X. J. and H. Y. C. contributed equally to this work. The authors gratefully acknowledge support from the NSF in form of a CAREER grant (DMR-0449462) and funding from the NSF under MRI program (DMR 0420785). We thank Professor Ronald G. Larson, University of Michigan, for use of the fluorescence microscope.
Vapor-Based Initiator Coatings for Atom Transfer Radical Polymerization†
Article first published online: 18 DEC 2007
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 18, Issue 1, pages 27–35, January, 2008
How to Cite
Jiang, X., Chen, H.-Y., Galvan, G., Yoshida, M. and Lahann, J. (2008), Vapor-Based Initiator Coatings for Atom Transfer Radical Polymerization. Adv. Funct. Mater., 18: 27–35. doi: 10.1002/adfm.200700789
- Issue published online: 4 JAN 2008
- Article first published online: 18 DEC 2007
- Manuscript Revised: 21 SEP 2007
- Manuscript Received: 18 JUL 2007
- NSF. Grant Numbers: DMR-0449462, DMR 0420785
- Biomedical applications;
- Chemical vapor deposition;
A novel polymeric initiator coating for surface modification via atom transfer radical polymerization (ATRP) is reported. The synthetic approach involves the chemical vapor deposition of [2.2]paracyclophane-4-methyl 2-bromoisobutyrate and can be applied to a heterogeneous group of substrates including stainless steel, glass, silicon, poly(dimethylsiloxane), poly(methyl methacrylate), poly(tetrafluoroethylene), and polystyrene. Surface analysis using X-ray photoelectron spectroscopy and Fourier-transformed infrared spectroscopy confirmed the chemical structure of the reactive initiator coatings to be consistent with poly[(p-xylylene-4-methyl-2-bromoisobutyrate)-co-(p-xylylene)]. Appropriate reactivity of the bromoisobutyrate side groups was confirmed by surface initiated atom transfer radical polymerization of a oligo(ethylene glycol) methyl ether methacrylate. After solventless deposition of the CVD-based initiator coating, hydrogel films as thick as 300 nm could be conveniently prepared within a 24 h timeframe via ATRP. Moreover, the polymerization showed ATRP-specific reaction kinetics and catalyst concentration dependencies. In addition, spatially controlled deposition of the initiator coatings using vapor-assisted microstructuring in replica structures resulted in fabrication of spatially confined hydrogel microstructures. Both protein adsorption and cell adhesion was significantly inhibited on areas that were modified by surface-initiated ATRP, when compared with unmodified PMMA substrates. The herein described initiator coatings provide a convenient access route to controlled radical polymerization on a wide range of different materials. While demonstrated only for a representative group of substrate materials including polymers, metals, and semiconductors, this method can be expected to be generically applicable – thereby eliminating the need for cumbersome modification protocols, which so far had to be established for each substrate material independently.