Publication Date

Fall 2019

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Advisor

Chester . Simocko

Keywords

Brushes, Mixed, Polymer, Stability, Thermal

Subject Areas

Chemistry

Abstract

Nanostructures, features that are generated on the scale of 1-100 nm, have potential in

many applications including semiconductors and sensors. Mixed polymer brushes, which are composed of two or more unique polymer types covalently tethered to a solid surface, have been shown to give rise to distinct nanostructures. The solid support for these systems can be flat surfaces, such as silicon wafers, or 3-dimensional surfaces, such as nanoparticles. Polymer brushes are mechanically and chemically robust, but their thermal stability is not well understood. Because many potential applications require elevated temperatures, understanding and tuning their thermal stability is important. We studied the thermal properties of homo, binary, and ternary polymer brushes consisting of polystyrene, poly(methyl methacrylate), poly(4-vinyl pyridine), and poly(2-vinyl pyridine). The polymer brushes were synthesized using surface-initiated free radical polymerization and the thickness of the brushes was measured with spectral reflectance. The morphologies of the mixed polymer brushes were characterized by atomic force microscopy. Polymer brushes that had a complete or partial composition of P2VP and P4VP were more thermally stable than brushes that did not have either of these polymers as part of their composition. Based on the thermal stability data, grafting density influences thermal stability more than any other factor, but polymer identity plays an important role as well.

Available for download on Wednesday, February 05, 2025

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