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ABSTRACT: Branching was detected in polyacrylates synthesised through radical polymerization via solution-state NMR, while inconsistencies have been reported for the determination of the molar mass of hydrophilic polyacrylates using aqueous-phase and organic-phase size-exclusion chromatography. In this work, poly(sodium acrylate)s, PNaAs, of various topologies were separated for the first time using free-solution capillary electrophoresis (CE). Free-solution CE does not separate the PNaAs by their molar mass, similarly to separations by liquid chromatography in the critical conditions, rather by different topologies (linear, star branched, and hyperbranched). The electrophoretic mobility of PNaAs increases as the degree of branching decreases. Separation is shown to be not only by the topology but also by the end groups as expected for a separation in the critical conditions: replacing a relatively bulky nitroxide end group with hydrogen atom yielded a higher electrophoretic mobility. This novel method, capillary electrophoresis in the critical conditions enabled, for the first time, the separation of hydrophilic polyacrylates according to their topology (branching) and their chain ends. This will allow meaningful and accurate characterization of their branched topologies as well as molar masses and progress in for advanced applications such as drug delivery or flocculation.
Analytical and Bioanalytical Chemistry 06/2013; · 3.78 Impact Factor
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ABSTRACT: For polymer synthesis upon visible light, actual photoinitiator operates in a restricted part of the spectrum. As a consequence, several photoinitiators are necessary to harvest all of the emitted visible photons. Herein, 2,7-di-tert-butyldimethyldihydropyrene is used for the first time as a multicolor photoinitiator for the cationic polymerization of epoxides. Upon addition of diphenyliodonium hexafluorophosphate and optionally N-vinylcarbazole, the originality of this approach is to allow efficient monomer conversions under various excitation light sources in the 360-650 nm wavelength range: halogen lamps, and light-emitting and laser diodes. The synthesis of an interpenetrated polymer network from an epoxide/acrylate blend using a red light at 635 nm is also feasible. The formed polymer material exhibits a photochromic character.
Macromolecular Rapid Communications 06/2013; · 4.60 Impact Factor
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ABSTRACT: There have been considerable interests in attempting to reverse the deficit due to a spinal cord injury by restoring neural pathways through the lesion and by rebuilding tissue network. In order to provide an appropriate micro-environment for regrowing axotomized neurons and proliferating and migrating cells, we have implanted small block of pHPMA hydrogel into the hemisected T10 rat spinal cord. Locomotor activity was evaluated once a week during 14 weeks with the BBB rating scale in an open field. At the 14th week after spinal cord injury, the reflexivity of the sub-lesional region was measured. We also monitored the ventilatory frequency during an electrically induced muscle fatigue known to elicit the muscle metaboreflex and increase the respiratory rate. Spinal cords were then collected, fixed and stained with anti-ED-1 and anti-NF-H antibodies, and FluoroMyelin. We show in this study that hydrogel implanted animals exhibit 1) an improved locomotor BBB score, 2) an improved breathing adjustments to electrically-evoked isometric contractions, 3) an H-reflex recovery close to Control animals. Qualitative histological results put in evidence higher accumulation of ED-1 positive cells (macrophages/monocytes) at the lesion border, a large number of NF-H positive axons penetrating the applied matrix, and myelin preservion rostrally and caudally to the lesion. Our data confirm that pHPMA hydrogel is a potent biomaterial that can be used for improving neuromuscular adaptive mechanisms and H-reflex responses after spinal cord injury.
04/2013; · 3.75 Impact Factor
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ABSTRACT: The formation of a di-tert-alkyl nitroxide has been observed by Electron Spin Resonance during the exposure of coenzyme CoQ(10), in both the oxidized and reduced forms, to nitrogen dioxide (˙NO(2)) or to nitric oxide (˙NO) in the presence of oxygen. The same kind of nitroxide has been observed also with CoQ(1), CoQ(3) or with 1-phenyl-3-methyl-2-butene, chosen as model compounds. In all cases, the formation of the nitroxide may be justified only by admitting the involvement of the isoprenic chain of the coenzymes and in particular the addition of ˙NO(2) to the double bond. A mechanism which accounts for the formation of the nitroxide as well as the other compounds observed in the reactions is proposed and confirmed by a spectroscopic investigation (FT-IR, (1)H NMR, X-ray analysis) and by ESI-MS.
