Redox polymer brushes

FIGURE 12.8 Reversible pH-controlled transformation of the redox-polymer brush (P4VP-Os complex) grafted to an ITO electrode between its electrochemically active and inactive states. The conformational changes of P4VP regulate the activation (pH = 4) or inhibition (pH = 6) of the electron transfer from GOx to the electrode support leading to the reversible... 

Figure 5.12 Reversible pH-controlled transformation of the redox-polymer brush on the electrode surface between electrochemicaUy active and inactive states.

Because of its confinement and uniform polymer constitution, the preorganized polymer brush reacts collectively to environmental stimuh such as changes of the pH or ion strength [171-173], temperature [174], solvent quality or mechanical forces [175, 176], irradiation [177] or redox reactions [178]. 

Mazurowski, M., Gallei, M., Li, J., Didzoleit, H., Stiihn, B., Rehahn, M. (2012). Redox-responsive polymer brushes grafted from polystyrene nanoparticles by means of surface initiated atom Transfer radical polymerization. Macromolecules, 45, 8970-8981. 

Tam, T. K., Omatska, M., Pita, M., Minko, S., Katz, E. (2008). Polymer brush-modified electrode with switchable and tunable redox activity for bioelectronic applications. The Journal of Physical Chemistry C, 112, 8438-8445. 

A comprehensive summary of the syntheses and applications of the ferrocene polymer brushes has been presented. Ferrocene-functionalized polymer brushes covalently bonded or physisorbed on solid substrate surfaces can be readily prepared via well-known surface modification techniques, such as surface-initiated polymerizations, reaction of the end-functional groups of polymer chains with substrate surfaces, and host-guest interaction. These electroactive polymer brushes have found applications in biosensors, anion-exchange chromatography, and redox-controlled modification of surface wetting properties. 

Redox-controlled reversible loading of the -CD polymer on the gold substrates with surface-grafted and ferrocene-functionalized polymer brushes. (Reprinted with permission from Xu et al. 2010. One-Pot Preparation of "Ferrocene-Functionalized Polymer Brushes on Gold Substrates by Combined Surface-Initiated Atom Transfer Radical Polymerization and "Click Chemistry." Langmuir 26 (19) 15376-15382, copyright (2010) American Chemical Society.)... 

Figure 6.4 Reversible pH control of the redox-poly polymer brush between electrochemically active and inactive states.

Gohiz AA, Kaule T, Untch MB, Kobnan K, Berger R, Gutmann JS (2013) Redox active polymer brushes with phenothiazine moieties. ACS Appl Mater Interfaces 5 2485-2494... 

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