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Polycarbonates bearing linear carbonate linkages and polyether segments have demonstrated to be highly attractive solid electrolyte candidates for the design of safe energy storage devices, for exa...

We report on the synthesis of a new polymer ionic liquid (PIL) based on polyvinylimidazolium bearing a pendent nitroxide radical on each monomer unit. Firstly, the quaternization of 1-vinylimidazole by a brominated alkoxyamine, i.e. a protected tetramethylpiperidinyloxy (TEMPO) nitroxide, was achieved. Then, the bromide anion was substituted by anion exchange reaction for the bis(trifluoro-methanesulfonyl)imide (TFSI) anion. The as-obtained monomer was successfully polymerized by free radical polymerization at low temperature (40 °C) by using 2,2′-azobis(4-methoxy-2.4-dimethyl valeronitrile) as initiator. Finally, the C O bond of the alkoxyamine pendant groups was thermally cleaved releasing the redox-active TEMPO nitroxide radicals. The PIL bearing TEMPO groups was coated onto a carbon nanotubes buckypaper and tested as cathode in a lithium ion battery. Such battery remarkably exhibits a high charge/discharge rate capability, e.g. at 60C the full charge is reached in 1 min and a high cycling stability; 100% of the initial capacity 60 mA h/g is kept after 1300 cycles.

Hierarchical porous N-doped carbon (NPC) is prepared by pyrolysis of poly(methyl methacrylate) (PMMA) particles decorated by graphene oxide (GO) and polypyrrole (PPy) as precursors and used as anode for lithium-ion batteries. The composite precursors with different diameter and composition (PMMA/GO/PPy-A and B) were conveniently prepared by dispersion polymerization of methyl methacrylate in the presence of graphene oxide as stabilizer in aqueous medium, followed by addition of pyrrole and its oxidative polymerization. After pyrolysis, the resulting NPC composites with hierarchically structured macro- and mesopores exhibit high surface area (289–398 m2/g) and different N-doping levels (7.46 and 4.22 wt% of nitrogen content). The NPC with the highest N-doping level (7.46 wt%) shows high reversible capacities of 831 mAh/g at 74.4 mA/g (C/5) after 50 cycles and excellent rate performances.

In the last few years, polycarbonates have been identified as alternatives to poly(ethylene oxide) as polymer electrolytes for lithium battery applications. In this work, we show the design of CO2-sourced polycarbonates for their use in room temperature operating lithium batteries. Novel functional polycarbonates with alternating oxo-carbonate moieties and polyethylene oxide segments are synthesized by the facile room temperature (rt) organocatalyzed polyaddition of CO2-sourced bis(aalkylidene carbonate)s (bis-aCCs) with polyethylene oxide diols. The effect of the molar mass of olyethylene oxide on the ionic conductivity and thermal properties of poly(oxo-carbonate)s is investigated. The best candidate shows a low glass transition temperature of 44 C and a high ionic conductivity of 3.75 10 5 S cm 1 at rt when loaded with 30 wt% bis(trifluoromethanesulfonyl)imide salt (LiTFSI) without any solvent. An all-solid semi-interpenetrated network polymer electrolyte (SIN-SPE) is then fabricated by UV cross-linking of a mixture containing specifically designed poly(oxo-carbonate) bearing methacrylate pendants, diethylene glycol diacrylate and the previously described poly(oxocarbonate) containing LiTFSI. The resulting self-standing membrane exhibits a high oxidation stability up to 5 V (vs. Li/Li+), an ionic conductivity of 1.1 10 5 S cm 1 at rt (10 4 S cm 1 at 60 C) and promising mechanical properties. Assembled in a half cell configuration with LiFePO4 (LFP) as the cathode and lithium as the anode, the all-solid cell delivers a discharge capacity of 161 mA h g 1 at 0.1C and 60 C, which is very close to the theoretical capacity of LFP (170 mA h g 1). Also, a stable reversible cycling capacity over 400 cycles with a high coulombic efficiency of 99% is noted at 1C. Similar results are obtained at rt provided that 10 wt% tetraglyme as a plasticizer was added to the SIN-SPE. -Fonds National pour la Recherche Scientifique” (F.R.S.-FNRS) -Fonds Wetenschappelijk Onderzoek– Vlaanderen (FWO) -EOS project no. 019618F (ID EOS: 30902231). - CESAM Research Unit. - European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 -Basque Government through ETORTEK Energigune 2013 and IT 999-16. - Spanish Ministry of Education, Culture and Sport for the predoctoral FPU fellowship received