Organic & Biomolecular Chemistry 01/2013; · 3.70 Impact Factor
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ABSTRACT: The first reported combination of regioselective hydro-defluorination and a ligand exchange reaction during the syntheses of neutral iridium(iii) complexes is presented. Surprisingly, loss of one fluorine atom per ligand combined with a complete ligand exchange reaction on the transition metal were jointly observed during a bridge-splitting and substitution reaction of two different dimeric iridium(iii) precursor complexes with two different ancillary ligands. The regioselectivity of defluorination was evidenced in both cases. The reaction time was identified as a factor strongly impacting the kinetics of the thermally induced reaction.
Dalton Transactions 01/2013; · 3.84 Impact Factor
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ABSTRACT: Nitroxide-mediated polymerization (NMP) is a controlled/living radical polymerization (CLRP) technique that enables the design of well-defined, functional and complex macromolecular architectures. This comprehensive review covers all aspects, features and achievements of NMP, from its discovery to 2012. All topics related to NMP are thoroughly discussed and detailed in-depth: synthetic approaches to nitroxides and alkoxyamines, kinetic aspects and polymerization features, range of controllable monomers, polymer characterization, polymerization processes (ionic liquids, dispersed media, etc.), macromolecular coupling approaches, functionalization strategies, macromolecular architectures, bio-related and hybrid materials, industrial applications as well as environmental constraints.
Progress in Polymer Science 01/2013; 38(1):63–235. · 24.10 Impact Factor
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ABSTRACT: Eleven di- and trifunctional compounds based on a core-pyrene π structure (Co_Py) were synthesized and investigated for the formation of free radicals. The application of two- and three-component photoinitiating systems (different Co_Pys with the addition of iodonium or sulfonium salts, alkyl halide or amine) was investigated in detail for cationic and radical photopolymerization reactions under near-UV-vis light. The proposed compounds can behave as new photocatalysts. Successful results in terms of rates of polymerization and final conversions were obtained. The strong MO coupling between the six different cores and the pyrene moiety was studied by DFT calculations. The different chemical intermediates are characterized by ESR and laser flash photolysis experiments. The mechanisms involved in the initiation step are discussed, and relationships between the core structure, the Co_Py absorption property, and the polymerization ability are tentatively proposed.
Beilstein Journal of Organic Chemistry 01/2013; 9:877-90. · 2.52 Impact Factor
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ABSTRACT: Two new photoinitiators with unprecedented light absorption properties are proposed on the basis of a suitable truxene skeleton where several UV photoinitiators PI units such as benzophenone and thioxanthone are introduced at the periphery and whose molecular orbitals MO can be coupled with those of the PI units: a red-shifted absorption and a strong increase of the molecular extinction coefficients (by a ≈ 20-1000 fold factor) are found. These compounds are highly efficient light-harvesting photoinitiators. The scope and practicality of these photoinitiators of polymerization can be dramatically expanded, that is, both radical and cationic polymerization processes are accessible upon very soft irradiation conditions (halogen lamp, LED…︁) thanks to the unique light absorption properties of the new proposed structures.
Macromolecular Rapid Communications 12/2012; · 4.60 Impact Factor
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ABSTRACT: A series of styrene-substituted 1,3,4-oxadiazoles has been designed and investigated as new low-molecular-weight organogelators. The photophysical properties of the resulting thermoreversible organogels have been characterized by UV/Vis absorption and luminescence spectroscopies. Surprisingly, the gelation ability of the oxadiazoles depended on the presence of the styrene moiety as gelation of the investigated oxadiazoles did not take place in its absence. Gel formation was accompanied by a modification of the fluorescence of the organogelators in the supramolecular state. UV irradiation of the gels caused a rearrangement of the immobilized 1,3,4-oxadiazoles bearing a styrene moiety by a tandem [4+2] and [3+2] cascade reaction. Structure modification and color change of the gels were also evident upon irradiation.
