Poly(2-(dimethylamino)ethyl methacrylate) brushes fabricated by surface-mediated RAFT polymerization and their response to pH

• Published in: European polymer journal 2013-10, Vol.49 (10), p.3350-3358
• Main Authors: Zengin, Adem, Karakose, Gamze, Caykara, Tuncer
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; pH-responsive surfaces; Physicochemistry of polymers; Poly(2-(dimethylamino)ethyl methacrylate); Polymer brushes; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts; Surface-mediated RAFT polymerization
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2013.07.005

[Display omitted] •Poly(DMAEMA) brushes were synthesized by the surface-mediated RAFT polymerization.•Kinetic studies revealed a linear increase in poly(DMAEMA) film thickness with polymerization time.•Poly(DMAEMA) brushes showed good pH responsive property. In this study, well-defined, high density poly(2-(dimethylamino)ethyl methacrylate) [poly(DMAEMA)] brushes were fabricated by the combination of the self-assembly of a monolayer of RAFT agent and surface-mediated RAFT polymerization. The whole fabrication process of the poly(DMAEMA) was followed by water contact angles, grazing angle-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. Kinetic studies revealed a linear increase in poly(DMAEMA) film thickness with polymerization time, indicating that the chain growth from the surface was a controlled process. Characterization of the poly(DMAEMA) brushes, such as molecular weight and thickness determination, were measured by gel permeation chromatography, and ellipsometry, and the grafting density was estimated. The pH response of the poly(DMAEMA) brushes was further investigated and the results verified the “brush-like” to “mushroom-like” transition of the poly(DMAEMA) chains due to the reversible protonation/deprotonation upon changing the solution pH.