The cobalt-mediated radical polymerization (CMRP) of new ionic liquid monomers (ILMs), vinyl imidazolium functionalized with redox-active free radical 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)VIm and its CMR copolymerization with vinyl imidazolium units functionalized with triethylene oxide (TEG)VIm produced a well-defined PILs (co)polymers. The controlled nature of (co)polymerization can be seen from the linear first-order kinetic plot, linear evolutions of the molar mass with total monomer conversion and the low polydispersity of the resulting (co)polymers. By combining the redox activity of (TEMPO)PVIm and remarkable ionic conductivity of (TEG)PVIm, outstanding rate capability performance was achieved with a remarkable capacity of 69 mAh g−1 at 60C. The obtained organic electrode can serve as sustainable electrodes in lithium ion batteries.

The performance of lithium and sodium ion batteries relies notably on the accessibility to carbon electrodes of controllable porous structure and chemical composition. This work reports a facile synthesis of well-defined porous N-doped carbons (NPCs) using a poly(ionic liquid) (PIL) as precursor, and graphene oxide (GO)-stabilized poly(methyl methacrylate) (PMMA) nanoparticles as sacrificial template. The GO-stabilized PMMA nanoparticles were first prepared and then decorated by a thin PIL coating before carbonization. The resulting NPCs reached a satisfactory specific surface area of up to 561 m2/g and a hierarchically meso- and macroporous structure while keeping a nitrogen content of 2.6 wt %. Such NPCs delivered a high reversible charge/discharge capacity of 1013 mA h/g over 200 cycles at 0.4 A/g for lithium ion batteries (LIBs), and showed a good capacity of 204 mA h/g over 100 cycles at 0.1 A/g for sodium ion batteries (SIBs)., Comment: 14 pages, 9 figures

To explore the effectiveness of monofluorinated isoindigo as an electron-deficient building block in push-pull conjugated polymers for organic solar cell applications, four low bandgap copolymers are effectively synthesized and characterized. The effects of fluorine introduction, thiophene spacer length and polymer molar mass on the general electro-optical polymer characteristics, thin film blend microstructure and electronic performance are investigated. Isoindigo monofluorination effectively improves the power conversion efficiency from 2.8 up to 5.0% upon molar mass optimization, without using any processing additives or post-treatments.

A new strategy for the synthesis of a well-defined redox active polymer, a polyacrylate bearing TEMPO, and its grafting onto a gold substrate is described. It consists of polymerizing an acrylate bearing an alkoxyamine by RAFT, followed by aminolysis of the trithiocarbonate chain-end into a thiol that is exploited for the polymer grafting onto the gold sensor. Thermal activation of the alkoxyamine under air provides the redox polymer with a high yield. Its electroactivity is evaluated by a electrochemical quartz crystal microbalance (EQCM).

To establish a correlation between the molecular structure, physicochemical properties, thin film morphology, charge carrier mobility and photovoltaic performance of isoindigo-based electron donor type molecular semiconductors, a series of branched and linear A2–D–A1–D–A2 small molecules (A = acceptor, D = donor) are synthesized. The extended π-conjugated molecular chromophores have an electron-accepting isoindigo core, a bridging oligothiophene electron donor part and terminal octyl cyanoacrylate acceptor moieties. Their photophysical, thermal and electrochemical properties are analysed and the materials are applied in organic field-effect transistors and bulk heterojunction organic solar cells. Compared to an analogous benzothiadiazole-based small molecule, the isoindigo core deepens the HOMO energy level, enabling higher open-circuit voltages in organic solar cells. The linear isoindigo-based small molecule shows an enhanced hole mobility compared to the branched derivatives. The best power conversion efficiency of the investigated set is also obtained for the solar cell based on the linear (CA-3T-IID-3T-CA-l) donor molecule in combination with PC71BM.