Chemistry 11/2012; · 5.93 Impact Factor
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ABSTRACT: The photoredox catalysis approach is used to initiate the free radical promoted cationic photopolymerization of N-vinylcarbazole (NVK) under very soft irradiation conditions (halogen lamp, blue or green LED bulbs) using visible-light harvesting photocatalysts (mainly Ir(III) complexes) in iodonium salt and silane containing photoinitiating systems. The reactions were shown to proceed via an oxidative catalytic cycle where the generated free radicals are oxidized into cations. The effect of NVK on this catalytic cycle is discussed. Epoxy/NVK matrixes can also be polymerized. The luminescent properties of the synthesized polymers are presented. ■ INTRODUCTION Poly(vinylcarbazole) (PVK) is a well-known organic semi-conductor involved in the preparation of various optoelectronic devices. Based on its good solubility in common organic solvents, excellent film-forming properties, high glass-transition-temperature (200 °C), and high triplet energy (3.0 eV), PVK is widely used as the hole transport layer of OLEDs and LECs devices. 1 Additionally to this main application, PVK is also investigated as a host material for guest−host systems as its broad emission spectrum overlaps well with the absorption bands of a wide range of dopants. In this last case, emission color of the resulting devices can be controlled by the emission color of the dopant as a Fö rster energy transfer from the host matrice PVK to the guest occurs. Following this approach, a series of OLEDs were notably prepared using iridium(III) complexes as dopants. 2 Up to now, the preparation of the PVK matrix in these applications is realized through thermal reactions. The use of organometallic compounds (e.g., Ir and Ru derivatives) as photocatalysts (PC) under very soft irradiation conditions is now well documented in organic chemistry (see e.g. refs 3−6). The approach has recently been extended to the polymer area through the development of new photoinitiating systems using LED bulbs or green fluorescence bulbs as irradiation sources. 7−9 The use of PCs is also highly versatile: (i) an oxidative catalytic cycle ensures the formation of ions to initiate a ring-opening polymerization (ROP) (for example, the three-component system (PC/iodonium salt (Ph 2 I +)/silane where e.g. PC = tris[2-phenylpyridinato-C 2 ,N]iridium(III) [Ir(ppy) 3 ] generates a silylium ion that initiates the ring-opening polymerization ROP of an epoxide) 7,8b and (ii) a reductive cycle allows the formation of radicals to initiate a free radical polymerization (FRP). 7,8 The formation of poly(vinylcarbazole) (PVK) has been elegantly achieved in previous reports 10 through a free radical promoted cationic photopolymerization (FRPCP) process using cleavable photoinitiators. In the same way, an epoxy/N-vinylcarbazole (NVK) matrix was polymerized in the presence of an iodonium salt (the initiation occurs through a NVK/ iodonium salt interaction). 11 However, these works required a UV light for the photoinitiator excitation and the experiments were carried out in degassed media. The goals of the present paper are twofold. First, we propose (i) to investigate the photopolymerization of NVK upon visible light irradiations and under air and (ii) to explore the possibility to incorporate, at the same time, iridium complexes in the
Macromolecules 04/2012; 45(10):4134−4141. · 5.17 Impact Factor
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ABSTRACT: We report on formation of a new surface covalent organic framework (SCOF) based on a sequential polymerization in two stages. The bifunctional precursor used, p-bromo-benzene boronic acid (BBBA), was vapor deposited in ultra-high-vacuum conditions on a Au(111) surface. In a first step the boronic acid moieties reacted to form trimers linked by covalent boroxine rings. In a second step, an Ullmann coupling reaction was thermally activated to form C− C bonds between the trimers, leading to the final polymeric network. By this procedure the growth mechanism was optimized and the polymerization reaction yield could approach 100%. A well-extended network was obtained, differing from the ideal honeycomb-like network by a substantial number of nonhexagonal pores, which are intrinsic defects to the polymer structure. A comparison of the two competing reactions provides new insights into the complex mechanisms governing growth of two-dimensional covalent networks. ■ INTRODUCTION Supramolecular self-assembly at surfaces has proven in the last two decades to be very efficient for creating highly organized atomically controlled organic nanostructures. 1,2 The possibility of extending its concepts to formation of covalent bonds between molecular tectons has attracted recent focus, and demonstrations of covalent polymerization performed directly at surfaces have opened promising perspectives. 3−6 Successful formation of two-dimensional polymers is expected to have a great impact on many fundamental and applied aspects of science. However, the search for a synthetic route leading to reliable and robust periodic covalent molecular sheets is still in its infancy. 7 Various strategies in the choice of on-surface chemical reactions are found in the literature. Different chemical functional groups and reaction schemes were used: halogenated precursors, 8−13 boronic acids, 14,15 termethyl-porphyrins, 16 pyridine tautomerization 17 or imidization, 18 imine 19 or amide 20 formation, and phthalocyanine macrocyclization. 