding of PPM effectiveness and the distribution of post modification moieties on grafted polymer chains.

In the first study, microwave-assisted surface-initiated polymerization (μW-SIP) was developed and employed to demonstrate the synthesis of polymer brushes on silicon and quartz substrates. The μW-SIP approach shows significant enhancements in polymer brush thickness at reduced reaction times and monomer concentration.

In the second study, the postpolymerization modification of a poly(2-isocyanatoethyl methacrylate) (pNCOMA) brush surfaces with deuterated thiols of different sizes was studied and the depth profiles of the distribution of the modified brush were drawn using neutron reflectometry analysis. By applying a sequential PPM strategy, polymer brush with tapered block copolymer architectures was synthesized.

In the third study, a poly(styrene-alt-maleic anhydride) (pSMA) copolymer brush was synthesized in an effort to fabricate pendent polyfunctional thiols polymer brush for further thiol-ene modifications. Furthermore, the pSMA brush itself was found to be a stable and versatile platform for amine modification.

In the last study, a straightforward PPM approach, utilizing the knowledge gained in previous studies, to engineer ultrathin polymer brush surfaces with tunable wrinkled morphologies was demonstrated by creating a modulus mismatch between the top layer and bottom of the polymer brush via selectively crosslinking of the outer layer of pSMA brushes by balancing the rate of PPM and reactive molecule diffusion.

ORCID ID

0000-0001-7372-4956

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