Poly(ionic liquid)s (PILs) have attracted considerable attention as innovative single-ion solid polyelectrolytes (SPEs) in substitution to the more conventional electrolytes for a variety of electrochemical devices. Herein, we report the precise synthesis, characterization, and use as single-ion SPEs of a novel double PIL-based amphiphilic diblock copolymer (BCP), i.e., where all monomer units are of N-vinyl-imidazolium type, with triethylene glycol pendant groups in the first block and a statistical distribution of N-vinyl-3-ethyl- and N-vinyl-3-perfluorooctyl-imidazolium bromides in the second block. BCP synthesis is achieved directly in water by a one-pot process, by cobalt-mediated radical polymerization-induced self-assembly (CMR-PISA). A subsequent anion exchange reaction substituting bis(trifluoromethylsulfonyl)imide (Tf2N–) for bromide (Br–) counter-anions leads to PIL BCPs with two different lengths of the first block. They demonstrate ionic conductivity σDC = 1–3 × 10–7 S cm–1, as determined by ...

We report a facile and scalable process to prepare nanostructured 3D porous networks combining graphene, N-doped carbon and silicon nanoparticles (G@Si@C) as a promising anode material for batteries. It consists of preparing polymethylmethacrylate particles decorated by Si/graphene oxide and polypyrrole (PPy) in a one-pot process, followed by an appropriate thermal treatment that decomposes PMMA and converts graphene oxide into graphene and polypyrrole into N-doped carbon. The so-formed electrically conducting 3D porous network containing Si nanoparticles inside the cell walls accommodates the large volume changes of Si during charging/discharging and provides a fast electrolyte penetration/diffusion. Therefore, the designed G@Si@C material presents an excellent reversible capacity of 740 mA h g−1 at a current density of 0.14 A g−1 based on the total mass loading of the composite, with more than 99% coulombic efficiency, high rate capability and good cyclability, suggesting great potential for application as an anode material for lithium-ion batteries.

We report on the synthesis of new thermally cross-linkable all-conjugated diblock copolymers composed of a poly(3-hexylthiophene) (P3HT) block and an acrylate-functionalized polythiophene block. These copolymers are then used in bulk heterojunction (BHJ) solar cells with [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and their photovoltaic performances are compared with standard P3HT/PCBM devices. Thermal cross-linking of the functional copolymers/PCBM blends is performed to improve the thermal stability of the active layer. BHJ photovoltaic cells with cross-linkable copolymers and PCBM show initial power conversion efficiencies slightly lower than that of P3HT devices. However, solar cells with cross-linkable copolymers retain more than 85% of their initial power efficiency value after 165 h of thermal annealing (accelerated aging test), whereas the same devices with P3HT retain less than 65% of their initial power efficiency. This improvement of the thermal stability of BHJ photovoltaic cells is the...

We report on a convenient and simple process to prepare highly regioregular poly(thiophene)-based multiblock copolymers by a novel thermally induced coupling reaction. Diblock copolymers of 3-hexylthiophene (3HT) and 2,5-dibromo-3-(2-(2-tetrahydropyranyl-2-oxy)ethyl)thiophene (THPET) end-capped by a nickel complex (Br-P3HT-b-PTHPET-Ni(dppp)Br) are first prepared using Ni(dppp)Cl2 as catalyst at 30 °C by Grignard metathesis polymerization (GRIM process). The coupling of these α-bromo, ω-Ni(dppp)Br telechelic diblock copolymers then occurs by heating the solution of the copolymer at 80 °C for a few hours without adding any additional reagent. Reactions are complete in only 10 min when heating the copolymer at 120 °C using microwaves. The deprotection of the alcohol groups of PTHPET blocks allows further modifications such as the incorporation of acrylates by esterification. AFM analysis on thin films shows the influence of the nature of side chains (protected alcohol or acrylate), the molecular weight, and ...