21 Many of these attempts were not further reproduced because the polymerization reaction was poorly controlled and did not produce high yield or extended order. Indeed, the growth process of a covalent network is highly nonlinear: the optimum parameters required at the very early stage of polymer growth (when individual monomers react with each others) may vary substantially from those necessary when intermediate oligomers are already formed. In addition, the irreversible character of a covalent bond precludes formation of the thermodynamically most stable structure through defect self-healing. As a consequence, a large number of defects are usually observed 12,14,20 or the polymer domains are limited in size. 8 The defects can arise from incomplete reaction between the reactants due to steric hindering in 2D confinment or from the relative flexibility of the covalent bond that allows easy formation of various geometries with limited stress. 9,14,22,23 We showed previously that the concepts of covalent organic frameworks (COFs) based on the chemistry of boronic acids 24 can be successfully used to create extended surface covalent organic frameworks (SCOFs). 14 Reactions based on Ullmann coupling of halogen-functionalized precursors require similarly some attention. Very high order could be achieved in one-dimensional systems, 25,26 and polymers with reasonable order were demonstrated in 2D environments. 8,9,11−13 Lackinger and co-workers 27 presented very recently a combined strategy with a dibrominated boronic acid that formed covalent networks through activation of two different coupling reactions. Here we propose a similar strategy with a monobrominated boronic acid molecule and formation of a covalent network in two steps (see Figure 1): the reaction between boronic acid moeties took place readily at room temperature, while the Ullmann coupling
The Journal of Physical Chemistry C 01/2012; 116(7):4819−4823. · 4.80 Impact Factor
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ABSTRACT: A series of iridium(III) complexes was designed and investigated as new potential photocatalysts for radical polymerization reactions. The photocatalytic reduction cycle involves the combination of an iridium complex with an amine (e.g., N-methyldiethanolamine) and an alkyl halide (e.g., phenacylbromide). The different three-component systems herein investigated are very attractive for acrylate polymer-ization upon visible light irradiation. They are much more reactive than those based on Ru(bpy) 3 2+ . Free radicals generated during the reaction were investigated by ESR spectroscopy and the chemical mechanisms are discussed. The crucial role played by the photocatalyst (reduction ability and excited state lifetime) is also demonstrated. P hotoredox catalysis has clearly emerged in the synthetic community as a valuable strategy for the smooth generation of free radicals under very soft irradiation conditions (e.g., sunlight, household fluorescence or LED bulbs, and Xenon lamp). 1−3 The use of Ru(bpy) 3 2+ as a photocatalyst is now well-documented in organic chemistry. It is characterized by an excellent visible light absorption property and can work through either an oxidation or a reduction cycle. Very recently, this photoredox catalysis approach was introduced into the polymer chemistry area to initiate a free radical promoted cationic photopolymerization (FRPCP) or a free radical photopolymerization. This novel way extends the development and the design of photoinitiators and photo-sensitizers for fast polymerization reactions (see, e.g., ref 4) usable in various applications. 5 For example, Ru and Ir based complexes in combination with a silane and an iodonium salt work in FRPCP through an oxidation cycle. 6,7 The Ru complex/amine/phenacyl halide system to initiate a polymer-ization reaction is presumably in this free radical polymerization area the first example of a photocatalyst that operates according to a reduction cycle 6a (where the Ru(bpy) 3 2+ excited state reacts with a sacrificial quencher (the amine) to generate its reduced form (Ru(bpy) 3 +), with this latter species being a strong reducing agent leading to the formation of carbon-centered radicals by reaction with the halide). This system exhibits, however, a relatively low efficiency in free radical polymerization. In a more recent paper, a somewhat similar system (Ru complex/amine/ethyl-2 bromoisobutyrate) was proposed, but the efficiency remains low (20−30% MMA conversion for 4 h exposure to a 25 mW/cm 2 Xe lamp). 8 In the present paper, photoinitiating systems based on iridium complexes IrCs (Scheme 1), N-methyldiethanolamine (MDEA), and phenacylbromide (PABr) are presented as novel photocatalysts exhibiting a high efficiency in free radical polymerization (Scheme 2). Their polymerization ability will be checked. The underlying chemical mechanisms will be investigated by electron spin resonance (ESR) and lumines-cence experiments. IrCs for free radical polymerization: The free radical polymerization of pentaerythritol tetraacrylate (EPT) in laminate in the presence of Ir_b/MDEA/PABr is very efficient under visible light (Figure 1A, curve 5): no inhibition time, Rp/ [M 0 ] = 0.245 s −1 , 60% EPT conversion within 20 s under the Xe lamp exposure. In the absence of MDEA (or PABr), the
ACS Macro Letters. 01/2012; 1(2):286−290.
