One-pot preparation of ferrocene-functionalized polymer brushes on gold substrates by combined surface-initiated atom transfer radical polymerization and "click chemistry"

Li Qun Xu; Dong Wan; Huifen Flora Gong; Koon-Gee Neoh; En-Tang Kang; Guo Dong Fu

doi:10.1021/la102775y

One-pot preparation of ferrocene-functionalized polymer brushes on gold substrates by combined surface-initiated atom transfer radical polymerization and "click chemistry"

Langmuir. 2010 Oct 5;26(19):15376-82. doi: 10.1021/la102775y.

Authors

Li Qun Xu¹, Dong Wan, Huifen Flora Gong, Koon-Gee Neoh, En-Tang Kang, Guo Dong Fu

Affiliation

¹ Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 809978.

PMID: 20839788
DOI: 10.1021/la102775y

Abstract

A gold substrate with surface-grafted ferrocene functional polymer brushes, or Au-g-PFTMA surface [PFTMA = poly(5-ferrocene-triazolyl methacrylate)], was prepared by a combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and "click chemistry" in one pot, in the presence of 2-azidoethyl methacrylate (AzEMA), ethynyl ferrocene, CuBr catalyst, CuBr(2) deactivator, and pentamethyldiethylenetriamine ligand. Thus, SI-ATRP of AzEMA from the Au substrate (the "grafting from" process) and click chemistry of the ethynyl ferrocene to the azide functional group of AzEMA (the "grafting to" process) proceeded simultaneously to produce the functional PFTMA brushes on the Au surface. Kinetic studies suggest that the reaction involving simultaneous SI-ATRP and click chemistry is still consistent with a controlled/"living" process. The composition and physical properties of the modified gold surface were analyzed by X-ray photoelectron spectroscopy, water contact angle measurement, and cyclic voltammetry. The redox-responsive properties of the ferrocene-functionalized polymer brushes on the Au-g-PFTMA surface were demonstrated in the reversible loading-unloading step of the β-cyclodextrin polymer via host-guest interaction.