This article reports the synthesis and characterization of a new polythiophene derivative phenoxy-substituted, the poly[3-(4-octylphenoxy)thiophene] (POPOT). The oxidative polymerization was found to yield low molecular weight material, whereas a modified Grignard metathesis (GRIM) yielded polymers of high molecular weights. One- and two-dimensional NMR indicated the latter to be highly regioregular. POPOTs exhibited higher thermal stabilities than equivalent alkoxy-substituted polythiophenes and exhibited red shifts in the absorption spectra with respect to equivalent. The absorption spectra showed a red shifted λmax at 540 nm in tetrahydrofuran solutions and 580 nm in spin-coated films, with respect to poly(3-alkylthiophene)s. A further red shift of 40 nm in going from solution (540 nm) to solid states (580 nm) is correlated with results from density functional theory electronic structure calculations. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7505–7516, 2008

cited By 30; International audience; Highly regioregular poly[3-(4-octylphenylthiophene)] (POPT) was prepared to study the influence of phenyl groups as substituents on photovoltaic and thermal properties with respect to poly(3-hexylthiophene) (P3HT). The UV-visible absorption spectra of spin-coated films of POPT exhibited an extended absorption towards the near infrared. Differential scanning calorimetry showed the poor tendency of POPT to crystallise. In order to retain the extension in absorption and increase crystallinity, poly(3-hexylthiophene)-block-poly(3-tolylthiophene) (P3HT-b-P3TT) samples with varying ratios of P3HT and P3TT were prepared. Thermal fractionation by successive self-nucleation and annealing indicated that crystallites of P3HT were influenced by the P3TT block within the copolymers. Thermogravimetric analysis showed that thermal stabilities increased with increasing fractions of phenyl groups. Photovoltaic results of these materials blended with [6,6]-phenyl C61 butyric acid methyl ester (PCBM) are presented and discussed. © 2007 Elsevier B.V. All rights reserved.

The preparation of α,α,β-trisubstituted β-lactones has opened the route to living anionic ring-opening polymerization of these monomers. Therefore, transfer reactions due to hydrogen abstraction were limited and it is now possible to strickly control sample molecular weight. Moreover, living end-groups lead to the preparation of block co-polymers with block controlled lenghts. In the same way, high-molecular-weight statistical co-polymers have been synthesized. Hydrolyzable micelles and nanoparticles will be prepared from these co-polymers after chemical modifications to adjust the hydrophilic/hydrophobic balance.

cited By 12; International audience; A combined theoretical and experimental investigation of the electronic structure and optical properties of poly(3-hexylthiophene) (P3HT), poly[3-(4-octylphenyl)thiophene] (POPT) and poly[3-(4-octylphenoxy)thiophene] (POPOT) is reported. In comparison with P3HT, POPT and POPOT exhibit better stabilities and the presence of an oxygen atom and/or a phenyl ring in the side chains enhances conjugation. Quantum chemical calculations have been performed on oligomers of increasing chain length to establish the changes in the electronic and optical properties when going from P3HT to the new derivative POPOT. The knowledge of the structure of these polymers is of utmost importance in understanding their optical properties in different phases (solution and condensed phase). The calculations indicate that, in opposition to P3HT and POPT polymers where the introduction of alkyl chains and the pendant phenyl disturbs the planarity of the backbone of the conjugated segment, POPOT has a better degree of organization in both states: the conjugated chain remains planar even in the presence of the phenoxy groups. Finally, the exciton binding energy is evaluated for these polymers and allows us to conclude that the POPOT is a promising polymer for photovoltaic applications when compared to P3HT and POPT. © the Owner Societies 2012.

International audience; Among the numerous reduced bandgap polymers currently being developed, poly[3-(4-octylphenyl)thiophene)]s (POPT) may present attractive properties for organic solar cells due to its facile preparation and improved absorption with respect to poly(3-hexylthiophene). This article appraises methods of preparation, including the use of diphenyl ether as a reaction medium, and discusses the effects of variations in molar masses, from about 3200 to 65,000 g mol -1 and regioregularity on its optoelectronic properties. The photovoltaic properties of POPT with [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) in bulk heterojunction devices are also discussed in the light of morphological variations, as indicated by atomic force microscopy characterizations. With an initial screening of conditions, namely POPT:PCBM ratios and deposition solvent, a power conversion efficiency of 1.58% was obtained using a relatively high molar mass POPT sample.