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Mohamad-Ali Tehfe,
Jacques Laleveé,
Sofia Telitel,
Emmanuel Contal,
Freeic Dumur, Didier Gigmes,
Denis Bertin,
Malek Nechab,
Bernadette Graff,
Fabrice Morlet-Savary,
Jean-Pierre Fouassier
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ABSTRACT: Different polyaromatic structures (truxene derivatives and tris(aza)pentacene) are presented as new metal-free organic photocatalysts (OPC) to promote free radical polymerization FRP and ring-opening polymerization (ROP) under halogen lamp, household LED bulb, and laser diode (405 nm). These OPCs exhibit interesting light absorption properties and lead, through an oxidative catalytic cycle, to the formation of radicals and ions that can initiate both free radical polymerization FRP and ring-opening polymerization ROP. Interestingly, excellent polymerization profiles are obtained even upon visible light exposure. Using these very soft irradiation conditions, acrylate/epoxide blends are also easily polymerized under air and lead to the formation of interpenetrated polymer networks IPN exhibiting no phase separation. ■ INTRODUCTION Photoredox catalysis has emerged recently in organic chemistry 1−4 and has been also extended to the photo-polymerization area where the photocatalyst (PC) behaves as a photoinitiator catalyst. 5 This approach is now clearly recognized as a valuable approach for radical initiation under very soft irradiation conditions (sunlight, LED bulbs, fluorescence bulbs, etc.). Photocatalysts mainly involve Ru or Ir metal complexes. However, the search for metal-free organophotocatalysts OPC is actually very important to avoid the high cost of the actual metal-based PCs. Two approaches based on organic dyes or polyaromatic compounds were recently proposed as OPCs for organic 6 or polymer 7 synthesis. For example, the 9,10-bis[(triisopropylsilyl)ethynyl]anthracene (or pyrene, anthra-cene, naphthacene, and pentacene)/diphenyliodonium salt (Ph 2 I +)/silane ((TMS) 3 Si−H) systems allow the photo-initiation of the ring-opening polymerization (ROP) of epoxides and to a lesser extent the free radical polymerization of acrylates (FRP). 7 FRP can be achieved using pyrene (or anthracene, naphthacene, and pentacene)/amine/phenacyl bromide combinations, but the efficiency of the process remains relatively low. 7b The development of a unique dual initiating system for the manufacture of interpenetrated polymer networks IPNs is highly worthwhile to avoid the actual use of a combination of radical and cationic photoinitiators. Moreover, cationic photo-initiators (e.g., onium salts) being only sensitive to UV light, 8 the synthesis of IPNs under visible light remains a challenge where the photoredox catalysis can be highly successful. Therefore, in the present paper, we search for new highly efficient visible light-absorbing OPCs being able to initiate either FRP or ROP so that acrylate/epoxide blends can also be photopolymerized, allowing the synthesis of interpenetrated polymer networks (IPN). The proposed OPCs (Scheme 1) are based on polyaromatic chromophores (truxene derivatives and tris(aza)pentacene; pyrene and the iridium complex Ir(piq) 3 (with piq =
Macromolecules 01/2012; · 5.17 Impact Factor
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ABSTRACT: Photoredox catalysis is now well-known in organic synthesis for the formation of free radicals under very soft irradiations conditions (e.g. sunlight, household fluorescence or LED bulbs, Xe lamp). This method has been introduced here to the polymer chemistry area to initiate ring opening polymerizations (ROP) or free radical polymerizations (FRP). The present paper will give an up-to date situation of the photocatalyst achievements in FRP and ROP.
