Poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl acrylamide) was designed and synthesized as an electrode-active polymer for an organic rechargeable device containing an aqueous electrolyte. The device demonstrated a 1.2 V output voltage, exceeded 2000 charging-discharging cycles, and had a high charging rate performance within 1 min.Polyacrylamide is a well-known hydrophilic soft matter widely used in cell culture, drug delivery, and soil amendment. 1-4 Its applications have been vigorously studied in the biological, medical and agricultural fields. On the other hand, the study of the electronic energy related application has been minor and limited to polymer electrolyte fuel cells. 5 We now report a new application of polyacrylamide as an electrode-active material in organic rechargeable devices.Organic-based electrode-active materials have been paid considerable attention because of their potential to overcome the inherent disadvantages of metal-based electrodes, such as limited raw-material resource and tedious waste process. We have focused on the reversible redox reaction of radical species, such as nitroxide, phenoxyl and galvinoxyl radicals, synthesizing a series of aliphatic polymers bearing pendant radical groups (we call them "radical polymer"), and utilizing them as an electrode-active or charge-storage material in a rechargeable device. 6-13 A typical example of a radical polymer is poly(2,2,6,6tetramethylpiperidinyloy-4-yl norbornene). 10 This polymer contains 2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl (TEMPO) groups which are rapidly, reversibly, and stoichiometrically oxidized to the corresponding oxoammonium cation. The poly(TEMPOsubstituted norbornene) was used as the positive electrode (the cathode) ‡ and coupled with a lithium metal negative electrode (an anode) ‡ in a semi-organic rechargeable device containing a LiPF 6 ethylene carbonate/diethyl carbonate (1/1) solution. The device demonstrated a high charging-discharging performance, such as a 3.6 V output voltage, rapid charging within 1 min, and exceeded 1000 charging-discharging cycles. 12 In addition, a test cell composed of the poly(TEMPO-substituted norbornene) cathode, poly(galvinoxylstyrene) anode and (

We present here the synthesis of two kinds of amphiphilic block copolymers, a diblock copolymer MPEG‐b‐PTAm and a triblock copolymer MPEG‐b‐PLA‐b‐PTAm, which can self‐assemble into micelles with nitroxyl radicals‐containing PTAm segment in the core. The structure of the block copolymers was characterized by 1H NMR and GPC. Dynamic laser light scattering and transmission electron microscopy were used to study the micellar behavior of the two block copolymers in aqueous solution. The micelles carrying nitroxyl radicals in the core can generate electron paramagnetic resonance, which is stable for a period of time up to 8 min even in the presence of reducing reagent such as ascorbic acid. The enhanced stability against the reducing agent was ascribed to the inaccessibility of the nitroxyl radical core placed in the interior of the micelles. Combined with the biocompatibility, these micelles were promising to be used as the EPR probes for bioimaging in vivo. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

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Copolymers composed of PLA and PTAm were prepared by a macromonomer approach. The PLA bearing vinyl group at chain end was copolymerized with 2,2,6,6-tetrametylpiperidine-4-ylacrylamide. The resulted copolymers were oxidized by a peroxide to give PTAm-g-PLA. The structures of the copolymers were confirmed by NMR and FTIR spectroscopy. The comparison of (1)H NMR results and SQUID measurements demonstrated that the oxidation of the PTAm fragment proceeded almost to completion. An MTT assay, cell adhesion and spreading evaluation showed that the copolymers exhibited improved cytocompatibility as compared to the PTAm homopolymer due to the introduction of the biocompatible PLA moiety.

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