Hydrogen bonded assemblies are usually decomposed by polar organic solvents. However, we have succeeded in preparing a strongly associated supramolecular polymer which forms viscous solutions in competitive solvents such as tetrahydrofuran.

37-3 FIELD Section Title:Plastics Manufacture and Processing UMR 7610, Chimie des Polymeres, UPMC Univ Paris 06, Paris, Fr. FIELD URL: written in English; We report the straightforward photo-polymn. of polyacrylate films contg. bis-urea based self-assembled nanotubes. The obtained materials are characterized by gas adsorption measurements, 129Xe NMR spectroscopy and WAXS. The presence of the bis-ureas is shown by butane adsorption (at 273 K and ambient pressure) to be responsible for the formation of a significant microporosity. This porosity is however not detected by the classical argon adsorption procedure (at 77 K and low pressure). This effect is attributed to the contraction of the material at low temp. and pressure, and may be of general concern for other org. porous materials. One of the potential advantages of the present materials is that the porosity results from the self-assembled nanotubes and should therefore be independent of the matrix mech. properties. It should in particular be possible to adjust the flexibility of the matrix by changing the monomer compn. [on SciFinder(R)]

International audience; Poly[3-(4-octylphenyl) thiophene] (PORT) and poly[3-(4-octylphenoxy) thiophene] (POPOT) with high head-to-tall regioregularitlis have been synthesised and photovoltaic properties have been investigated. POPT-blend-PCBM exhibits an interesting behaviour in bulk heterojunction whereas POPOT presents poor photovoltaic performances. UV-visible absorption and AFM images of the blends are presented to explain these results. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA.

International audience; Various poly[3-(4-octylphenyl)thiophene]s (POPTs) were prepared either by oxidative polymerisation or by chain-growth Grignard metathesis (GRIM). In accordance with previous results, the former polymerisation yielded polydisperse POPT. The method based on the GRIM reaction made possible the preparation of medium and higher molecular weight polymers with lower polydispersities. The POPTs were found to have band-gaps of ca. 1.7 eV. The photovoltaic characteristics of POPTs-blend-[6,6]-phenyl C61 butyric acid methyl ester (PCBM) composites under AM 1.5 conditions in standard ITO/PEDOT-blend-PSS/ POPT-blend-PCBM/LiF/Al solar cells were studied. It was found that POPT prepared via GRIM could deliver greater efficiencies than its equivalent prepared by oxidative polymerisation. It is expected that access to even higher molecular weight POPTs may improve the efficiencies of such devices.

We report on a simple process for the chemisorption of poly(thiophene)-based block copolymers onto ITO substrates. Two poly(thiophene) block copolymers functionalized by acrylates on the second block are prepared by the Grignard Metathesis (GRIM) process. The first block is composed of poly(3-hexylthiophene) (P3HT) and the second block is either a polythiophene bearing an acrylate group on each monomer unit (PAcET), or a polythiophene bearing both acrylate and poly(ethylene glycol) side chains (P(AcET-co-PEGET)). After characterizing their macromolecular parameters and optical properties, we investigate their ability to self-assemble into micelles in DMF solutions. This solvent is required for the electrografting procedure that is used for strongly anchoring the polymer to ITO. These micelles are expected to be formed by a P3HT core and a PAcET or P(AcET-co-PEGET) shell. When PEG side chains are present in the second block, the copolymer nicely self-assembles into micelles decorated by acrylates. Cathodic polarization of ITO induces chemisorption and polymerization of acrylate groups, leading to an adherent organized film of poly(thiophene)-based micelles. The optical absorption spectra show that the electrografted polymer chains have a degree of π-electron conjugation similar to that of crystalline P3HT films. In the absence of the PEG chains, the copolymer does not organize into micelles, due to the low stabilizing ability of the second block in DMF.