CHIMIA International Journal for Chemistry 01/2012; 66(6):439-41. · 1.21 Impact Factor
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ABSTRACT: Iridium(III) complexes were designed and evaluated as efficient photoinitiators of polymerization reactions in combination with iodonium salts and silanes. Mechanistically, these reactions were shown to proceed through oxidative photoredox catalysis, generating aryl and silyl radicals under very soft irradiation conditions (blue LED, xenon lamp, and even sunlight). These radicals can initiate the free radical polymerization of acrylates or can be oxidized during the catalytic cycle to promote the ring-opening polymerization of epoxy monomers. Remarkably, both the (photo)chemical reactivity and the practical efficiency are dramatically affected by the ligands. In addition, the central role played by the oxidation ability of the excited state of the photocatalyst is discussed.
Chemistry 11/2011; 17(52):15027-31. · 5.93 Impact Factor
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Gihane Nasr,
Audrey Guerlin,
Frédéric Dumur,
Layla Beouch,
Eddy Dumas,
Gilles Clavier,
Fabien Miomandre,
Fabrice Goubard, Didier Gigmes,
Denis Bertin,
Guillaume Wantz,
Cédric R Mayer
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ABSTRACT: Two iridium(III) soft salts based on ion-paired dinuclear cationic and mononuclear anionic complexes were designed and investigated as phosphorescent emitters for solution processed OLEDs. New dinuclear cationic complexes were prepared with two different bridging ligands, a carbazole and a phenylene spacer. Best devices were designed with the soft salt bearing a carbazole moiety.
Chemical Communications 09/2011; 47(38):10698-700. · 6.17 Impact Factor
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ABSTRACT: a b s t r a c t Phosphorescent Organic Light-Emitting Diodes (PhOLEDs) based on iridium (III) soft salt were designed and studied. Heteroleptic anionic iridium complex (A) was prepared with thiocyanate anions and cationic iridium complex (C) was synthesized with 4,4 0 -dinonyl-2,2 0 -byridine as the ancillary ligand. Electronic and spectroscopic properties of the resulting combination of soft salt CÁA were investigated by mean of UV–visible absorption, fluores-cence spectroscopy and cyclic voltammetry. DFT calculations were also performed and the electroluminescent performances evaluated. Light-emitting electrochemical cells (LECs) dis-playing color-variable emission were also obtained. This color tunability aroused from a modification of the molecular packing of the emissive layer with the temperature. Ó 2011 Elsevier B.V. All rights reserved.
Organic Electronics 08/2011; 12(10):1683–1694. · 4.05 Impact Factor
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Gold bulletin 06/2011; 44:119–137. · 3.52 Impact Factor
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ABSTRACT: The properties of poly(D,L-lactide)-block-poly(2-hydroxyethyl acrylate) (PLA-b-PHEA) block copolymers by means of in vitro / in vivo (rat) degradation are investigated and compared to those of PLA homopolymer. Over 12 weeks, we observe mass loss and molecular weight decrease. In vitro and in vivo findings are very similar for each polymer tested. When a short PHEA block is used (PLA-b-PHEA 15 000-3 000 g · mol(-1) , 85/15 wt%), the degradation process is found to be very similar to that of homo-PLA, and to be typical of a bulk erosion mechanism, with no mass loss observed until week 7 and continuous decrease of molar mass within this timeframe. For a longer PHEA block length within the block copolymer (PLA-b-PHEA 15 000-7 500 g · mol(-1) , 65/35 wt%), the degradation mechanism is modified, with a significant mass loss observed at early times and only a slight decrease in molar mass. The latter finding is related to the pronounced hydrophilicity and softness of the material induced by the PHEA block, which allow easy diffusion and rapid leakage of the degradation residues from the material towards the aqueous medium. Schwann cells are found to better adhere on spin-coated films of PLA-b-PHEA (85/15 wt%) than on PLA ones. These results show the potential of such hydrophilized PLA-based copolymers for use in peripheral nerve repair.
Macromolecular Bioscience 06/2011; 11(9):1175-84. · 3.89 Impact Factor
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ABSTRACT: The synthesis of two random copolymers bearing pendant mixed-ligand orthometallated terpyridine-based cationic iridium (III) complexes, as well as their uses as single-layered electrophosphorescent emitters in polymer light-emitting diodes is described. Both solutionprocessable iridium metallopolymers are prepared by copolymerization of styrene with a complex-substituted styrene by nitroxide mediated polymerization. Results on devices based on metallopolymers used as dopant of poly(N-vinylcarbazole) or alone as single layers are presented.
Macromolecular Chemistry and Physics 06/2011; 212:1616–1628. · 2.36 Impact Factor
