Collaborative Research: Polymer Single Crystal-Assisted "Grafting From": A Versatile Approach towards Multicomponent Polymer Brushes with Well-Defined Architectures and Grafting

Drexel University, Philadelphia PA

Investigators

Abstract

The surface properties of a material can be critical to its application (e.g., the adhesive properties of tapes, non-wetting properties of water-repellent garments, and non-stick surface of cookware). Often, the material surface needs to be chemically modified to tailor its properties. In this collaborative research, Professor Bin Zhao of the University of Tennessee Knoxville and Professor Christopher Li of Drexel University develop a viable method for modifying a surface with a polymer containing a well-defined architecture and thus achieving precise control of surface structures and properties. This fundamental chemistry research is expected to advance the field of polymer science and present new opportunities in materials and technology development. Additional broader impacts of the project include education and training of undergraduate and graduate students in both polymer chemistry and physics, preparing a workforce for the polymer (plastics) industry. Polymer chemistry is integrated in outreach activities (e.g., demonstration experiments such as "Foam and Slime Forming" in a Drexel summer outreach program) for high school teachers and students to arouse their interests in science. The Macromolecular, Supramolecular and Nanochemistry Program of the NSF Chemistry Division supports this research to develop a robust and versatile strategy for preparing a variety of well-defined multicomponent polymer brushes on flat solid substrates (e.g., silicon wafers and glass substrates). This research aims to combine polymer single crystal-assisted "grafting to" and surface-initiated "living"/controlled polymerization (i.e., "grafting from") to synthesize brushes with complex architectures, such as Y-shape and loop, and tunable grafting densities. Various polymerization methods (including ring-opening polymerization, atom transfer radical polymerization, and nitroxide-mediated radical polymerization) are used to synthesize the multicomponent polymer brushes. A range of techniques (e.g., atomic force microscopy, x-ray photoelectron spectroscopy, scanning and transmission electron microscopies, grazing incident small-angle X-ray scattering, and wide angle X-ray diffraction) are used to characterize the polymer brush structures and properties.